Abstract
Background
Cognitive impairment is a core feature of schizophrenia that can reduce functional capacity and quality of life in patients. However, it is unclear how physicians approach cognitive impairment associated with schizophrenia (CIAS) in real-world clinical practice. This study examines the knowledge, attitudes and practices of psychiatrists towards CIAS in patients.
Methods
This non-interventional, cross-sectional study sampled psychiatrists across the US, UK and Germany with ≥36 months of clinical experience and who treated ≥5 patients with schizophrenia annually. Psychiatrists completed an online survey in December 2022 assessing their knowledge, attitudes and practices towards cognitive impairment in patients with schizophrenia. Outcome variables were analysed descriptively (patient estimates: median [IQR]; psychiatrist characteristics: n [%]).
Results
Overall, 121 eligible psychiatrists completed the survey. Psychiatrists estimated that 50.0 % (28.0;80.0) of patients with schizophrenia exhibited cognitive impairment and diagnosed CIAS in 25.0 % (10.0;50.0) of patients. CIAS symptoms reportedly worsened over time and were transient in 50.0 % (30.0;70.0) and 20.0 % (10.0;30.0) of patients, respectively. Working and studying were ranked the activities of daily living most disrupted by CIAS by 48.8 % (n = 59) of psychiatrists. Only 18.2 % (n = 22) of psychiatrists were aware of effective CIAS treatments and 59.5 % (n = 72) did not administer medication for CIAS. Psychiatrists employed a watch-and-wait strategy in 50.0 % (20.0;70.0) of patients with CIAS.
Conclusions
This study demonstrates limited consensus among psychiatrists regarding CIAS characterisation, diagnosis and management. These insights highlight an unmet need for effective diagnosis and treatment of CIAS, necessitating further research to improve the evidence base for clinical guidelines informing CIAS management.
Keywords: Schizophrenia, Cognitive impairment, Patient characteristics, Psychiatrists, Real-world
Highlights
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While many patients with schizophrenia had signs of CIAS, most were not diagnosed.
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Psychiatrists did not frequently use instruments to diagnose CIAS in patients.
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CIAS symptoms most frequent in patients were social cognition and reduced attention.
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Psychiatrists in western countries had limited consensus on CIAS characterisation.
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Few psychiatrists knew of effective CIAS treatments; 50 % opted to watch-and-wait.
1. Introduction
Schizophrenia is a chronic psychiatric disorder estimated to affect ~24 million individuals worldwide (World Health Organization, 2022) with symptomatology spanning 3 domains: positive symptoms, negative symptoms, and cognitive impairment (Rosenbrock et al., 2023). The condition imposes a considerable morbidity burden that is largely attributable to the early onset of symptoms in late adolescence or early adulthood, low remission rates and reduced quality of life (Charlson et al., 2018; Laursen et al., 2014). Historically, positive symptoms have received greater attention in clinical practice than negative symptoms and cognitive impairment when assessing treatment response in schizophrenia (Harvey et al., 2022). However, negative symptoms and cognitive impairment both contribute to the morbidity imposed by schizophrenia, with cognitive impairment associated with schizophrenia (CIAS) affecting executive function, attention, memory, learning and social cognition (Harvey et al., 2022; McCutcheon et al., 2020; Owen et al., 2016; Mascio et al., 2021).
The burden of schizophrenia is exacerbated by a lack of treatment options for CIAS, for which there are no approved pharmacological treatments available. Furthermore, anti-psychotics remain the only licensed pharmacological treatment for schizophrenia despite their limited clinical benefit beyond targeting positive symptoms (Rosenbrock et al., 2023; Harvey et al., 2022; McCutcheon et al., 2020). Meanwhile, non-pharmacological treatment options for CIAS are also limited, with cognitive remedial therapy (CRT) being one of a few treatments recommended for CIAS in clinical practice guidelines (Hasan et al., 2020; Keepers et al., 2020; National Institute for Health and Care Excellence (NICE), 2020). However, the evidence for CRT is mixed, with an estimated 44 % of patients unable to achieve benefit with CRT (Reser et al., 2019).
CIAS also remains largely unacknowledged in clinical guidelines for schizophrenia, with a notable absence in the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and the International Classification of Diseases 11th Revision (ICD-11) (McCutcheon et al., 2023; American Psychiatric Association, 2013; International Statistical Classification of Diseases and, 2019). Due to the limited clinical guidance and treatment options, it is unclear to what extent physicians acknowledge and diagnose CIAS. Previous literature has highlighted differing perceptions of CIAS among clinicians and between patients, caregivers and clinicians, though findings have predominantly been drawn from single-country contexts (Caqueo-Urízar et al., 2015, Caqueo-Urízar et al., 2016; Vita et al., 2025; Sumiyoshi et al., 2025). In the current study, psychiatrists' knowledge, attitudes, diagnostic practices and management of CIAS were assessed across 3 countries, providing cross-country insights into real-world clinical practice.
The objectives for this study were to comprehensively describe psychiatrists' knowledge, attitudes and practices towards the presentation and diagnosis of CIAS, to outline psychiatrist-reported characteristics of patients with CIAS and to explore psychiatrists' practice regarding the monitoring, management and treatment of CIAS in patients.
2. Methods
2.1. Study design
This multinational, non-interventional, cross-sectional study was conducted across the United States (US), the United Kingdom (UK) and Germany. Sampling was distributed evenly across the 3 countries, with a minimum of 30 psychiatrists recruited in each country. Psychiatrists were asked to complete a bespoke online survey in December 2022 on their attitudes and practices regarding the presentation, diagnosis, treatment and management of CIAS.
2.2. Participants
Psychiatrists practicing in hospital or community centres were identified through convenience sampling of an opt-in psychiatrist panel. Psychiatrists were eligible to participate if they treated ≥5 patients with schizophrenia annually and had ≥36 months of clinical practice experience, including 12 months in their practicing country (US, UK or Germany). Eligible psychiatrists provided informed consent prior to survey completion.
2.3. Data sources
Psychiatrists were emailed a link (live for 1 month) to a secure server hosting the online psychiatric survey that permitted a single entry per psychiatrist account. Prior to completion, psychiatrists underwent eligibility screening and, if eligible, had the option to complete the survey after providing informed consent. A subject screening log was maintained in the study electronic portal, recording basic information on all eligible psychiatrists who were invited to participate in the study. The survey took ≤20 min to complete and comprised 53 questions over 8 sections: eligibility for survey completion (5 questions); psychiatrist baseline characteristics (6 questions); psychiatrist knowledge, attitudes and practices towards diagnosing CIAS (10 questions); psychiatrist characterisation of CIAS in patients (12 questions); psychiatrist characterisation of patients with CIAS (8 questions); treatment of patients with CIAS (8 questions); monitoring and follow-up of patients with CIAS (1 question); recording of CIAS in medical charts (3 questions). The survey included both closed-ended (single and multiple answer, yes/no, Likert scale, rating scale) and open-ended free-text questions.
2.4. Data analysis
All outcome variables were analysed descriptively using SAS® version 9.4 or later and presented overall and separately by country. Categorical variables were summarised by number and proportion, and continuous variables by mean (standard deviation [SD]), median (interquartile range [IQR]) and range. The frequency of missing responses was recorded. Post-hoc analyses stratified by practice experience (<10 or ≥10 years) were performed, where appropriate. All data received from participants were de-identified.
3. Results
Overall, 648 psychiatrists were invited to participate in the survey and 130 (20.1 %) accepted the invitation. Of these, 121 psychiatrists (US: 41, UK: 40, Germany: 40) fulfilled eligibility criteria and completed the survey. The most common reason for exclusion was not fulfilling the minimum clinical practice requirement of ≥36 months (7/9, 77.8 %) (Supplementary Fig. 1).
3.1. Participant characteristics
Most psychiatrists reported general adult as a psychiatric speciality (n = 117, 96.7 %), and ≥15 years was the most commonly reported length of experience (n = 55, 45.5 %) (Table 1). Psychiatrists were predominantly male across all 3 countries (US: n = 28, 68.3 %; UK: n = 24, 60.0 %; Germany: n = 32, 80.0 %). The median [IQR] annual number of psychiatric patients seen by participating psychiatrists was 800 [400, 1200], including 150 [75, 300] patients with schizophrenia.
Table 1.
Respondent characteristics.
| US (N = 41) |
UK (N = 40) |
Germany (N = 40) |
Overall (N = 121) |
||
|---|---|---|---|---|---|
| Age range, n | <30 years | 1 (2.4) | 2 (5.0) | 2 (5.0) | 5 (4.1) |
| 30–39 years | 18 (43.9) | 14 (35.0) | 6 (15.0) | 38 (31.4) | |
| 40–49 years | 9 (22.0) | 13 (32.5) | 18 (45.0) | 40 (33.1) | |
| 50–59 years | 5 (12.2) | 8 (20.0) | 11 (27.5) | 24 (19.8) | |
| ≥60 years | 8 (19.5) | 3 (7.5) | 3 (7.5) | 14 (11.6) | |
| Sex, n (%) | Female | 13 (31.7) | 16 (40.0) | 8 (20.0) | 37 (30.6) |
| Male | 28 (68.3) | 24 (60.0) | 32 (80.0) | 84 (69.4) | |
| Years of practicing psychiatry, n (%) | 0 to <3 years | 0 | 0 | 0 | 0 |
| 3 to <5 years | 3 (7.3) | 7 (17.5) | 2 (5.0) | 12 (9.9) | |
| 5 to <10 years | 17 (41.5) | 5 (12.5) | 6 (15.0) | 28 (23.1) | |
| 10 to <15 years | 7 (17.1) | 7 (17.5) | 12 (30.0) | 26 (21.5) | |
| ≥15 years | 14 (34.1) | 21 (52.5) | 20 (50.0) | 55 (45.5) | |
| Setting of practice, n (%) | Inpatient | 1 (2.4) | 5 (12.5) | 5 (12.5) | 11 (9.1) |
| Outpatient | 19 (46.3) | 8 (20.0) | 15 (37.5) | 42 (34.7) | |
| Both | 21 (51.2) | 27 (67.5) | 20 (50.0) | 68 (56.2) | |
| Psychiatric specialty, n (%)a | Child and adolescent | 12 (29.3) | 2 (5.0) | 2 (5.0) | 16 (13.2) |
| General adult | 41 (100.0) | 37 (92.5) | 39 (97.5) | 117 (96.7) | |
| Geriatric | 9 (22.0) | 3 (7.5) | 7 (17.5) | 19 (15.7) | |
| Forensic | 3 (7.3) | 5 (12.5) | 4 (10.0) | 12 (9.9) | |
| Others | 1 (2.4) | 2 (5.0) | 0 | 3 (2.5) | |
| Number of psychiatric patients seen annually, median [IQR] | 650.0 [400.0; 1200.0] | 500.0 [300.0; 1000.0] | 1100.0 [700.0; 1500.0] | 800.0 [400.0; 1200.0] | |
| Number of patients with schizophrenia seen annually, median [IQR] | 125.0 [50.0,300.0] | 150.0 [95.0, 290.0] | 200.0 [90.0, 475.0] | 150.0 [75.0, 300.0] | |
| Proportion of patients with schizophrenia by age group, median [IQR] | <30 years | 30.0 [20.0, 40.0] | 40.0 [30.0, 50.0] | 40.0 [30.0, 45.0] | 35.0 [25.0, 45.0] |
| 30–60 years | 50.0 [40.0, 65.0] | 47.5 [40.0, 52.5] | 50.0 [39.0, 60.0] | 50.0 [40.0, 60.0] | |
| >60 years | 15.0 [10.0, 20.0] | 10.0 [10.0, 20.0] | 10.0 [10.0, 20.0] | 10.0 [10.0, 20.0] | |
Not mutually exclusive categories. IQR, interquartile range.
3.2. Diagnosing and assessing cognitive impairment in schizophrenia
Overall, psychiatrists estimated that a median [IQR] 50.0 % [28.0; 80.0] of their patients with schizophrenia exhibited signs of CIAS (Supplementary Table 1), with psychiatrists in the UK reporting this observation in a smaller number of patients (40.0 % [17.5; 60.0]). Across all countries, CIAS was formally diagnosed in an estimated median 25.0 % [10.0; 50.0] of patients with schizophrenia presenting with signs of cognitive impairment; initiating treatment plans was the predominant motivation for diagnosis (n = 100, 90.1 %). Country-specific estimates were variable, with fewer psychiatrists formally diagnosing patients in the UK versus the US and Germany (median [IQR] proportion of patients: US: 25.0 % [15.0; 60.0]; UK: 15.0 % [6.0; 30.0]; Germany: 32.5 % [20.0; 60.0]). Among psychiatrists who reported not formally diagnosing CIAS (n = 10, 8.3 %), lack of effective treatments (n = 8, 6.6 %) and guidelines (n = 6, 5.0 %) were the most common reasons.
Most psychiatrists (n = 117, 96.7 %) performed a medical history to exclude other causes of observed CIAS and most carried out a prescription review (n = 109, 90.1 %) and blood tests (n = 106, 87.6 %) (Table 2). Psychiatrists did not frequently use instruments to diagnose CIAS in patients. The proportion of psychiatrists who reported using instruments was 14.0 %–81.8 % (Mini-Mental State Examination [MMSE]: 81.8 %, Montreal Cognitive Assessment [MoCA]: 62.0 %, Brief Assessment of Cognition for Schizophrenia [BACS]: 35.5 %, Schizophrenia Cognition Rating Scale [SCoRS]: 32.2 %, Cognitive Assessment Interview [CAI]: 24.0 %, Repeatable Battery for the Assessment of Neuropsychological Status [RBANS]: 22.5 %, MATRICS Consensus Cognitive Battery [MCCB]: 19.0 %, Telephone Interview for Cognitive Status [TICS]: 14.0 %). Even among the more frequently employed instruments (MMSE and MoCA), psychiatrists administered them to few patients (median [IQR] proportion of patients: MMSE: 25.0 % [10.0; 70.0]; MoCA: 20.0 % [0.0; 50.0]).
Table 2.
Psychiatrist approaches to diagnose cognitive impairment in patients with schizophrenia.
| US (N = 41) |
UK (N = 40) |
Germany (N = 40) |
Overall (N = 121) |
|||
|---|---|---|---|---|---|---|
| Test/procedures used by psychiatrists to rule out other potential causes of cognitive impairment, n (%)a | Blood tests | 35 (85.4) | 38 (95.0) | 33 (82.5) | 106 (87.6) | |
| Imaging | 23 (56.1) | 31 (77.5) | 32 (80.0) | 86 (71.1) | ||
| Medical history | 39 (95.1) | 40 (100.0) | 38 (95.0) | 117 (96.7) | ||
| Prescription review | 38 (92.7) | 38 (95.0) | 33 (82.5) | 109 (90.1) | ||
| Other tests used | 3 (7.3) | 6 (15.0) | 4 (10.0) | 13 (10.7) | ||
| No tests performed | 1 (2.4) | 0 (0.0) | 2 (5.0) | 3 (2.5) | ||
| Proportion of patients in which psychiatrists administer instrument to diagnose CIAS | MCCB | Mean [SD] | 1.7 [4.8] | 3.2 [9.6] | 4.2 [11.4] | 3.0 [9.0] |
| Median [IQR] | 0.0 [0.0;0.0] | 0.0 [0.0;0.0] | 0.0 [0.0;1.5] | 0.0 [0.0;0.0] | ||
| Range | [0.0;20.0] | [0.0;50.0] | [0.0;65.0] | [0.0;65.0] | ||
| No use, n (%)b | 35 (85.4) | 33 (82.5) | 30 (75.0) | 98 (81.0) | ||
| RBANS | Mean [SD] | 3.4 [12.4] | 6.6 [15.3] | 5.2 [13.5] | 5.0 [13.7] | |
| Median [IQR] | 0.0 [0.0;0.0] | 0.0 [0.0;6.0] | 0.0 [0.0;0.0] | 0.0 [0.0;0.0] | ||
| Range | [0.0;75.0] | [0.0;80.0] | [0.0;70.0] | [0.0;80.0] | ||
| No use, N (%)b | 34 (82.9) | 29 (72.5) | 32 (80.0) | 95 (78.5) | ||
| BACS | Mean [SD] | 8.7 [19.0] | 10.6 [20.1] | 11.1 [21.4] | 10.1 [20.0] | |
| Median [IQR] | 0.0 [0.0;10.0] | 0.0 [0.0;10.0] | 0.0 [0.0;12.5] | 0.0 [0.0;10.0] | ||
| Range | [0.0;80.0] | [0.0;100.0] | [0.0;85.0] | [0.0;100.0] | ||
| No use, N (%)b | 30 (73.2) | 23 (57.5) | 25 (62.5) | 78 (64.5) | ||
| MoCA | Mean [SD] | 39.8 [38.6] | 24.3 [26.8] | 22.4 [30.2] | 28.9 [33.0] | |
| Median [IQR] | 25.0 [0.0;75.0] | 20.0 [0.0;32.5] | 7.5 [0.0;37.5] | 20.0 [0.0;50.0] | ||
| Range | [0.0;100.0] | [0.0;100.0] | [0.0;100.0] | [0.0;100.0] | ||
| No use, N (%)b | 13 (31.7) | 14 (35.0) | 19 (47.5) | 46 (38.0) | ||
| SCoRS | Mean [SD] | 6.1 [16.8] | 7.3 [15.5] | 11.5 [21.1] | 8.3 [18.0] | |
| Median [IQR] | 0.0 [0.0;0.0] | 0.0 [0.0;7.5] | 0.0 [0.0;17.5] | 0.0 [0.0;10.0] | ||
| Range | [0.0;80.0] | [0.0;70.0] | [0.0;100.0] | [0.0;100.0] | ||
| No use, N (%)b | 31 (75.6) | 28 (70.0) | 23 (57.5) | 82 (67.8) | ||
| CAI | Mean [SD] | 5.7 [16.7] | 5.3 [10.1] | 4.8 [11.8] | 5.3 [13.1] | |
| Median [IQR] | 0.0 [0.0;0.0] | 0.0 [0.0;6.5] | 0.0 [0.0;0.0] | 0.0 [0.0;0.0] | ||
| Range | [0.0;99.0] | [0.0;40.0] | [0.0;50.0] | [0.0;99.0] | ||
| No use, N (%)b | 32 (78.0) | 27 (67.5) | 33 (82.5) | 92 (76.0) | ||
| MMSE | Mean [SD] | 34.6 [36.8] | 46.6 [36.6] | 37.2 [34.9] | 39.4 [36.2] | |
| Median [IQR] | 25.0 [0.0;50.0] | 45.0 [10.0;85.0] | 20.0 [10.0;60.0] | 25.0 [10.0;70.0] | ||
| Range | [0.0;100.0] | [0.0;100.0] | [0.0;100.0] | [0.0;100.0] | ||
| No use, N (%)b | 13 (31.7) | 4 (10.0) | 5 (12.5) | 22 (18.2) | ||
| TICS | Mean [SD] | 2.4 [7.9] | 2.3 [6.5] | 1.7 [7.4] | 2.1 [7.2] | |
| Median [IQR] | 0.0 [0.0;0.0] | 0.0 [0.0;0.0] | 0.0 [0.0;0.0] | 0.0 [0.0;0.0] | ||
| Range | [0.0;45.0] | [0.0;30.0] | [0.0;40.0] | [0.0;45.0] | ||
| No use, N (%)b | 35 (85.4) | 32 (80.0) | 37 (92.5) | 104 (86.0) | ||
| Other (free-text), n (%) | 4 (9.8) | 10 (25.0) | 6 (15.0) | 20 (16.5) | ||
| Patients in which psychiatrist uses instrument to identify cognitive impairment, n (%)a | Those exhibiting minor indications of cognitive impairment | 33 (80.5) | 33 (82.5) | 35 (87.5) | 101 (83.5) | |
| Those exhibiting severe indications of cognitive impairment | 34 (82.9) | 35 (87.5) | 36 (90.0) | 105 (86.8) | ||
| Those who expressed concern about their symptoms | 38 (92.7) | 34 (85.0) | 33 (82.5) | 105 (86.8) | ||
| Those with a family member or caregiver who expressed concern about patient's symptoms | 36 (87.8) | 37 (92.5) | 33 (82.5) | 106 (87.6) | ||
| Other (free text) | 1 (2.4) | 1 (2.5) | 0 (0.0) | 2 (1.7) | ||
| Missing | 1 (2.4) | 1 (2.5) | 0 (0.0) | 2 (1.7) | ||
BACS, Brief Assessment of Cognition for Schizophrenia; CAI, Cognitive Assessment Interview; IQR, interquartile range; MCCB, MATRICS Consensus Cognitive Battery; MoCA, Montreal Cognitive Assessment; MMSE, Mini-Mental State Examination; RBANS, Repeatable Battery for the Assessment of Neuropsychological Status; SCoRS, Schizophrenia Cognition Rating Scale; SD, standard deviation; TICS, Telephone Interview for Cognitive Status.
Not mutually exclusive categories.
Occurs when the proportion of patients that the psychiatrist uses the instrument in is equal to 0 %.
Most psychiatrists (n = 112, 92.6 %) reported being able to differentiate between mild, moderate and severe CIAS in clinical practice; findings were consistent across all 3 countries (Table 3). Among these psychiatrists, most assessed CIAS severity using clinical judgement (n = 108, 89.3 %), deficits in daily living activity (n = 94, 77.7 %) or assessment instruments (n = 73, 60.3 %). In terms of assessment instruments, most psychiatrists used the MoCA and MMSE to assess severity (MMSE: 66.1 %, MoCA: 63.6 %, BACS: 33.9 %, SCoRS: 31.4 %, MCCB: 29.8 %, RBANS: 28.9 %, CAI: 24.0 %, TICS: 16.5 %). A higher proportion of psychiatrists in the US and UK reported administering instruments to assess CIAS severity versus Germany (US: n = 26, 63.4 %; UK: n = 27, 67.5 %; Germany: n = 20, 50.0 %). Although the MMSE and MoCA were the more frequently employed instruments, the overall psychiatrist population did not report administering them to many patients (median [IQR] proportion of patients: MMSE: 15.0 % [0.0; 50.0] and MoCA: 15.0 % [0.0; 50.0]). Use of the MoCA varied by country (median [IQR] proportion of patients: US: 40.0 % [0.0; 75.0]; UK: 10.0 % [0.0; 30.0]; Germany: 10.0 % [0.0; 40.0]) while use of the MMSE was mostly consistent (median [IQR] proportion of patients: US: 10.0 [0.0; 50.0]; UK: 10.0 [0.0; 50.0]; Germany: 15.0 [0.0; 70.0]).
Table 3.
Psychiatrist approaches to assessing severity of CIAS.
| US (N = 41) |
UK (N = 40) |
Germany (N = 40) |
Overall (N = 121) |
|||
|---|---|---|---|---|---|---|
| Psychiatrists' ability to differentiate between mild, moderate and severe cognitive impairment, n (%) | No | 3 (7.3) | 3 (7.5) | 3 (7.5) | 9 (7.4) | |
| Yes | 38 (92.7) | 37 (92.5) | 37 (92.5) | 112 (92.6) | ||
| Methods used to assess and assign cognitive impairment severity, n (%) | Based upon assessment instruments and cut-offs | 26 (63.4) | 27 (67.5) | 20 (50.0) | 73 (60.3) | |
| Clinical judgement | 37 (90.2) | 34 (85.0) | 37 (92.5) | 108 (89.3) | ||
| Activities of daily living deficits | 31 (75.6) | 35 (87.5) | 28 (70.0) | 94 (77.7) | ||
| Working/studyinga | 22 (53.7) | 29 (72.5) | 25 (62.5) | 76 (62.8) | ||
| Cleaning/maintaining homea | 27 (65.9) | 28 (70.0) | 22 (55.0) | 77 (63.6) | ||
| Managing moneya | 28 (68.3) | 34 (85.0) | 23 (57.5) | 85 (70.2) | ||
| Moving within the communitya | 21 (51.2) | 24 (60.0) | 23 (57.5) | 68 (56.2) | ||
| Preparing mealsa | 24 (58.5) | 28 (70.0) | 20 (50.0) | 72 (59.5) | ||
| Shoppinga | 28 (68.3) | 33 (82.5) | 23 (57.5) | 84 (69.4) | ||
| Taking medicationsa | 27 (65.9) | 30 (75.0) | 20 (50.0) | 77 (63.6) | ||
| Using telephone/other communicationa | 18 (43.9) | 25 (62.5) | 24 (60.0) | 67 (55.4) | ||
| Other (free text) | 0 (0.0) | 4 (10.0) | 0 (0.0) | 4 (3.3) | ||
| Missing | 3 (7.3) | 3 (7.5) | 3 (7.5) | 9 (7.4) | ||
| Proportion of patients in which psychiatrist used listed instruments to assess CIAS severity | MCCB | Mean [SD] | 3.2 [9.2] | 7.6 [21.0] | 6.5 [15.7] | 5.7 [16.0] |
| Median [IQR] | 0.0 [0.0; 0.0] | 0.0 [0.0; 5.0] | 0.0 [0.0; 0.0] | 0.0 [0.0; 0.0] | ||
| Range | [0.0; 50.0] | [0.0; 100.0] | [0.0; 75.0] | [0.0; 100.0] | ||
| Missing | 3 | 3 | 3 | 9 | ||
| Psychiatrists reporting no use, N (%)b | 30 (73.2) | 27 (67.5) | 28 (70.0) | 85 (70.2) | ||
| RBANS | Mean [SD] | 4.6 [13.5] | 9.2 [19.8] | 4.4 [14.0] | 6.0 [16.0] | |
| Median [IQR] | 0.0 [0.0; 0.0] | 0.0 [0.0; 10.0] | 0.0 [0.0; 0.0] | 0.0 [0.0; 0.0] | ||
| Range | [0.0; 75.0] | [0.0; 80.0] | [0.0; 80.0] | [0.0; 80.0] | ||
| Missing | 3 | 3 | 3 | 9 | ||
| Psychiatrists reporting no use, N (%)b | 31 (75.6) | 26 (65.0) | 29 (72.5) | 86 (71.1) | ||
| BACS | Mean [SD] | 4.6 [10.9] | 8.1 [22.9] | 10.3 [22.2] | 7.6 [19.4] | |
| Median [IQR] | 0.0 [0.0; 0.0] | 0.0 [0.0; 5.0] | 0.0 [0.0; 10.0] | 0.0 [0.0; 5.0] | ||
| Range | [0.0; 50.0] | [0.0; 100.0] | [0.0; 90.0] | [0.0; 100.0] | ||
| Missing | 3 | 3 | 3 | 9 | ||
| Psychiatrists reporting no use, N (%)b | 30 (73.2) | 26 (65.0) | 24 (60.0) | 80 (66.1) | ||
| MoCA | Mean [SD] | 40.9 [37.9] | 21.3 [27.4] | 24.3 [32.9] | 28.9 [33.9] | |
| Median [IQR] | 40.0 [0.0; 75.0] | 10.0 [0.0; 30.0] | 10.0 [0.0; 40.0] | 15.0 [0.0; 50.0] | ||
| Range | [0.0; 100.0] | [0.0; 100.0] | [0.0; 100.0] | [0.0; 100.0] | ||
| Missing | 3 | 3 | 3 | 9 | ||
| Psychiatrists reporting no use, N (%)b | 12 (29.3) | 16 (40.0) | 16 (40.0) | 44 (36.4) | ||
| ScoRS | Mean [SD] | 5.3 [13.8] | 9.6 [23.4] | 11.9 [24.2] | 8.9 [20.9] | |
| Median [IQR] | 0.0 [0.0; 0.0] | 0.0 [0.0; 2.0] | 0.0 [0.0; 10.0] | 0.0 [0.0; 3.5] | ||
| Range | [0.0; 70.0] | [0.0; 100.0] | [0.0; 95.0] | [0.0; 100.0] | ||
| Missing | 3 | 3 | 3 | 9 | ||
| Psychiatrists reporting no use, N (%)b | 30 (73.2) | 27 (67.5) | 26 (65.0) | 83 (68.6) | ||
| CAI | Mean [SD] | 7.3 [21.3] | 5.8 [18.1] | 3.8 [12.3] | 5.6 [17.6] | |
| Median [IQR] | 0.0 [0.0; 0.0] | 0.0 [0.0; 0.0] | 0.0 [0.0; 0.0] | 0.0 [0.0; 0.0] | ||
| Range | [0.0; 99.0] | [0.0; 100.0] | [0.0; 65.0] | [0.0; 100.0] | ||
| Missing | 3 | 3 | 3 | 9 | ||
| Psychiatrists reporting no use, N (%)b | 31 (75.6) | 29 (72.5) | 32 (80.0) | 92 (76.0) | ||
| MMSE | Mean [SD] | 31.2 [37.5] | 28.8 [33.5] | 33.1 [36.8] | 31.0 [35.7] | |
| Median [IQR] | 10.0 [0.0; 50.0] | 10.0 [0.0; 50.0] | 15.0 [0.0; 70.0] | 15.0 [0.0; 50.0] | ||
| Range | [0.0; 100.0] | [0.0; 100.0] | [0.0; 100.0] | [0.0; 100.0] | ||
| Missing | 3 | 3 | 3 | 9 | ||
| Psychiatrists reporting no use, N (%)b | 16 (39.0) | 13 (32.5) | 12 (30.0) | 41 (33.9) | ||
| TICS | Mean [SD] | 1.6 [5.1] | 0.9 [3.4] | 1.2 [5.2] | 1.2 [4.6] | |
| Median [IQR] | 0.0 [0.0; 0.0] | 0.0 [0.0; 0.0] | 0.0 [0.0; 0.0] | 0.0 [0.0; 0.0] | ||
| Range | [0.0; 20.0] | [0.0; 20.0] | [0.0; 25.0] | [0.0; 25.0] | ||
| Missing | 3 | 3 | 3 | 9 | ||
| Psychiatrists reporting no use, N (%)b | 33 (80.5) | 33 (82.5) | 35 (87.5) | 101 (83.5) | ||
| Other (free text), n (%) | 3 (7.3) | 9 (22.5) | 5 (12.5) | 17 (14.0) | ||
| Patients in which psychiatrist uses instrument to assess cognitive impairment severity, n (%)c | Those exhibiting minor indications of cognitive impairment | 32 (78.0) | 25 (62.5) | 27 (67.5) | 84 (69.4) | |
| Those exhibiting severe indications of cognitive impairment | 33 (80.5) | 32 (80.0) | 29 (72.5) | 94 (77.7) | ||
| Those who expressed concern about their symptoms | 35 (85.4) | 27 (67.5) | 29 (72.5) | 91 (75.2) | ||
| Those with a family member or caregiver who expressed concern about patient's symptoms | 35 (85.4) | 30 (75.0) | 27 (67.5) | 92 (76.0) | ||
| Other (free text) | 0 (0.0) | 3 (7.5) | 0 (0.0) | 3 (2.5) | ||
| Missing | 4 (9.8) | 6 (15.0) | 7 (17.5) | 17 (14.0) | ||
BACS, Brief Assessment of Cognition for Schizophrenia; CAI, Cognitive Assessment Interview; IQR, interquartile range; MCCB, MATRICS Consensus Cognitive Battery; MoCA, Montreal Cognitive Assessment; MMSE, Mini-Mental State Examination; RBANS, Repeatable Battery for the Assessment of Neuropsychological Status; SCoRS, Schizophrenia Cognition Rating Scale; SD, standard deviation; TICS, Telephone Interview for Cognitive Status.
The denominator is the total number of the cohort.
Occurs when the proportion of patients that the psychiatrist uses the instrument in is equal to 0 %.
Not mutually exclusive categories.
Most psychiatrists (n = 111, 91.7 %) indicated they record CIAS in the medical records of patients with schizophrenia if present (Supplementary Table 2). Reasons pertaining to health insurance prompted some psychiatrists (n = 13, 10.7 %) to record CIAS, most commonly those in the US.
3.3. Characterising CIAS in patients
Among the 7 key symptoms of CIAS examined, none were reported by psychiatrists as ‘never’ being displayed by patients with schizophrenia (Fig. 1). Deficit in social cognition was the CIAS symptom most frequently ranked as ‘always’ being exhibited by patients, followed by reduced attention. Overall, 77.7 % and 71.7 % of psychiatrists reported patients to ‘always’ or ‘often’ display signs of deficits in speed of processing and reduced attention, respectively. Psychiatrists reported deficits in verbal learning or visual memory as the least frequent symptom displayed by patients. A higher proportion of psychiatrists in the UK reported presentation of deficits in verbal learning or visual memory as the least frequently displayed sign of CIAS in patients versus the US and Germany.
Fig. 1.
Frequency of signs and symptoms of CIAS in patients observed by participating psychiatrists (A) overall, in the (B) US, (C) UK and (D) Germany
CIAS, cognitive impairment associated with schizophrenia.
Other signs and symptoms were reported in free text by 1 (0.8 %) psychiatrist per symptom: aggression, memory issues, task initiation, deficits in language skills, concretism, formal thinker.
Executive functioning deficits were ranked as the most important symptom when assessing CIAS (n = 46, 38.0 %), followed by reduced attention (n = 23, 19.0 %) and deficits in reasoning or problem solving (n = 20, 16.5 %) (Supplementary Fig. 2). Working and studying were ranked as the most disrupted activities of daily living by CIAS (n = 59, 48.8 %) (Fig. 2). Overall, most psychiatrists (n = 99, 81.8 %) reported being able to differentiate between negative symptoms of schizophrenia and symptoms of CIAS (Supplementary Table 3). However, the proportion was lower for psychiatrists based in the US (n = 30, 73.2 %) versus the UK (n = 35, 87.5 %) and Germany (n = 34, 85.0 %).
Fig. 2.
Psychiatrist ranked order of most disrupted activities of daily living by the presence of CIAS in patients (A) overall, in the (B) US, (C) UK and (D) Germany
ADL, activities of daily living; CIAS, cognitive impairment associated with schizophrenia.
Psychiatrists reported that symptoms of CIAS worsened over time in a median [IQR] of 50.0 % [30.0; 70.0] of patients (Supplementary Table 4), with estimates varying by country: US: 60.0 [30.0; 80.0]; UK: 47.5 [20.0; 65.0]; Germany: 50.0 [30.0; 68.0]. Over half of psychiatrists reported the worsening of each key symptom over time, with deficits in executive functioning the most frequently reported symptom to worsen over time (n = 93, 76.9 %). Over one-third (n = 48, 39.7 %) reported triggers for worsening CIAS. The most frequently reported triggers were psychotic relapses (n = 16, 13.2 %); alcohol/drug/substance abuse (n = 11, 9.1 %) and medical issues/illness/episodes/comorbidities (n = 10, 8.3 %). However, over half (n = 71, 58.7 %) were unsure of apparent triggers for worsening CIAS or suggested there were no triggers.
Psychiatrists estimated a median [IQR] of 20.0 % [10.0; 30.0] of patients experience transient CIAS symptoms (Supplementary Table 4). However, estimates varied by country, with psychiatrists in Germany and the US reporting the highest and lowest, respectively (US: 10.0 % [5.0; 20.0]; Germany: 30.0 % [20.0; 40.0]). Reduced attention was the CIAS symptom most regarded as transient (n = 59, 48.8 %). Considerable heterogeneity in responses was present concerning the onset of CIAS, with over half of psychiatrists (n = 68, 56.2 %) believing symptoms develop either before or after a schizophrenia diagnosis, while around one-fifth (n = 26, 21.5 %) believed symptom onset to be after diagnosis only. A greater proportion of psychiatrists in the UK reported that CIAS symptoms developed only after schizophrenia diagnosis versus the US and Germany (US: n = 6, 14.6 %; UK: n = 13, 32.5 %; Germany: n = 7, 17.5 %).
3.4. Characteristics of patients with CIAS
Over half of psychiatrists (n = 65, 53.7 %) indicated that cognitive impairment symptoms were most common in patients with schizophrenia >50 years of age (Supplementary Table 5), with this perspective more common among psychiatrists in the US and UK versus Germany. Similar patterns were observed for psychiatrist-perceived severity of CIAS symptoms by patient age, with a high proportion (n = 66, 54.5 %) suggesting CIAS symptoms to be most severe in patients >50 years of age. A lower proportion of psychiatrists in Germany reported more severe CIAS in patients >50 years of age versus the US and UK (US: n = 27, 65.9 %; UK: n = 27, 67.5 %; Germany: n = 12, 30.0 %).
Most psychiatrists reported CIAS was more prevalent (n = 84, 69.4 %) and severe (n = 92, 76.0 %) among patients with poorly controlled versus well-controlled positive symptoms (Supplementary Table 5). Similarly, most indicated CIAS is both more prevalent (n = 101, 83.5 %) and severe (n = 95, 78.5 %) in patients with poorly controlled versus well-controlled negative symptoms.
3.5. CIAS management and treatment
Over half (n = 64, 52.9 %) indicated that anti-psychotic medications improve CIAS, with remaining psychiatrists either unsure (n = 27, 22.3 %) or indicating that anti-psychotics do not improve CIAS (n = 30, 24.8 %) (Table 4). In a post-hoc analysis, psychiatrists with ≥10 years of practice were more likely to consider that anti-psychotics (n = 49, 60.5 %) improve the symptoms of CIAS than psychiatrists with <10 years (n = 15, 37.5 %). Over 40 % of psychiatrists reported administering medications for CIAS, with anti-psychotics and anti-dementia medications being the most commonly prescribed class (n = 25, 51.0 % and n = 16, 32.7 %, respectively) (Table 4). However, over half of psychiatrists (n = 72, 59.5 %) reported not administering medication to alleviate symptoms of CIAS, with a much higher proportion observed for psychiatrists in the UK versus the US and Germany (US: n = 21, 51.2 %; UK: n = 29, 72.5 %; Germany: n = 22, 55.0 %).
Table 4.
Psychiatrist knowledge, attitudes and practices relating to the pharmacological treatment of cognitive impairment in patients with schizophrenia.
| US (N = 41) |
UK (N = 40) |
Germany (N = 40) |
Overall (N = 121) |
||
|---|---|---|---|---|---|
| Whether anti-psychotic treatments improve the severity of symptoms of cognitive impairment, n (%)a | Unsure | 9 (22.0) | 11 (27.5) | 7 (17.5) | 27 (22.3) |
| No | 14 (34.1) | 9 (22.5) | 7 (17.5) | 30 (24.8) | |
| Yes | 18 (43.9) | 20 (50.0) | 26 (65.0) | 64 (52.9) | |
| Atypical anti-psychoticsa | 17 (94.4) | 19 (95.0) | 26 (100.0) | 62 (96.9) | |
| Typical anti-psychoticsa | 7 (38.9) | 6 (30.0) | 5 (19.2) | 18 (28.1) | |
| Whether anti-psychotic treatments negatively impact the severity of the symptoms of cognitive impairment, n (%)a | Unsure | 11 (26.8) | 8 (20.0) | 7 (17.5) | 26 (21.5) |
| No | 7 (17.1) | 13 (32.5) | 19 (47.5) | 39 (32.2) | |
| Yes | 23 (56.1) | 19 (47.5) | 14 (35.0) | 56 (46.3) | |
| Atypical anti-psychoticsa | 19 (82.6) | 9 (47.4) | 11 (78.6) | 39 (69.6) | |
| Typical anti-psychoticsa | 21 (91.3) | 19 (100.0) | 11 (78.6) | 51 (91.1) | |
| Proportion of patients with CIAS in which psychiatrist conducts additional assessments to investigate the condition further | Mean [SD] | 46.9 [31.1] | 39.0 [30.3] | 38.8 [30.8] | 41.6 [30.7] |
| Median [IQR] | 30.0 [25.0;75.0] | 30.0 [15.0;55.0] | 32.5 [12.5;55.0] | 30.0 [20.0;60.0] | |
| Range | [0.0;100.0] | [0.0;100.0] | [0.0;100.0] | [0.0;100.0] | |
| Proportion of patients with CIAS in which psychiatrist implements a watch-and-wait strategy | Mean [SD] | 47.4 [27.1] | 44.1 [28.8] | 48.0 [29.6] | 46.5 [28.3] |
| Median [IQR] | 50.0 [25.0;70.0] | 47.5 [20.0;70.0] | 50.0 [25.0;70.0] | 50.0 [20.0;70.0] | |
| Range | [0.0;100.0] | [0.0;100.0] | [0.0;100.0] | [0.0;100.0] | |
| Psychiatrist administers any medications to alleviate symptoms of cognitive impairment, n (%) | No | 21 (51.2) | 29 (72.5) | 22 (55.0) | 72 (59.5) |
| Yes, medications listed in free text: | 20 (48.8) | 11 (27.5) | 18 (45.0) | 49 (40.5) | |
| Acetylcholinesterase inhibitora | 5 (25.0) | 2 (18.2) | 0 (0.0) | 7 (14.3) | |
| Anti-psychotics (amisulpride, cariprazine, ariprazole, clozapine, olanzapine)a | 6 (30.0) | 4 (36.4) | 15 (83.3) | 25 (51.0) | |
| N-methyl-d-aspartate (NMDA)-receptor antagonistsa | 2 (10.0) | 0 (0.0) | 0 (0.0) | 2 (4.1) | |
| Antidepressantsa | 3 (15.0) | 3 (27.3) | 3 (16.7) | 9 (18.4) | |
| Anti-dementia medications (memantine and donepezil)a | 10 (50.0) | 4 (36.4) | 2 (11.1) | 16 (32.7) | |
| Ginkgoa | 0 (0.0) | 0 (0.0) | 1 (5.6) | 1 (2.0) | |
| Anticonvulsanta | 0 (0.0) | 1 (9.1) | 0 (0.0) | 1 (2.0) | |
| Cannabidiol (CBD)a | 0 (0.0) | 0 (0.0) | 1 (5.6) | 1 (2.0) | |
| Stimulanta | 1 (5.0) | 0 (0.0) | 0 (0.0) | 1 (2.0) | |
| Antimanic | 1 (5.0) | 0 (0.0) | 0 (0.0) | 1 (2.0) | |
| Proportion of patients with CIAS in which psychiatrist administers medications to alleviate cognitive symptoms | Mean [SD] | 37.3 [32.2] | 21.8 [20.9] | 43.9 [25.8] | 36.2 [28.4] |
| Median [IQR] | 29.0 [7.5;62.5] | 10.0 [5.0;50.0] | 40.0 [20.0;60.0] | 25.0 [10.0;50.0] | |
| Range | [3.0;100.0] | [5.0;60.0] | [10.0;95.0] | [3.0;100.0] | |
| Missing | 21 | 29 | 22 | 72 | |
IQR, interquartile range; SD, standard deviation.
Percentage reporting yes.
In patients exhibiting signs of CIAS, psychiatrists employed a watch-and-wait strategy in a median [IQR] of 50.0 % [20.0;70.0] of patients, which was consistent across all countries (Table 4). Most psychiatrists were either unaware or unsure of effective non-pharmacological treatment options for CIAS, with less than one-fifth (n = 22, 18.2 %) reporting awareness of any effective treatments (Supplementary Table 6). However, over half of psychiatrists (n = 64, 52.9 %) reported prescribing cognitive behavioural therapy for the treatment of CIAS. Other non-pharmacological therapies used by psychiatrists included activities of daily living training (n = 96, 79.3 %) and physical exercise (n = 91, 75.2 %).
4. Discussion
Findings from this study demonstrate there is limited consensus among psychiatrists concerning their knowledge, attitudes, and diagnostic practices, characterisation and management of CIAS. Overall, the demographic characteristics of the psychiatrists included in this study were similar across the US, UK and Germany. Psychiatrists estimated around half of patients with schizophrenia display signs of CIAS, but only formally diagnosed CIAS in one-quarter of these patients. Instruments were not routinely used by psychiatrists to assess CIAS in most patients, but when administered, the MMSE or MoCA were preferred. Psychiatrists displayed inter-country heterogeneity concerning the perceived onset and course of CIAS symptoms, as well as the perceived effectiveness of medications and treatment strategies administered. These differing perceptions may be partially attributable to the varying and often limited discussion of CIAS in national clinical guidelines for schizophrenia, with no cognitive impairment diagnostic criterion in the DSM-5 or ICD-11 (American Psychiatric Association, 2013; International Statistical Classification of Diseases and, 2019). This ambiguity may translate to discrepancies in physician training and thus real-world psychiatric practice, highlighting the need for an established international framework for CIAS.
Our survey contributes to the growing literature on CIAS by extending findings beyond single-country contexts. While prior surveys by Vita et al. and Sumiyoshi et al. have provided valuable insights into the awareness, assessment and management of CIAS in clinical practice, their scope was limited to Italy and Japan, respectively (Vita et al., 2025; Sumiyoshi et al., 2025). By contrast, our study offers a cross-country perspective, broadening understanding across the US, UK and Germany. Awareness of CIAS among psychiatrists was high in both the Italian and Japanese studies (Vita et al., 2025; Sumiyoshi et al., 2025); 86 % of Italian psychiatrists reported that their centre evaluated cognitive function (by testing or clinical interview) in patients with schizophrenia, with 69.2 % of centres using at least one formal cognitive assessment instrument (Vita et al., 2025). Interestingly, in the Italian survey, more CIAS assessments (58.7 %) were undertaken by psychologists than by psychiatrists (37.5 %), and the greatest barriers to CIAS assessment were lack of adequately trained staff and organisational problems (Vita et al., 2025). Meanwhile, in the Japanese study, 72 % of psychiatrists reported that they evaluated CIAS in clinical practice, but only 25 % used objective tests (Sumiyoshi et al., 2025). The varying adoption of CIAS assessment by psychiatrists across the 3 studies may be attributed to cross-country differences between the US, UK, Germany, Italy and Japan, such as differences in clinical guidelines or varying levels of experience among the psychiatrists surveyed. While the present study and Japanese study specified that psychiatrists routinely managed patients with schizophrenia (Sumiyoshi et al., 2025), defined by the number of patients with schizophrenia regularly consulted, the Italian survey targeted medical directors in psychiatry (Vita et al., 2025). Therefore, the psychiatrists surveyed in Italy may not necessarily have regular direct contact with patients with schizophrenia due to their clinical leadership role, and thus their perceptions may not reflect standard clinical practice.
The rate of CIAS in patients with schizophrenia estimated by participating psychiatrists in our survey was 50.0 %. This is lower than the rates reported in studies using validated neuropsychological instruments to assess cognitive function, which reported rates of CIAS varying from 55.0 % to 97.6 %, depending on the instrument used (Reichenberg et al., 2009; Peng et al., 2021; Domingo et al., 2015; Barrios et al., 2018; Goonathilake et al., 2022). It is also lower than in the recent survey of Italian psychiatrists, which reported an estimated CIAS prevalence of 65 % in patients whose neurocognitive function was assessed (Vita et al., 2025), and in the Japanese survey, in which 68 % of patients reported experiencing cognitive impairment (Sumiyoshi et al., 2025). Taken together, these data suggest that the comprehensive assessment of CIAS in patients with schizophrenia is not a priority for psychiatrists in routine clinical practice. Therefore, CIAS may be underdiagnosed as patients are not adequately assessed, with more psychiatrists in the current survey diagnosing CIAS on the basis of clinical judgement or patients' functional capacity than on validated testing. Most psychiatrists in our survey reported the initiation of treatment plans as a reason for diagnosing CIAS, while an absent diagnosis was often explained by the lack of effective treatments and guidelines for those who did not formally diagnose CIAS. These heterogeneous attitudes and approaches concerning CIAS diagnosis highlight a lack of consensus in clinical guidance and may explain the under-recognition of cognitive symptoms reported in previous literature (Harvey et al., 2022; Carbon and Correll, 2014).
Among psychiatrists who diagnosed CIAS, various assessment instruments were utilised to assess CIAS and, when assessing CIAS severity, clinical judgement was generally the preferred approach over assessment instruments. In this study, psychiatrists reported infrequently using instruments to diagnose CIAS and assess its severity in patients with schizophrenia. However, when instruments were administered, the MMSE or MoCA were generally preferred by psychiatrists, which is unsurprising given their ease of use and practicality in clinical settings (Nasreddine et al., 2005; Folstein et al., 1975). The MMSE was also the most commonly used tool by Italian and Japanese psychiatrists in the recently published surveys (Vita et al., 2025; Sumiyoshi et al., 2025). However, none of the physicians completing those surveys reported using the MoCA (Vita et al., 2025; Sumiyoshi et al., 2025), indicating notable differences between countries in the use of validated tools other than the MMSE. Interestingly, neither the MMSE and MoCA are specific to schizophrenia, having been conceptualised to distinguish between mild cognitive impairment and dementia (Ercan Doğu and Kokurcan, 2023). Furthermore, the MMSE has been disputed for its suitability to assess CIAS due to the lack of assessment of executive functions, the symptom ranked by participating psychiatrists as the most important symptom when assessing CIAS (Ercan Doğu and Kokurcan, 2023; Fisekovic et al., 2012). This absence of a systematic assessment for CIAS suggests a clear unmet need, as identified by the European Psychiatric Association (Vita et al., 2022).
When characterising CIAS in patients, psychiatrists most actively evaluated patients for deficits in executive function, reduced attention and reasoning, or problem solving. All major symptoms of CIAS were reported by psychiatrists to be present at least ‘sometimes’ in patients with schizophrenia. Aligning with previous studies (McCutcheon et al., 2020; Sumiyoshi et al., 2025), the present study identified speed of processing as the most affected CIAS domain in patients. Working and studying were the activities of daily living ranked as most disrupted by the presence of CIAS by almost half of psychiatrists in the current study. Similarly, 65 % of Japanese patients with schizophrenia reported being unable to perform tasks they could do previously (e.g. housework, study or work) or the tasks taking longer, 64 % reported being unable to maintain concentration, and 62 % were unable to remember instructions or new information (Sumiyoshi et al., 2025). The identification of these key characteristics may inform the development of CIAS-specific instruments that capture the core symptoms of CIAS in patients and individual functioning in terms of the categories most likely to be disrupted by CIAS. This characterisation of CIAS in patients also highlights the important implications of CIAS and supports previous studies demonstrating the adverse effects of schizophrenia on employment, with 80 % to 90 % of patients estimated to be unemployed (Kitchen et al., 2012; Evensen et al., 2016; Holm et al., 2021). In the Japanese survey, 58 % of the patients with CIAS were employed, but only 4 % as full-time employees (Sumiyoshi et al., 2025). Longitudinal research is needed to establish the relationship between CIAS and employment, the extent to which the impact of CIAS on employment is independent of positive and negative symptoms, and how the association varies throughout the course of illness.
While outside the scope of the present study, Sumiyoshi et al. also assessed psychiatrist-patient interactions on the awareness of CIAS (Sumiyoshi et al., 2025). The Japanese survey found patients' experience of CIAS was not associated with having a psychiatrist who proactively explains CIAS. Notably, only 41 % of informed patients recalled receiving an explanation. However, among patients who reported receiving an explanation of CIAS, there was a higher proportion of patients who reported they were currently experiencing CIAS (50 %) or had previously experienced CIAS (33 %), compared with those who had not received an explanation (35 % and 20 %, respectively). Furthermore, despite ~60 % of patients reporting CIAS-related burdens, only ~40 % of patients reported ongoing experience of CIAS, suggesting some patients may not recognize their CIAS-related burdens as being due to CIAS (Sumiyoshi et al., 2025). These findings underscore the potential importance of psychiatrist-patient interactions for patient awareness of CIAS and suggest that some patients may not fully understand the explanations of CIAS provided by their psychiatrists. Therefore, targeted education for both psychiatrists and patients may be essential to close these knowledge gaps and foster better psychiatrist-patient communication to enhance quality of care for people with CIAS.
Previous studies have demonstrated that CIAS develops before symptom onset and becomes increasingly prominent during the prodromal phase up to the first episode of schizophrenia diagnosis (Harvey et al., 2022; Keefe, 2014; Trotta et al., 2015). However, around one-quarter of psychiatrists in the present study perceived the onset of CIAS symptoms to occur after schizophrenia diagnosis or were unsure of timing. This finding may be attributable to how psychiatrists most likely consult with patients at or post-diagnosis, so are unable to comment on whether CIAS was present beforehand. In addition, psychiatrists indicated that CIAS worsened over time in over half of patients with schizophrenia. It would be beneficial to understand whether this decline in cognition was due to the progression of CIAS itself or related to the natural decline in cognition that occurs with aging. Together with the lack of consensus in existing literature concerning cognitive decline over time and prognosis following initial schizophrenia diagnosis, this highlights a crucial unmet need in patient care that warrants further attention (McCutcheon et al., 2020, McCutcheon et al., 2023; Sponheim et al., 2010).
Currently, there is no pharmacological treatment specifically approved for CIAS and existing literature demonstrates uncertainty concerning the effectiveness of anti-psychotics for this indication (Harvey et al., 2022; Keefe, 2014). Negative and cognitive symptoms have been observed to typically persist after treatment with anti-psychotics, along with their associated functional impairment (Rosenbrock et al., 2023; Owen et al., 2016). The present study reflects this clear unmet need for effective treatment options for CIAS, with most psychiatrists surveyed unaware or unsure of effective treatments for CIAS. Nearly half of psychiatrists surveyed were either unsure whether anti-psychotics improved the severity of CIAS or believed them to have no effect. Non-pharmacological options are limited, with CRT being one of the more promising options, as reflected by its inclusion in clinical practice guidance in the US, UK and Germany (Hasan et al., 2020; Keepers et al., 2020; National Institute for Health and Care Excellence (NICE), 2020). However, around half of the psychiatrists surveyed in our study (52.9 %) reported prescribing cognitive behavioural training to their patients with CIAS, which is similar to the reported use of cognitive behavioural interventions by psychiatrists surveyed in Italy (47.6 %) (Vita et al., 2025). Interestingly, the use of cognitive behavioural therapy was uncommon in the Japanese survey, with around 7 % of surveyed patients who were experiencing CIAS reporting current use (Sumiyoshi et al., 2025). Furthermore, the overall use of non-pharmacological interventions was relatively low in Japan, with a large proportion of the surveyed psychiatrists estimating that ≤40 % of their patients with schizophrenia received any form of non-pharmacological treatment for CIAS (Sumiyoshi et al., 2025). These findings suggest a strong degree of uncertainty among psychiatrists concerning the effectiveness of pharmacological and non-pharmacological treatment options for CIAS and may explain why half of psychiatrists in the current study implemented a watch-and-wait strategy. This hesitancy necessitates research to identify effective treatments for CIAS that can be prescribed to patients in clinical practice.
4.1. Strengths and limitations
This study has several strengths. It is the first study, to current knowledge, to explore psychiatrists' knowledge, attitudes and practices concerning the diagnosis, characterisation and management of CIAS in a multinational context. In addition, the community-based psychiatrists who participated in the survey had regular first-hand experience of managing patients with schizophrenia. The anonymised nature of the survey encouraged transparency from participating psychiatrists in the information they provided. Furthermore, the survey was comprehensive, generating a large amount of real-world data on psychiatrists' approaches across 3 western countries. However, the study may be subject to selection bias due to the convenience sampling method employed, reducing the generalisability of findings to all psychiatrists across the US, UK and Germany. Additionally, the inclusion of closed-ended questions prevented a more nuanced understanding of the data points.
5. Conclusions
This study captured the attitudes and practices of established psychiatrists regarding CIAS in patients across 3 Western countries. While findings indicate some agreement among participating psychiatrists in the frequency of CIAS documentation and diagnosis, a strong degree of heterogeneity was present concerning the perceived prevalence, transience and progression of CIAS, and optimal treatment approaches. These variable perspectives have translated to considerable differences in the routine clinical practice of psychiatrists. Therefore, these insights highlight a crucial unmet need for the effective diagnosis and treatment of CIAS, warranting further research to improve the evidence base for clinical guidelines and, in turn, the health and socioeconomic burden of CIAS.
Glossary
- BACS
Brief Assessment of Cognition for Schizophrenia
- CAI
Cognitive Assessment Interview
- CIAS
Cognitive impairment associated with schizophrenia
- DSM-5
Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition
- ICD-11
International Classification of Diseases 11th Revision
- MCCB
MATRICS Consensus Cognitive Battery
- MMSE
Mini-Mental State Examination
- MoCA
Montreal Cognitive Assessment
- RBANS
Repeatable Battery for the Assessment of Neuropsychological Status
- SCoRS
Schizophrenia Cognition Rating Scale
- TICS
Telephone Interview for Cognitive Status
CRediT authorship contribution statement
Stephanie H. Read: Writing – review & editing, Writing – original draft, Visualization, Validation, Supervision, Methodology, Investigation, Conceptualization. Artak Khachatryan: Writing – review & editing, Supervision, Project administration, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. Theresa A. Cassidy: Writing – review & editing, Writing – original draft, Supervision, Project administration, Methodology, Funding acquisition, Conceptualization.
Funding sources
This study was funded by Boehringer Ingelheim (1346-0066). The sponsor was involved in study design and implementation, as well as data collection, analysis, interpretation, writing the study report and reviewing this manuscript. All authors had final responsibility for the decision to submit for publication.
Declaration of competing interest
SHR and AK are full-time employees of Certara, which has received consulting fees from Boehringer Ingelheim Pharmaceuticals, Inc., to independently conduct the study. TAC is an employee of Boehringer Ingelheim Pharmaceuticals, Inc.
Acknowledgements
The authors would like to thank all the participants/patients, caregivers, healthcare professionals and collaborators at investigator sites who participated in this study.
Medical Writing support (in the form of writing assistance, including preparation of the draft manuscript under the direction and guidance of the authors, collating and incorporating authors' comments for each draft, assembling tables and figures, grammatical editing and referencing) was provided by Ella Ferris, MSc, Avalere Health Global Limited, and was funded by Boehringer Ingelheim.
Footnotes
Supplementary data to this article can be found online at https://doi.org/10.1016/j.scog.2025.100406.
Appendix A. Supplementary data
Supplementary material
Data availability
To ensure independent interpretation of clinical study results and enable authors to fulfil their role and obligations under the ICMJE criteria, Boehringer Ingelheim grants all external authors access to clinical study data pertinent to the development of the publication. In adherence with the Boehringer Ingelheim Policy on Transparency and Publication of Clinical Study Data, scientific and medical researchers can request access to clinical study data when it becomes available on Vivli - Center for Global Clinical Research Data, and earliest after publication of the primary manuscript in a peer-reviewed journal, regulatory activities are complete, and other criteria are met. Please visit Medical & Clinical Trials | Clinical Research | MyStudyWindow for further information.
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