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. Author manuscript; available in PMC: 2026 Mar 24.
Published in final edited form as: J Psychiatr Res. 2022 May 2;151:347–353. doi: 10.1016/j.jpsychires.2022.04.039

Modifiable predictors of self-reported and performance-based functioning in individuals with schizophrenia-spectrum disorders and high levels of negative symptoms

Zanjbeel Mahmood a,b,1, Emma M Parrish a,b,1, Amber V Keller a,b, Hannah C Lykins b, Delaney Pickell c, Eric Granholm d,c, Elizabeth W Twamley c,e,b,*
PMCID: PMC13007921  NIHMSID: NIHMS2152117  PMID: 35533518

Abstract

Individuals with schizophrenia who have high negative symptoms are at high risk for poor functional outcomes. However, the determinants of psychosocial functioning in this group are not well understood. We aimed to examine modifiable predictors of both objective, performance-based functional capacity and social skills, and self-reported functioning in individuals with schizophrenia and schizoaffective disorder and high negative symptoms. Fifty-five adults with moderate-to-severe negative symptoms were administered measures of neuropsychological performance, performance-based functional capacity and social competence, self-reported functioning, psychiatric symptom severity, defeatist/asocial beliefs, and intrinsic motivation. In the context of multiple significant predictor variables identified through bivariate correlations, multiple regression models showed that neuropsychological performance was the only significant predictor of performance-based functional capacity; neuropsychological performance and motivation/pleasure negative symptoms were significant predictors of performance-based social competence. For two different measures of self-reported functioning, intrinsic motivation, asocial beliefs, and diminished expression emerged as significant predictors. Neurocognitive ability was a better predictor of performance-based functional skills whereas motivation and beliefs more strongly predicted self-reported real-world functioning. The findings of this study suggest a complex picture of predictors of performance-based functional capacity (objective neuropsychological functioning) and self-reported functioning (motivation and beliefs), underscoring the clinical and scientific utility of including both self-reported and objective measures of functioning to identify treatment approach. Individuals with high negative symptoms and a cognitive/functional skills deficit may benefit from interventions such as cognitive remediation or skills training, whereas individuals with motivational difficulties may benefit from treatments such as cognitive behavioral therapy.

Keywords: Motivation, Expressive deficits, Functional capacity, Neuropsychological functioning, Psychosis

1. Introduction

Schizophrenia, which affects over 3 million people in the United States (Cloutier et al., 2016), is a leading cause of disability worldwide (Charlson et al., 2018). The societal importance of functional outcomes in schizophrenia is underscored by the significant economic burden associated with functional disability among people with schizophrenia (e.g., lost productivity, need for cargivers; Cloutier et al., 2016). Individuals with high negative symptoms of schizophrenia (e.g., anhedonia, alogia, and amotivation) are at a higher risk for functional compromise given the strong links between this symptom dimension and poor functional outcomes and quality of life (Fenton and McGlashan, 1991; Foussias et al., 2014; Rabinowitz et al., 2012; Robertson et al., 2014; Ventura et al., 2015). These clinical symptoms remain resistant to pharmacological intervention, underscoring the need to understand modifiable predictors of functional outcomes in individuals with high negative symptoms to inform targeted psychosocial treatment development. Performance-based functional capacity and self-reported functioning may represent critical and unique aspects of psychosocial functioning that need to be considered simultaneously within clinical research to effectively address treatment needs. However, the strongest predictors of psychosocial functioning in this subgroup of people with schizophrenia are not well-understood.

In addition to negative symptom severity, neuropsychological functioning is considered a key determinant of functional capacity in individuals with schizophrenia (Lepage et al., 2014). Specifically, impaired cognitive functioning across domains of processing speed, memory, language, visuomotor and spatial skills, attention, and executive functioning is associated with the ability to perform independent activities of daily living and social skills (Bowie et al., 2008; Brüne, 2005; Couture et al., 2011; Rajji et al., 2014). Some studies have reported that neuropsychological impairment is related to impaired self- and informant-reported functioning (Bowie et al., 2008; Couture et al., 2011; Granholm et al., 2008), whereas other studies have reported no relationship between neuropsychological impairment and self-reported functioning or recovery (Morrison et al., 2013; Sabbag et al., 2012). Psychiatric symptoms can also impact functioning in schizophrenia. For instance, depressive symptoms have been linked to worse self- and informant-reported functioning (Bowie et al., 2008; Foussias et al., 2011), but some studies have shown that depressive symptoms are not related to functional capacity (Abramowitz et al., 2014; Harvey et al., 2017). Another study found that clinical and personality factors (i.e., anxiety, depression, negative self-esteem, internal locus of control) related to self-reported functional improvement, i.e., recovery, in schizophrenia; however, negative symptoms and neurocognitive functioning did not (Morrison et al., 2013). Positive symptoms are not usually significantly associated with functional capacity (Bowie et al., 2008; Leifker et al., 2009) and functional outcomes (i.e., independent living, skill acquisition, and social problem solving; Green, 1996; Rabinowitz et al., 2012), though there is some evidence that over extended periods of time, they impair ability to maintain employment and interpersonal relationships (Mohamed et al., 2008; Racenstein et al., 2002). Weaker associations between neurocognitive ability, psychiatric symptoms, and functioning may be partially explained by limited literature examining individuals with elevated symptoms.

Evidence supports a two-factor structure of negative symptoms: expressive and motivational/pleasure deficits (Liemburg et al., 2013; Stiekema et al., 2016). Despite evidence to suggest that motivational deficits have a stronger link to functional outcomes than do expressive deficits (Fervaha et al., 2014a; Foussias et al., 2011; Strauss et al., 2013), many studies have examined negative symptoms as a global score rather than examining the two factors separately (see Cella et al., 2017). Furthermore, motivational deficits, although considered a central component of negative symptoms, have also been measured as an independent construct that is significantly associated with cognition as well as real world functional outcomes (Fervaha et al., 2014b; Saperstein et al., 2011). Defeatist performance beliefs, a related construct defined as unhelpful beliefs about one’s own capacity to complete purposeful actions, are also associated with worse functional capacity and community functioning in schizophrenia (Campellone et al., 2016; Horan et al., 2010).

The current literature has focused on modifiable predictors of psychosocial functioning in populations with mild-to-moderate negative symptom levels. Individuals with high negative symptoms also tend to have worse neuropsychological and functional performance, worse defeatist attitudes and motivation, and poorer overall functioning (Campellone et al., 2016; Green, 2006; Rabinowitz et al., 2012; Ventura et al., 2015). Given the limited exploration of correlates of psychosocial functioning within high negative symptom samples, the current study aimed to identify the strongest modifiable predictors of performance-based functional capacity, as well as self-reported indicators of functioning in this population. Based on prior research in broader schizophrenia samples, we hypothesized that in a high negative symptom sample, neuropsychological functioning would be the strongest predictor of functional capacity, whereas depressive symptoms, motivational deficits, and defeatist beliefs would be the strongest predictors of self-reported functioning. To our knowledge, this is the first study to examine predictors of objective and self-reported functioning in a sample of individuals with schizophrenia and high negative symptom severity.

2. Material and methods

2.1. Participants and procedure

Fifty-five participants with schizophrenia or schizoaffective disorder were enrolled as part of a randomized controlled trial of Cognitive-Behavioral Social Skills Training combined with Compensatory Cognitive Training (Clinical Trial registration number NCT02170051). Inclusion criteria were: 1) ability to provide voluntary informed consent; 2) age 18–65 years old; 3) DSM-IV diagnosis of schizophrenia or schizoaffective disorder based on the Structured Clinical Interview for DSM-IV (SCID-IV; First et al., 2002); 4) moderate to severe negative symptoms based on the Clinical Assessment Interview for Negative Symptoms (CAINS; total score >19, i.e., above the mean in Kring et al., 2013); 5) ≥6th grade reading level on the WRAT-4 Reading subtest (Wilkinson and Robertson, 2006); and 6) stable on psychiatric medications for the prior three months. Exclusion criteria were: 1) previous cognitive behavioral therapy (CBT), social skills training (SST), or compensatory cognitive training (CCT) in the last 5 years; 2) severe depression on the Calgary Depression Scale for Schizophrenia (CDSS >8); 3) ocular damage, disease, surgery, and/or medications that affect pupil dilation; 4) DSM-IV diagnosis of alcohol or substance dependence assessed via the Mini International Neuropsychiatric Interview (MINI) or SCID-IV; 5) requiring a level of care that interferes with outpatient therapy (e.g., hospitalization, severe medical illness). Study procedures have been described in greater detail in prior publications (Granholm et al., 2022; Mahmood et al., 2020). The correlation and multiple linear regression analyses reported in the present study are distinct from and expand upon previous publications with this dataset. All assessments were conducted at the beginning of the clinical trial, prior to any intervention. All study procedures were approved by the University of California, San Diego Institutional Review Board.

2.2. Measures

Functional Skills and Self-Reported Functioning.

Performance-based functional capacity, including domains of financial management and communication, was measured with the UCSD Performance-Based Skills Assessment-Brief (UPSA-B), which has excellent inter-rater reliability (original UPSA ICC = .91), is highly correlated with the original UPSA measure (r = 0.91; Patterson et al., 2001a), and has equivalent specificity to the original measure in identifying people who are living independently (Mausbach et al., 2007). Performance-based social competence was measured with the Social Skills Performance Assessment (SSPA), which uses standardized role-play scenarios of neutral and adversarial social situations, has good to excellent inter-rater (ICC = 0.91) and test-retest reliability (r = 0.92), and adequate construct, discriminative, and convergent validity based on its correlation with other performance-based measures of everyday functioning and well-being (Patterson et al., 2001b). Self-reported functional ability (i.e., self-appraised skills) was measured with a composite score calculated from the Specific Levels of Functioning Scale (SLOF), which has demonstrated construct validity and internal consistency, and a well-defined factor structure (Schneider and Struening, 1983; Mucci et al., 2014). The SLOF was identified as one of the best rating scales for functional outcomes in the NIMH-funded Validation of Everyday Real-World Outcomes (VALERO) study (Harvey et al., 2011). The SLOF composite score reflects the average of the interpersonal relationships, activities, and work skills subdomain ratings. Self-reported engagement in functional activities (i.e., performance in various basic community living skills) was measured with the Independent Living Skills Survey (ILSS; Wallace et al., 2000), which assesses functional activities across ten functional areas not addressed by the SLOF: personal hygiene, appearance and care of clothing, care of personal possessions and living space, food preparation, care of personal health and safety, money management, transportation, leisure and recreational activities, job seeking, and job maintenance. The ILSS is considered an internally consistent (coefficients for subscales range from 0.435-.900) and stable (coefficients for subscales range from 0.418-.904) measure of basic functional living skills that is sensitive to change over time (Wallace et al., 2000). Higher scores across all measures reflect better functioning.

Neuropsychological Measures.

The Wide Range Achievement Test-IV (WRAT-IV; Wilkinson and Robertson, 2006) was administered to estimate premorbid intellectual functioning. Global neuropsychological functioning was measured by averaging the age, gender, and education corrected T-scores of cognitive subtests from the MATRICS Consensus Cognitive Battery (MCCB; Nuechterlein et al., 2008), which assess processing speed (Brief Assessment of Cognition in Schizophrenia subtests: Symbol-Coding, Category Fluency [animal naming], and Trail Making Test, Part A subtests; Keefe et al., 2004), sustained attention (Continuous Performance Test—Identical Pairs; Cornblatt et al., 1988), working memory (Wechsler Memory Scale – Third Edition: Spatial Span and Letter-Number Span subtests; Wechsler, 1997), verbal learning (Hopkins Verbal Learning Test—Revised; Brandt and Benedict, 2001), visual learning (Brief Visual Memory Test—Revised; Benedict, 1997), and executive functioning (Neuropsychological Assessment Battery Mazes; White and Stern, 2003). The MCCB scoring program was used to generate all individual neuropsychological test T-scores, all of which were interpreted as higher scores reflecting better performance. Therefore, a higher mean T-score indicates better global cognitive functioning.

Symptom Severity.

Negative symptom severity was measured using two psychometrically reliable and valid measures: the Clinical Assessment Interview for Negative Symptoms (CAINS, which includes motivation/pleasure and expression subscales; Kring et al., 2013) and the Scale for the Assessment of Negative Symptoms (SANS, which includes motivation and diminished expression subscales; Andreasen, 1989). Positive symptom severity was measured with the positive symptom subscale of the expanded Brief Psychiatric Rating Scale (BPRS; Lukoff et al., 1986). Depressive symptom severity was measured with the Calgary Depression Scale for Schizophrenia (Addington et al., 1990). Higher scores on these measures indicate greater symptom severity. Participants’ insight into symptoms was measured with the Birchwood Insight Scale (Birchwood et al., 1994), where higher scores indicate better insight.

Defeatist Beliefs, Asocial Beliefs, and Intrinsic Motivation.

Defeatist performance beliefs were measured with the Defeatist Performance Attitude Scale (DPAS), a 15-item subscale of the Defeatist Attitude Scale (Grant and Beck, 2010). Asocial beliefs were measured with the Asocial Belief Scale (ABS; Grant and Beck, 2010). Higher scores on both the DPAS and ABS indicate more severe defeatist and asocial beliefs. Intrinsic motivation was evaluated using a derived 3-item measure of sense of purpose, motivation, and curiosity (QLS-3) from the Heinrichs-Carpenter Quality of Life Scale (Heinrichs et al., 1984), used extensively in empirical studies of this construct in people with schizophrenia (Choi et al., 2013; Fervaha et al., 2014b; Gard et al., 2009; Saperstein et al., 2011). A higher score on this 3-item measure indicates better intrinsic motivation.

2.3. Statistical analysis

Race and ethnicity data are reported in Table 1, but for the purposes of our analyses, White/non-Hispanic individuals were coded 0 and compared with all others, who were coded 1. Multiple linear regression was used to examine the strongest modifiable predictors of both performance-based and self-report indices of functioning. To minimize Type II error, covariates were selected based on significance at p < .05 via bivariate Pearson correlations, or Spearman correlations for non-normally distributed variables. When non-modifiable variables also emerged as significant, a hierarchical approach was taken such that those variables were entered into the first block in regression models to control for their potential influence. Model assumptions were met, and residuals were normally distributed. Analyses were conducted using SPSS version 27.0.

Table 1.

Participant demographic characteristics (n = 55).

M±SD Range
Age (years) 50.64 ± 9.77 22–65
Education (years) 11.87 ± 2.22 2–18
Duration of illness (years) 30.27 ± 12.31 3–60
WRAT-IV reading 91.16 ± 11.35 61–126
N %
Gender
 Female 22 40
 Male 33 60
Ethnicity
 Hispanic 18 32.7
 Non-Hispanic 37 67.3
Race
 African American 15 27.3
 American Indian/Alaskan 1 1.8
 Asian 1 1.8
 Native Hawaiian/Pacific Islander 2 3.6
 White 36 65.5
Racial/Ethnic minority 33 60
Never married 33 60
Living independently 34 61.8
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3. Results

Participants had a mean age of 51 years (SD = 9.8) and 12 years of education (SD = 2.2). Most participants were men (60%), and 40% were white/non-Hispanic. Further details regarding the demographic characteristics of the sample are reported in Table 1 and clinical characteristics of the sample are reported in Table 2. Bivariate correlations showed that white/non-Hispanic race and higher WRAT-IV, MCCB global, and QLS-3 scores were associated with better UPSA-B performance (see Table 3 for bivariate correlations). Multiple linear regression determined that, together, these variables explained 52% of the variance in UPSA-B performance (p < .001). The MCCB global cognitive score and QLS-3 uniquely explained 21% of the variance in UPSA-B total score, above and beyond race/ethnicity and premorbid intellectual functioning; however, only the MCCB global score emerged as a statistically significant predictor (p < .001; sr = 0.43; see Table 4 for regression coefficients).

Table 2.

Participant Clinical Characteristics (n = 55)

N %
Diagnosis
 Schizoaffective disorder 19 34.5
 Schizophrenia 36 65.5
Medication class*
 No atypical antipsychotics 3 5.5
 Typical antipsychotics 6 10.9
 Atypical antipsychotics 34 61.8
 Both typical/atypical antipsychotics 2 3.6
M±SD Range
MCCB global 36.99 ± 8.93 19–65
CAINS motivation and pleasure 25.56 ± 3.94 18–34
CAINS expression 1.89 ± 2.60 0–13
SANS diminished motivation 22.04 ± 3.87 13–29
SANS diminished expression 4.43 ± 5.47 0–20
BPRS positive subscale 5.31 ± 2.05 3–10
CDSS depression 1.73 ± 1.74 0–7
BIS insight 8.91 ± 2.19 4–12
ABS asocial beliefs 6.62 ± 3.49 1–15
QLS-3 intrinsic motivation 6.75 ± 2.51 1–13
DPAS defeatist attitudes 52.75 ± 15.73 23–87
UPSA 63.43 ± 17.59 19–90
SSPA 3.02 ± 0.52 2.01–3.96
SLOF 3.82 ± 0.76 1.63–5
ILSS 0.81 ± 0.06 0.65–0.91
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Note:

*

n = 45.

ABS = Asocial Belief Scale; BIS=Birchwood Insight Scale; BPRS=Brief Psychiatric Rating Scale; CAINS=Clinical Assessment Interview for Negative Symptoms; CDSS=Calgary Depression Scale for Schizophrenia; DPAS = Defeatist Performance Attitude Scale; ILSS=Independent Living Skills Survey; MCCB = MATRICS Consensus Cognitive Battery; QLS-3 = Quality of Life Scale; SANS=Scale for the Assessment of Negative Symptoms; SLOF=Specific Level of Functioning; SSPA=Social Skills Performance Assessment; UPSA-B=UCSD Performance-based Skills Assessment; WRAT-IV=Wide Range Achievement Test-Fourth Edition. Atypical antipsychotics: Aripiprazole, Clozapine, Iloperidone, Lurasidone, Olanzapine, Quetiapine, Risperidone, Ziprasidone; Typical antipsychotics: Fluphenazine, Haloperidol, Perphenazine.

Table 3.

Correlations examining predictors of performance-based and self-reported functioning (n = 55).

UPSA
 SSPA
 SLOF
 ILSS
r p r p r p r p
Age 0.03 .807 −0.02 .910 0.02 .897 0.03 .848
Sex 0.12 .370 0.21 .128 0.04 .756 0.03 .848
Race/ethnicity −0.38 .005 −0.17 .208 −0.15 .292 −0.02 .896
Education (years)* 0.22 .106 −0.08 .543 −0.05 .728 0.17 .227
WRAT-IV reading 0.51 <.001 0.09 .515 0.12 .368 0.06 .683
MCCB global 0.66 <.001 0.33 .013 0.22 .114 0.24 .100
CAINS motivation and pleasure <0.01 1.00 −0.32 .019 −0.28 .037 −0.14 .319
CAINS expression* −0.23 .868 −0.09 .517 −0.23 .093 −0.33 .019
SANS diminished motivation 0.02 .867 −0.24 .073 −0.22 .108 −0.12 .387
SANS diminished expression −0.13 .347 −0.13 .334 −0.23 .095 −0.49 <.001
BPRS positive subscale −0.06 .673 −0.11 .434 −0.18 .201 −0.09 .541
CDSS depression 0.06 .668 −0.10 .482 −0.24 .074 −0.22 .115
BIS insight 0.19 .157 −0.12 .392 −0.06 .656 −0.10 .487
ABS asocial beliefs 0.08 .577 −0.13 .353 −0.42 .002 −0.05 .715
QLS-3 intrinsic motivation 0.39 .003 0.31 .023 0.40 .003 0.38 .006
DPAS defeatist attitudes 0.02 .884 −0.10 .489 −0.36 .007 −0.17 .227
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*

Spearman correlation.

Note: ABS = Asocial Belief Scale; BIS=Birchwood Insight Scale; BPRS=Brief Psychiatric Rating Scale; CAINS=Clinical Assessment Interview for Negative Symptoms; CDSS=Calgary Depression Scale for Schizophrenia; DPAS = Defeatist Performance Attitude Scale; ILSS=Independent Living Skills Survey; MCCB = MATRICS Consensus Cognitive Battery; QLS-3 = Quality of Life Scale; SANS=Scale for the Assessment of Negative Symptoms; SLOF=Specific Level of Functioning; SSPA=Social Skills Performance Assessment; UPSA-B=UCSD Performance-based Skills Assessment; WRAT-IV=Wide Range Achievement Test-Fourth Edition. Bold font indicates significant at p < .05.

Table 4.

Predictors of performance-based and self-reported functioning (n = 55).

UPSA-B
b t p-value 95% CI Step 1
Race/ethnicity −4.65 −1.30 .201 −11.857, 2.561 F = 11.35, R2 = 0.31
WRAT-IV Reading 0.27 1.57 .123 −0.076, 0.618
Step 2
MCCB global cognition 0.93 4.37 <.001 0.501, 1.357 F = 13.39, R2 = 0.52
QLS-3 intrinsic motivation 0.97 1.37 .176 −0.451, 2.390
SSPA
b t p-value 95% CI
CAINS motivation/pleasure −0.04 −2.18 .034 −0.072, −0.003 F = 4.85, R2 = 0.23
MCCB global cognition 0.02 2.65 .011 0.005, 0.034
QLS-3 intrinsic motivation 0.02 0.89 .380 −0.030, 0.078
SLOF
b t p-value 95% CI
CAINS motivation/pleasure −0.04 −1.82 .075 −0.086, 0.004 F = 7.81, R2 = 0.39
ABS asocial beliefs −0.06 −2.18 .034 −0.120, −0.005
DPAS defeatist attitudes −0.01 −1.69 .097 −0.023, 0.002
QLS-3 intrinsic motivation 0.10 2.72 .009 0.025, 0.167
ILSS
b t p-value 95% CI
SANS diminished expression −0.004 −2.97 .005 −0.007, −0.001 F = 9.01, R2 = 0.28
QLS-3 intrinsic motivation 0.005 1.55 .127 −0.001, 0.011
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Note: ABS = Asocial Belief Scale; CAINS=Clinical Assessment Interview for Negative Symptoms; DPAS = Defeatist Performance Attitude Scale; ILSS=Independent Living Skills Survey; MCCB = MATRICS Consensus Cognitive Battery; QLS-3 Quality of Life Scale; SANS=Scale for the Assessment of Negative Symptoms; SLOF=Specific Level of Functioning; SSPA=Social Skills Performance Assessment; UPSA-B=UCSD Performance-based Skills Assessment; WRAT=Wide Range Achievement Test-Fourth Edition. Bold font indicates significant at p < .05.

For the SSPA, bivariate correlations showed that lower scores on the CAINS motivation/pleasure subscale, as well as higher QLS-3 and MCCB global scores were associated with better social competence performance. Multiple linear regression determined that, together, these variables explained 23% of the variance in SSPA performance (p = .005), with CAINS motivation/pleasure (p = .034; sr = −.27) and MCCB global scores (p = .011; sr = 0.33) emerging as the only significant predictors.

For the SLOF, bivariate correlations determined that lower scores on the CAINS motivation/pleasure subscale, ABS, and DPAS, as well as higher scores on the QLS-3 were associated with higher SLOF scores. Multiple linear regression determined that, together, these variables explained 39% of the variance in SLOF scores (p < .001), with ABS (p = .034; sr = −.24) and QLS-3 (p = .009; sr = 0.30) emerging as the only significant predictors. For the ILSS, bivariate correlations determined that lower scores on both the CAINS and SANS diminished expression subscales, and higher QLS-3 scores, were associated with higher ILSS scores. Given the significant correlation between the CAINS and SANS expression subscales (r = 0.839), and relatively stronger correlation between SANS diminished expression and ILSS, only SANS diminished expression was included as a predictor to avoid multicollinearity. Multiple linear regression determined that, together, SANS diminished expression and QLS-3 scores explained 28% of the variance in ILSS scores (p < .001), the SANS diminished expression score emerged as the only significant predictor (p = .005; sr = −.37).

4. Discussion

The current study aimed to identify the strongest modifiable predictors of functional skills and self-reported functioning in a sample of individuals with schizophrenia and schizoaffective disorder who have high negative symptom severity. Consistent with our hypotheses and prior research, neurocognitive functioning was a moderate to large predictor of performance-based functional capacity and social competence (Bowie et al., 2008; Brüne, 2005; Couture et al., 2011; Rajji et al., 2014). Also consistent with prior research, neurocognitive functioning did not significantly relate to self-reported measures of psychosocial functioning (Morrison et al., 2013; Sabbag et al., 2012). In addition to better cognitive functioning, less severe motivation and pleasure deficits, as assessed by the CAINS, also had a small-to-medium effect on social competence performance. Current research suggests a two-factor structure of negative symptoms comprising of amotivation/sociality and diminished expression (Stiekema et al., 2016), with amotivation having a stronger association with objective, performance-based and self-reported or informant-reported functional outcomes than diminished expression (Fervaha et al., 2014a; Foussias et al., 2011; Strauss et al., 2013). The results of our study underscore the importance of monitoring motivation and pleasure deficits in addition to cognitive functioning to identify those at greatest risk for functional compromise.

Although intrinsic motivation correlated with better psychosocial functioning across all skill-based and self-report measures, in regression analyses, it only emerged as a significant, moderate predictor of self-reported functional abilities as measured by the SLOF. Moreover, regression analyses indicated a small-to-medium effect of asocial beliefs in predicting self-reported functional ability. Diminished expression, as measured by SANS, was the only significant, moderate-sized predictor of self-reported functional activities (ILSS). Though asocial beliefs emerged as a significant contributor of self-reported functioning, there is overlap between asocial beliefs, defeatist beliefs, and negative symptoms (Beck et al., 2013; Granholm et al., 2018). Additionally, though amotivation often has a stronger association with functional outcomes than does diminished expression, the latter still remains associated with poor real-world functional outcomes (Fervaha et al., 2014a; Strauss et al., 2013), and there is some evidence that more prominent diminished expression is linked to more severe overall negative symptoms (Strauss et al., 2013). Previous studies have been inconsistent in their evidence for an association between negative symptom severity and self-reported psychosocial functioning, (İpçi et al., 2020; Morrison et al., 2013; Rabinowitz et al., 2012; Robertson et al., 2014); however, these have been limited to examining negative symptoms as a unitary construct.

Our findings underscore the clinical and scientific importance of examining negative symptom subdomains given their differential associations with self-reported functional abilities and engagement in functional activities. Importantly, performance-based measures of functional capacity (e.g., UPSA, SSPA) may not always converge with real-world community functioning (Harvey et al., 2007), e.g., due to low motivation to engage in activities in the real world. Thus, improvements in cognition may need to occur in the context of motivational improvements to result in improved community functioning. Overall, these findings may reflect this distinction between predictors of functional capacity and self-reported real-world functioning, as people may possess functional skills but not use them due to dysfunctional beliefs or poor motivation. It is possible that dysfunctional beliefs and amotivation bias responses on self-report measures, thereby underscoring the importance of including both objective and self-report measures of functioning to determine moderating risk and protective factors for targeted treatment development.

Our hypothesis that depressive symptoms and defeatist beliefs would be predictive of self-reported functioning was not supported. This is likely due to the restricted range of depressive symptom severity within the current sample consequent to the exclusionary criteria designed to capture primary rather than secondary negative symptoms (Kirschner et al., 2017; Majadas et al., 2012). As such, the results may not generalize to samples with high primary and secondary negative symptoms and warrants future investigation. Furthermore, the lack of finding with defeatist beliefs may partially be due to overlap between measures of defeatist beliefs and negative symptoms, and there may be limited range in this measure among people with high negative symptoms.

Overall, we found that cognitive abilities and negative symptom severity, particularly motivation/pleasure deficits, were more relevant for performance-based functional capacity and social skills, whereas intrinsic motivation, asocial beliefs, and expressive deficits were better predictors of self-reported functional ability and activities. It is possible that divergent predictors of performance-based versus self-reported functioning emerged due to imperfect convergence among the measures selected in the study. For example, although the UPSA and ILSS share money management as a subdomain (the former assesses skills whereas the latter assesses activities), the ILSS was unique in gauging involvement in activities for which there was no comparable skills assessment (e.g., transportation, food preparation/storage). Future studies with individuals with high negative symptoms should consider evaluating functional capacity and self-reported functioning within similar domains to better elucidate shared and distinct predictors that may serve as treatment targets for this high-risk schizophrenia subpopulation.

There are a few limitations of the current study to be considered. First, our sample size was small. Participants in the study were stable outpatients and, consequently, the results may not generalize to those with severe positive symptoms or inpatient populations; our results should also be replicated in younger and less chronically ill samples. Furthermore, there are other predictors of functioning that have been studied in the extant literature (e.g., social cognition) that we did not examine in the current study. Additionally, the cross-sectional nature of the study precludes causal inference. Directions for future research could include longitudinal investigations to understand the enduring relationships between neuropsychological and clinical correlates of functioning in the context of high negative symptom severity, as well as examination of other modifiable predictors of functioning in this population.

To our knowledge, this is the first study to examine modifiable predictors of psychosocial functioning in a sample of individuals with schizophrenia and schizoaffective disorders and high negative symptom severity. We evaluated functioning in several different ways by using both performance-based and self-report measures of functioning, and our results implicated potentially useful treatment targets. In particular, motivation may be an important treatment target in both improving functional capacity and self-reported functioning in individuals with schizophrenia and high negative symptoms. Clinically, the findings of this study support the need for targeting different modifiable treatment targets based on individual needs. For example, if an individual has a global or specific cognitive skills deficit and shows functional impairment, they may benefit from treatments such as cognitive training or skills training in order to enhance their abilities. Importantly, global cognitive scores may not capture the unique heterogeneity of cognitive profiles in schizophrenia, so special attention should be paid to those with specific cognitive deficits (e.g., executive functioning deficits, verbal skills deficits) who may or may not benefit from cognitive remediation. However, if an individual possesses these cognitive skills but is not displaying functional improvement, cognitive behavioral therapy or other motivational interventions that target beliefs and motivation may help them to use the skills they already possess.

Acknowledgment

This work was funded by the National Institute of Mental Health of the National Institutes of Health (R34 MH101250; T32 MH019934), which had no other role in this publication. We are grateful to the participants in this study. Dr. Twamley also gratefully acknowledges the support of a VA Rehabilitation Research and Development Research Career Scientist Award.

Footnotes

Declarations of competing interest

Dr. Granholm has an equity interest in Granholm Consulting, Inc., a company that may potentially benefit from the research results as he receives income from the company for CBSST workshops and consulting. The terms of this arrangement have been reviewed and approved by the University of California, San Diego in accordance with its conflict of interest policies. The other authors declare no conflicts of interest.

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