Table 1.
Characteristics of included studies
| SINGLE CASE STUDIES | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Year author | Aim of study | N | Diagnosis | Age | Setting | Mode of delivery | No. of sessions | Intensity | Results |
| 2005 Davies & Tchanturia | To illustrate how CRT can be used to stimulate mental activities and improve thinking skills. | 1 | AN | 21 | Inpatients | Individual | 10 | Two 3 weekly sessions + 2 twice weekly | Improvement in cognitive set-shifting. |
| 2006 Tchanturia et al. | To demonstrate the potential benefits of CRT through a case-report. | 1 | AN | 42 | Inpatients | Individual | 10 | Once or twice weekly | The authors propose cognitive flexibility training as a pre-treatment intervention for treatment resistant inpatient cases. |
| 2007 Pretorius & Tchanturia | To demonstrate how CRT has been adapted for AN through a case-report. | 1 | AN | 31 | Inpatients | Individual | 10 | Twice weekly | Increase in BMI, tasks were a bit repetitive but the patient was able to develop new flexible strategies for implementation in real-life settings. |
| CASE SERIES | |||||||||
| Year author | Aim of study | N | Diagnosis | Age range (Mean) | Setting | Mode of delivery | No. of sessions | Intensity | Results |
| 2007 Tchanturia et al. | Explore the effect of CRT in set-shifting and investigates in acceptability for AN patients. | 4 | AN | 21-42 | Inpatients | Individual | 10 | Not reported | Improved cognitive flexibility and positive feedback for CRT. |
| 2008 Whitney et al. | To examine patients’ experience of participating in CRT. | 21 | AN | 17-54 (30.3) | Inpatients | Individual | 10 | Once or twice weekly | Positive that the intervention did not focus on food, helpful in reducing perfectionism and rigidity. More difficulty in tasks wanted, and help to implement newly learned skills. |
| 2008 Tchanturia et al. | To explore neuropsychological task performance before and after CRT. | 27 | AN | (28.8) | Inpatients | Individual | 10 | Twice weekly | Improvements in cognitive performance on the Brixton & CatBat tasks. No sign improvements in other neuropsychological tasks. Significant decrease in depression. |
| 2010 Genders & Tchanturia | To report CRT development and acceptability in a group format (2 male participants). | 30 | AN | 14-62 | Inpatients + Outpatients | Group | 4 | Once weekly | Statistically significant gains in self-reports of ability to change. CRT was found to be acceptable, useful and positive by both patient and group facilitators. |
| 2010 Pitt et al. | To evaluate the benefit of CRT in terms of changes in self-reported perfectionism and patient feedback. | 7 | AN + Recovered AN | (29.5) | Outpatients | Individual | 10 | Once or twice weekly | Initially confusing but mentally stimulating. Increased awareness of ones own thinking style. Both higher and lower degrees of perfectionism post CRT. |
| 2011 Wood et al. | To describe group CRT for adolescents. | 9 | AN | 13-19 | Inpatients | Group | 10 | Once and twice weekly | Patients found CRT fun and playful, helped develop a positive therapeutic relationship. Negative feedback involved tasks being boring, too easy tasks, repetitive, some negative group dynamics affected the group work. |
| 2011 Easter & Tchanturia | To examine how CRT has been implemented in the daily life of the patients through therapist feedback letters. | 26 | AN | Adults | Inpatients | Not reported | 10 | Twice weekly | Feedback letters were positive and motivational, and highlighted challenges in metacognitive ability and in transferring in therapy skills to every day life for the patients. |
| 2012 Abbate-Daga et al. | To measure the effect of CRT on cognitive flexibility. | 20 | AN | (22.5) | Outpatients | Individual | 10 | Once weekly | Improved neuropsychological performance. Significant improvement on impulse regulation, interoceptive awareness reflexive skills and awareness. |
| 2012 Pretorius et al. | Evaluation of group CRT for adolescents with AN through self-reported flexibility and motivation. | 30 | AN + EDNOS | 12-17 (15.6) | Outpatients | Group | 4 | Once weekly | No significant changes in flexibility and motivation to get better. Patient feedback: “interesting”, “fun”, “not too demanding”, “helpful”, but also “dull” and “repetitive”. Patients wanted more variation in exercises. |
| 2013 Zuchova et al. | To explore the feasibility and acceptability of group CRT for inpatients with AN. | 34 | AN | 18-45 | Inpatients | Group | 10 | Once a week | Group-based CRT could be well incorporated into the therapeutic program at the eating disorders unit, and was well received by the participants. |
| 2013 Dahlgren et al. (a) | To assess the feasibility of CRT for children and adolescents with AN. | 20 | AN | 13-18 (15.9) | Inpatients + Outpatients | Individual | 7-12 | Once or twice weekly | Results indicate feasibility for young patients with AN with regards to recruitment, materials, individual tailoring and delivery, and clinician feasibility. |
| 2013 Dahlgren et al. (b) | To assess neuropsychological functioning pre and post CRT. | 20 | AN | 13-18 (15.9) | Inpatients + Outpatients | Individual | 7-12 | Once or twice weekly | Significant changes in weight, depression, visio-spatial memory, global information processing and verbal fluency. Changes in weight had a significant effect on improvements in visio-spatial memory and verbal fluency. |
| 2013 Dahlgren et al. (c) | To explore self-reports and parental ratings of executive function before and after CRT. | 17 | AN | 13-18 (15.9) | Inpatients + Outpatients | Individual | 7-12 | Once or twice weekly | Decrease in patient BRIEF shift subscale post CRT. Parent reports revealed significant lower scores on shift-, emotional control- and working memory subscales, and on two composite indices. |
| 2013 Lask & Roberts | To assess feasibility of CRT in family settings. | 4 | AN | 14-19 | Inpatients + Outpatients | Family | 01/06/14 | Varying from weekly to monthly | CRT is useful when applied in families, and authors suggest a subsequent formal evaluation of this mode of delivery. |
| RANDOMISED CONTROLLED TRIALS | |||||||||
| Year author | Aim of study | N | Diagnosis | Age range (Mean) | Setting | Mode of delivery | No. of sessions | Intensity | Results |
| 2013 Lock et al. | To evaluate the feasibility of using CRT to reduce attrition in RCT’s for AN. | 23*/23 | AN | (22.7s) | Outpatients | Individual | 8 | 8 sessions during 2 months | CRT is acceptable and feasible for use in RCTs. It may also reduce short-term attrition. |
| 2013 Brockmeyer et al. | To investigate feasibility and efficacy of specifically tailored CRT, compared to NNT. | 11*/14 | AN | (23.6*/26.7) | Inpatients + Outpatients | Computer assisted & Individual | 30 | 30 sessions over 3 weeks | Participants receiving CRT outperformed participants in the NNT condition in cognitive set-shifting. Both groups showed high treatment acceptance. |
| 2013 Steinglass et al. | To evaluate AN-EXRP as an adjunctive strategy to improve eating behaviour during weight restoration. | 15*/15 | AN | 16-45 | Inpatients | Individual & Group | 12 | 3 times a week over 4 weeks | AN-EXRP is associated with better caloric intake than CRT when assessed through laboratory meals. |
| 2013 Dingemans et al. | To investigate the effectiveness of CRT in a randomised controlled trial comparing treatment as usual (TAU) and TAU plus CRT. | 41*/41 | ED | 17-53 | Mainly inpatients | Individual | 10 | 10 sessions over 6 weeks | CRT plus TAU was superior in terms of ED-related quality of life and ED psychopathology. CRT appears to be promising in enhancing effectiveness of concurrent treatment. |
Note. Results are presented descriptively due large discrepancies between studies, and for some papers, due to the lack of quantitative data.
* = Interventions details (i.e. mode of delivery, session details, intensity and intervention materials) refer to the CRT arm only.
AN = Anorexia Nervosa; AN-EXRP = Exposure and Response prevention for AN; BMI = Body Max Index; CRT = Cognitive Remediation Therapy; ED = Eating Disorder; EDNOS = Eating Disorder Not Otherwise Specified; NNT = Non-specific Neurocognitive Training; RCT = Randomised Controlled Trial.