Cognitive remediation training may improve outcomes in patients with partially remitted unipolar depression, according to research published in the Journal of Affective Disorders. Results indicate that cognitive training, undertaken early in the disease, may be beneficial for some patients.

Researchers conducted a single-blinded, randomized, controlled clinical trial to evaluate the ability of cognitive remediation therapy to improve outcomes in patients with partially remitted unipolar depression. Researchers claim that this study is the first of its kind to examine cognitive remediation improvement factors in this type of population sample.

Patients with major depressive disorder and cognitive deficits were recruited between April 2013 and August 2017. Fifty-seven participants (42 women; mean age 45.39±12.118 years; age range 19-60 years) met the inclusion criteria, including (partial) remission measured as a Hamilton Rating Scale for Depression (HAM-D) score less than 20, aged 18 to 60 years, history of major depressive disorder, an IQ greater than 80 as measured by the Multiple Choice Vocabulary Test, German fluency, and the presence of cognitive deficits determined by scores in at least 2 cognitive tests.

Study participants were assessed at baseline and were randomly assigned to 1 of 3 groups: individualized training, generalized training, and no training (passive control group). Both training groups received cognitive remediation therapy in the form of 12 sessions, and all participants received both medical and psychotherapeutic treatment as usual. All participants were re-evaluated between 5 and 7 weeks after the baseline assessment.

At baseline, no differences were noted between the training and control groups in terms of demographic, clinical, neuropsychological, and psychosocial characteristics, although baseline HAM-D scores were significantly different in the training and control groups.

Participants in the training groups reported high motivation through all training sessions. Exhaustion reported before and after training was 43.51% and 55.92%, respectively, with higher exhaustion in the individualized training vs generalized training groups (45.47% vs 42.03% and 56.92% vs 55.27%). Fun and joy experienced in training sessions were reported as 64.59%, and average exertion at session completion was 56.99%.

Investigators then followed the reliable change indices of attention tests within the sample of 38 training participants (29 women; age 45.63±13.048 years) and identified 13 patients who were categorized as improvers. This sample was subdivided into improvers and nonimprovers (n=25), who were compared based on sociodemographic, psychopathological, neurocognitive, psychosocial, and training factors. No significant differences between improvers and nonimprovers were noted in terms of age, gender, education level, employment, relationship status, or housing situation.

Nonimprovers did experience a significantly longer illness duration (15.881±13.496 years) compared with improvers (4.625±3.926 years), with a trend in the difference of Childhood Trauma Questionnaire sum scores. Improvers generally experienced less childhood trauma compared with nonimprovers.

No significant between-group differences were noted in terms of the number of past depressive episodes, hospitalizations, current or ever psychotherapy status, remission status, Beck Depression Inventory-II and HAM-D baseline and post-treatment scores, and Temporal Experience of Pleasure Scale sum scores. In terms of both neurocognitive and psychosocial factors, there were no significant differences in any measures between the improver and nonimprover groups.

Finally, investigators compared training motivation at baseline between groups. Overall, improvers reported less probability of failure (means=13.154±6.189) compared with nonimprovers (means=17.625±7.119). Neither did the groups differ significantly in terms of motivation during cognitive training, exhaustion before and after training, fun and joy experienced in each training session, or average exertion on session completion.

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Study limitations include the small sample size, the exploratory nature of the analyses, and an inability to analyze other possibly important key variables such as work habits and treatment intensity.

“Our findings represent a first analysis of possible predictors of cognitive remediation training improvement in (partial) remitted unipolar depression,” the researchers concluded. “Much more work should be done to refine cognitive treatment approaches,” they added, indicating that more clinical trials utilizing different training designs, intensity, and frequency should be undertaken.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Listunova L, Bartolovic M, Kienzle J, et al. Predictors of cognitive remediation therapy improvement in (partially) remitted unipolar depression. J Affect Dis. 2019;264:40-49.