Improved functioning following computerized working memory training (COGMED®) in euthymic patients with bipolar disorder and cognitive complaints: An exploratory study

Improvement in self-reported cognitive functioning but not in rumination following online working memory training in a two-year follow-up study of remitted major depressive disorder

Self-reported subjective cognitive difficulties (subjective deficits) and rumination are central residual cognitive symptoms following major depressive disorder (MDD). These are risk factors for more a severe course of illness, and despite the considerable relapse risk of MDD, few interventions target the remitted phase, a high-risk period for developing new episodes. Online distribution of interventions could help close this gap. Computerized working memory training (CWMT) shows promising results, but findings are inconclusive regarding which symptoms improve following this intervention, and its long-term effects. This study reports results from a longitudinal open-label two-year follow-up pilot-study of self-reported cognitive residual symptoms following 25 sessions (40 min), five times a week of a digitally delivered CWMT intervention. Ten of 29 patients remitted from MDD completed two-year follow-up assessment. Significant large improvements in self-reported cognitive functioning on the behavior rating inventory of executive function-adult version appeared after two-years (d = 0.98), but no significant improvements were found in rumination (d < 0.308) measured by the ruminative responses scale. The former showed moderate non-significant associations to improvement in CWMT both post-intervention (r = 0.575) and at two-year follow-up (r = 0.308). Strengths in the study included a comprehensive intervention and long follow-up time. Limitations were small sample and no control group. No significant differences between completers and drop-outs were found, however, attrition effects cannot be ruled out and demand characteristics could influence findings. Results suggested lasting improvements in self-reported cognitive functioning following online CWMT. Controlled studies with larger samples should replicate these promising preliminary findings.

Does cognitive improvement translate into functional changes? Exploring the transfer mechanisms of cognitive remediation therapy for euthymic people with bipolar disorder

BACKGROUND

Bipolar disorder (BD) is associated with cognitive and functional difficulties, persistent beyond mood episodes. Cognitive remediation (CR) is a psychological therapy targeting cognitive and functioning difficulties. Recent evidence suggests that CR may enhance long-term functioning but transfer mechanisms on functional outcomes have not been explored. We aim to investigate whether and how cognitive gains after CR transfer to functional improvement.

METHODS

We considered data from a randomized controlled trial comparing CR (n = 40) to treatment-as-usual (TAU; n = 40) in euthymic people with BD. Treatment outcomes included individual cognitive domains and global cognition, psychosocial functioning, and goal attainment. Regression-based mediation and moderation modelling were used to assess whether and how post-treatment cognitive changes translate into functional improvement at follow-up, three months after treatment end.

RESULTS

Cognitive gains after CR transferred to functional changes three months later: improvement in post-treatment global cognition partially mediated the effect of CR on psychosocial functioning (standardized indirect effect: -0.23, 95% CI -0.51 to -0.04). Goal attainment was not significantly mediated by changes in cognition, but post-treatment cognitive performance moderated the effect of CR on the GAS at follow-up (interaction effect: 0.78, 95% CI 0.08-1.55).

CONCLUSIONS

Our findings suggest that cognitive improvements contribute to functional improvement but transfer mechanisms differ between psychosocial functioning and idiosyncratic recovery goals. Cognition accounted for only a proportion of the total CR effect on functional outcomes. Future studies should consider other variables, such as metacognition, that may drive the transfer of CR effects to functional outcomes.

Effects of virtual reality working memory training on event-based prospective memory in patients with major depressive disorder

BACKGROUND

Event-based prospective memory (EBPM) refers to remembering to perform delayed intention when specific events occur. EBPM deficit is present in patients with major depressive disorder (MDD) and hinders recovery from the illness. Working memory training (WMT) has been reported to enhance EBPM but its effect on EBPM in MDD remains unclear. We investigated whether virtual reality (VR)-based WMT can improve EBPM in MDD patients.

METHODS

Forty-six MDD patients and 41 healthy controls (HC) were recruited. Among the former ones, the first 23 consecutive patients were allocated to the experimental group (MDD-VR) and the next 23 consecutive patients to the waitlist control group (MDD-W). EBPM accuracy was used to assess EBPM performance. Hamilton Depression Rating Scale (HDRS) and Massachusetts General Hospital Cognitive and Physical Functioning Questionnaire (CPFQ) were employed to assess the cognitive functions and the depressive symptoms.

RESULTS

At baseline, EBPM accuracy did not significantly differ between MDD-VR and MDD-W but was lower in both of these two groups than in HC (both p < 0.001). Group-by-time interactions on EBPM accuracy (F = 4.614, p = 0.031) and CPFQ score (F = 5.754, p = 0.021) were present, whereas no significant group-by-time interaction or group effects were observed for HDRS score (both p > 0.05). After VR intervention, MDD-VR showed an increase in EBPM accuracy (Cohen's d = 1.20 [95% CI: 0.53, 1.86], p = 0.001).

CONCLUSIONS

Our results demonstrated that VR-based WMT could improve EBPM deficits in MDD patients. Large-scale studies of a VR-based WMT program are indicated.

Computerized Working Memory Training in Remission From Major Depressive Disorder: Effects on Emotional Working Memory, Processing Speed, Executive Functions, and Associations With Symptoms

Introduction

Remission from major depressive disorder (MDD) is associated with residual symptoms related to reduced functioning, quality of life, and relapse risk. Previous studies have raised questions about mechanisms involved-in and affected by cognitive training. This study investigated the associations and changes among depressive symptoms, rumination, processing speed (PS), executive functioning (EF), and emotional working memory (e-WM) pre- post computerized working memory training (CWMT).

Method

Twenty-nine remitted participants were included in a pre- post pilot study of within-subject effects of online CWMT. A total of 20 participants completed the intervention and pre- post tests of EF and PS, e-WM, in addition to symptom and rumination measures. Associations between changes in symptoms and cognition were investigated pre- post. Associations between improvements in CWMT, depression history, and changes in cognition were explored. Hypotheses and statistics were preregistered before data were analyzed.

Results

Manipulation of negatively valanced stimuli in e-WM showed an inverse association with rumination pre-intervention, but the association disappeared post-intervention. Cognitive functioning improved in most conditions with largest effects in EF. Symptoms did not change in the remitted sample. CWMT improvements were related to improvements in some aspects of EF and PS, but also to worse self-reported attention. Depression history was related to less improvement in EF.

Limitations

Sample size was small and there was dropout from the study. There was no control group, thus precluding practice and placebo effects and causal relationships.

Conclusions

Computerized WM training improves cognitive functions and could influence associations between e-WM and rumination. This could counteract functional impairment following MDD.

Cognitive control training for children with anxiety and depression: A systematic review

Cognitive control training has gained traction as an intervention for reducing anxiety and depression vulnerability in adults. There are, however, a limited number of studies investigating such training interventions for reducing symptomology of anxiety and depression in children and adolescents. Thus, we aimed to provide a robust review and qualitative synthesis of the available research in young people. Twelve articles met the inclusion criteria, and all were randomised control trials. Evidence of the efficacy of cognitive control training for relief of symptoms are reported separately for anxiety, depression, and other related psychological factors, and on the basis of type of cognitive control training paradigm. A lack of standardisation in relation to type of intervention, duration and context, outcome measures and population was observed. Results are discussed in terms of these variations and recommendations for future research are provided.

Significant Association Between Huntingtin Gene Mutation and Prevalence of Hopelessness, Depression and Anxiety Symptoms

SUMMARY BACKGROUND

In Huntington's disease psychiatric symptoms may manifest prior to motor dysfunction. Such symptoms negatively impact people's quality of life and can worsen the course of the primary disease. The aim of the present study was to assess and compare depression, anxiety and hopelessness rates in individuals with and without an abnormal expansion of CAG repeats in the huntingtin (HTT) gene and healthy controls.

MATERIALS AND METHODS

Study involved 31 individuals referred for genetic testing for Huntington's disease and a control group of 41. Depressive and anxiety symptoms were assessed using Beck Hopelessness Scale (BHS) and Hospital Anxiety and Depression Scale (HADS). Results between groups were compared using the Mann-Whitney U test. Two-sided Bonferroni corrected p-value was set at ≤0.017.

RESULTS

Individuals with HTT gene mutation ("gene mutation positive", GMP) (N=20) scored higher on the HADS depression subscale (5.90 ± 4.52 vs 1.36 ± 1.91; p ≤ 0.017) than those without HTT gene mutation ("gene mutation negative", GMN) (N=11). GMP and control groups scored higher than the GMN group on the BHS (5.65 ± 3.91 vs 2.09 ± 1.64 and 5.27 ± 4.11 vs 2.09 ± 1.64, respectively; p ≤ 0.017). No differences in anxiety levels were found.

CONCLUSIONS

Depressive symptoms and hopelessness were more prevalent in individuals with HTT gene mutation than in individuals who were tested but had no said mutation. Such results emphasise the importance of timely diagnosis and treatment of psychiatric comorbidities in individuals affected by Huntington's disease.

A Preliminary Study on the Functional Benefits of Computerized Working Memory Training in Children With Pediatric Bipolar Disorder and Attention Deficit Hyperactivity Disorder

Twenty-nine pediatric patients (age range, 10–16 years) with working memory (WM) deficits, including children with pediatric bipolar disorder (PBD) with and without attention-deficit hyperactivity disorder (ADHD) comorbidity and children with ADHD, underwent a Cogmed WM training program. For both patient groups, WM performance on Cogmed tasks and on the Digit Span test improved significantly after training. Moreover, the PBD group improved on Trails Making Test A and on the Inhibition Scale, the Behavior Regulation Index, and the Global Executive Composite of the Behavioral Rating Inventory of Executive Function. The ADHD group improved significantly on the Trails Making Test B, the Spatial Span Test, and the Reading Fluency Test of the Woodcock–Johnson III, as well as on depressive symptoms. The present findings suggest that working memory training is beneficial not only in youths with ADHD but also in youths with PBD. They also show evidence of near and far transfer of WM improvement in these patients, although in different ways for the two patient groups. Future studies examining the mechanisms of cognitive remediation in pediatric patients will aid in creating tailored illness-specific cognitive interventions.