Long-term outcomes of an internet-delivered cognitive enhancement intervention targeting residual cognitive deficits after major depressive disorder: a 2-year follow-up of an open trial.

Background: Cognitive deficits are common and disabling residual symptoms following major depressive disorder (MDD) and are related to increased risk of relapse. Residual cognitive deficits should thus be considered an important target for treatment. However, few have reported long-term outcomes of interventions targeting residual cognitive deficits. Objective: This study aimed to (1) investigate change between pre-treatment and 2-year follow-up assessments in cognitive deficits, rumination, and symptoms of MDD after an internet-delivered intervention targeting residual cognitive deficits; (2) to investigate stability in outcomes between 6-month and 2-year follow-up assessments; (3) to report the number of participants' experiencing a new episode of MDD in the follow-up period; and (4) to investigate differences in outcomes between those who experienced a new episode of MDD and those who did not. Methods: A total of 43 partly remitted adults were included to test a guided internet-delivered intervention, which consisted of 10 modules involving psychoeducation, cognitive strategies, and attention training. Participants were assessed at pre-treatment, post-treatment, after 6-months, and after 2-years, with measures assessing self-reported residual cognitive deficits, rumination, symptoms of MDD and relapse. Overall, 32 participants completed the 2-year follow-up assessment. Results: Between the pre-treatment and 2-year follow-up assessments, there was a reduction in cognitive deficits and rumination, while there was an increase in symptoms of MDD. Cognitive deficits were stable between the 6-month and the 2-year follow-up, while there was an increase in rumination and symptoms of MDD. Thirteen of 32 participants reported a new episode of MDD during the follow-up period. The relapse group reported longer duration of MDD at pre-treatment and showed a difference in all outcomes after 2 years compared to the no-relapse group. The no-relapse group showed improvement in MDD symptoms at post-treatment, while the relapse group did not. Conclusion: Delivering cognitive enhancement interventions over the internet is potentially related to stable improvements in residual cognitive deficits. The effects on rumination and symptoms of MDD are less certain. Lack of improvement in MDD symptoms after the intervention period should be investigated as an indicator of relapse. Results should be interpreted with caution due to the lack of control group and sample size.

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.

Predictors of Treatment Response to an Internet-Delivered Intervention Targeting Residual Cognitive Symptoms After Major Depressive Disorder.

Objective: Residual cognitive symptoms after depression are common and associated with reduced daily life functioning and an increased risk of depression relapse. There is a lack of knowledge on treatments targeting residual cognitive symptoms after major depressive disorder (MDD), including the factors associated with treatment response. The aim of the current study is to explore factors of treatment response to a guided internet-delivered intervention for former depressed adults experiencing residual cognitive symptoms. Method: Forty-three former depressed adults with residual cognitive symptoms were included. Linear mixed model analyses were used to investigate the impact of pre-treatment demographic-, illness, and symptom variables, and therapy process variables, such as credibility, expectancy, and user behavior, on reduction in residual cognitive symptoms from pre-treatment to 6-month follow-up. Results: Having had MDD for a year or less predicted more reductions in residual cognitive symptoms from pre- to 6-month follow-up. Higher levels of perceived treatment credibility and expectancy evaluated in the early course of treatment did also predict a positive treatment response. No demographic-, symptom-variables, previous number of episodes with MDD, and user behavior were associated with change in residual cognitive symptoms. Conclusion: This study suggests that individuals with shorter duration of previous depressions might have larger reductions in residual cognitive symptoms at 6-month follow-up compared to those with a longer duration of depression. Treatment credibility and expectancy also predicted treatment response and effort should also be made to ensure interventions credibility. Results should be interpreted with caution due to the study having a low sample size. Further investigation of predictors should be conducted in a full scale randomized controlled trial.

Developing an internet-delivered intervention targeting residual cognitive symptoms after major depressive disorder: a person-based approach.

BACKGROUND: Cognitive difficulties are rarely addressed after the treatment of major depressive disorder (MDD). New scalable treatments are needed. To ensure relevance and engagement of novel interventions, there is a need to understand the perspectives of the users. AIM: Explore former depressed adults needs and perspectives during the planning and development of a novel internet-delivered intervention targeting residual cognitive symptoms after MDD. METHOD: The planning phase included exploratory qualitative interviews with former depressed adults (n = 16). In the development phase, a prototype including psychoeducation, attention training and compensatory strategies was tested in think-aloud interviews with former depressed adults (n = 7) and psychologists (n = 4). Data were analysed thematically. RESULTS: Analysis of exploratory interviews identified four themes. Experiences of residual cognitive symptoms consisted of two sub-themes (Everyday life is more demanding; Concerns about cognitive difficulties). Coping with residual cognitive symptoms had two sub-themes (Compensatory strategies; Acceptance). Needs from an intervention consisted of two-subthemes (Need for information; Therapist support). Barriers for engagement consisted of three sub-themes (Being overwhelmed; Not being motivated; Frequent registration). Analysis of think-aloud interviews was organized into three themes: Positive perceptions of content; Concerns regarding content; Perceptions of Layout, Visuals and Navigation. CONCLUSION: The intervention may address concerns and consequences of cognitive difficulties by including psychoeducation, compensatory strategies and elements to increase acceptance and motivation, provided in manageable proportions.

An open pilot study of an internet-delivered intervention targeting self-perceived residual cognitive symptoms after major depressive disorder.

Residual cognitive symptoms are associated with reduced daily life functioning, quality of life and represent a risk factor for relapse of major depressive disorder (MDD). There are few studies targeting self-perceived residual cognitive symptoms after MDD. The current open pilot study examines clinical outcomes and feasibility of a novel internet-delivered cognitive enhancement treatment for mood disorders specifically tailored to target self-perceived residual cognitive symptoms after MDD. A total of 43 adults with self-perceived residual cognitive symptoms after MDD were included. Participants were assessed pre- and post-treatment and at 6-month follow-up. The intervention consists of 10 modules that includes psychoeducation, cognitive strategies, and attention training, coupled with weekly therapist guidance. Results showed a significant reduction from pre- to post-treatment in self-perceived residual cognitive symptoms (d = 0.98) and rumination (d = 0.63). Results remained significant at the 6-month follow-up (d = 1.06; d = 0.86). Reliable change in self-perceived residual cognitive symptoms were obtained in 60% of the participants from pre- to post-treatment. Completion rates (86%) and treatment satisfaction (97%) were high. This open pilot study supports that targeting self-perceived residual cognitive symptoms after MDD through internet-delivered cognitive enhancement therapy for mood disorders may be feasible and provide stable reductions in self-perceived residual cognitive symptoms and rumination.