Variables associated with performance on a cognitive screening measure and cognitive remediation training outcome in the acute phase of Major Depressive Disorder

Abstract

Major Depressive Disorder (MDD) is associated with cognitive deficits, particularly in the domains of attention, memory, and executive functioning (EF). Previous research has demonstrated that residual cognitive deficits secondary to depressive disorders are associated with risk of relapse. Established treatments for depression, such as cognitive behavioural therapy (CBT) and psychotropic medications, have been shown to improve cognition in MDD. More recently, cognitive remediation therapy has been associated with improvement of cognitive deficits in depression. This project consisted of two studies which sought to investigate the relationship between several clinical variables and (a) cognitive functioning, and (b) changes in cognitive functioning following cognitive remediation training in the acute phase of major depressive disorder. Study 1 used a retrospective study method and made use of a secondary database from a tertiary-care outpatient clinic. The purpose was to investigate the relationship between two variables (number of past depressive episodes and past hospitalization due to depression) and attention, memory, and executive functioning scores on a cognitive screening battery, in 125 individuals with acute depression, while controlling for psychiatric medication use. These two variables were unrelated to cognitive performance, after controlling for use of psychotropic medications. Study 2 was an exploratory pre-post community-based pilot study with 12 individuals with acute depression that examined the association of three clinical variables (number of comorbidities, severity of depression, and perceived cognitive deficit) with changes in memory, attention, and reasoning performance following an 8 weeks of CRT with six sessions per week. Participants completed 44.67 sessions (93.06%) with a range of 29 to 48 and showed improvement in memory scores. In univariate, but not multivariate models, comorbidity and depression severity were positively associated with reasoning and memory score increases. Findings are discussed within the context of the strengths and limitations of the studies. Keywords: depression, cognitive functioning, cognitive remediation training