Investigating the Efficacy of a Top-Down Approach to Cognitive Remediation in Individuals With Affective Disorders
Investigating the Efficacy of a Top-Down Approach to Cognitive Remediation in Individuals With Affective Disorders
Individuals with affective disorders (including post-traumatic stress disorder (PTSD) and major depressive disorder (MDD)) often experience declines in cognitive abilities such as memory and attention. Such difficulties can reduce functioning in important aspects of life, including at work or school. Little research has been conducted to investigate if cognitive dysfunction can be reduced in individuals with PTSD or MDD following a specific treatment. Thus, the investigators plan to determine the utility of a cognitive training program called goal management training (GMT) in reducing cognitive dysfunction in MDD/PTSD. GMT aims to assist participants in building skills in performing specific behaviours that rely on basic cognitive processes, allowing them to achieve an identified goal. 64 individuals with PTSD and 64 with MDD will be divided into two groups of 32, one GMT group, and one wait-list group that will receive GMT after study completion. The investigators predict that in comparison to the wait-list group, the GMT group will show greater improvements in cognitive functioning and everyday functioning following treatment and that these improvements will remain long-term.
In addition to their core affective components, MDD and PTSD are associated with poor cognitive functioning across a host of highly similar domains, including declarative memory, short-term memory, attention, and executive functioning. These deficits have been associated with reduced response to pharmacological and non-pharmacological interventions and poor functional outcomes. Given the potentially devastating impact of poor cognitive functioning on the ability of patients with affective disorders to benefit from treatment interventions, and its association with poor functional outcomes, there is an urgent need to identify novel treatment interventions aimed at reducing cognitive dysfunction in these disorders. Accordingly, the aim of the present proposal is to a randomized controlled trial examining the efficacy of a well-established cognitive intervention aimed at reducing attentional and executive dysfunction, Goal Management Training® (GMT), in the treatment of cognitive deficits among patients with MDD and with PTSD. A secondary aim is to determine the longer-term impact of this approach on functional outcomes.
Importantly, limited investigation of cognitive remediation therapy has been performed in these populations. Only one study has been conducted to examine the impact of a non-standardized intervention protocol aimed at improving cognitive functioning in PTSD. Here, clinically (but not statistically) significant improvements were noted in a small pilot study on measures of cognitive functioning after employing bottom-up executive training approach in conjunction with transcranial direct current sample of four patients. Previously, the investigators have applied computer-assisted cognitive remediation, a bottom-up restitution based approach, in patients with MDD, resulting in improvements in performance on working memory tasks in conjunction with increased functional activity in lateral prefrontal and parietal areas, however, the broad benefits of this training observed in a small sample (n=12) did not generalize to a larger group.
GMT has demonstrated efficacy in several clinical and non-clinical populations that experience deficits in executive functioning, attention, and memory (similar to those seen in MDD and PTSD), including older adults, individuals who have suffered a traumatic brain injury, have attention-deficit hyperactivity disorder (ADHD), poly-substance abuse disorder, or spina bifida. In these studies, participants showed improvements in completing every-day tasks (as measured by self-report), as well as improvements in executive functions such as decision-making, working memory and selective attention. Critically, these results were maintained at follow-up (when assessed). Given the previous success of this intervention in remediating frontal-temporally mediated brain dysfunction across clinical populations, the investigators hypothesize that GMT has the ability to target similar cognitive difficulties experienced by those suffering from MDD and from PTSD. The investigators will further examine whether putative improvements in cognitive performance will translate to functional improvements analogous to those seen in other psychiatric populations undergoing cognitive remediation.
In the current study, the investigators will conduct the first study to investigate the utility of GMT in patients with MDD or with PTSD. Specifically, the primary aim of this proposed study is to examine whether a standardized 9-week program of GMT results in durable improvements in cognitive functioning relative to a wait-list control (WLC). A secondary aim will be to determine whether participation in the GMT group is associated with long-term functional improvements. The investigators hypothesize that at post-treatment, participants with MDD and with PTSD assigned to the GMT groups will show significantly greater improvement in neuropsychological test performance and greater functional improvement compared to participants in the WLC group; these gains are expected to be maintained at 3 month follow-up.
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