The Effects of Computerized Cognitive Behavior Therapy (cCBT) on Brain Health: A Feasibility Study

Among people with HIV, the severity of depressive symptoms has repeatedly been associated with the presence of self-reported cognitive difficulties, even in the absence of impairment on neuropsychological testing. There is uncertainty about the clinical importance of these self-reports, especially when neuropsychological testing is normal, as they are thought to be susceptible to patients' biases and insights into their illness.

However, there is growing evidence that these self-reports are clinically important. Among patients with major depressive disorder (MDD), evidence suggests that functional impairments is mediated by self-reported cognitive dysfunction, rather than objective cognitive dysfunction. For example, Buist-Bouwman et al reported that more than one-quarter of the impact of MDD on work loss was directly attributable to self-reported cognitive difficulties and that cognition was a significant mediator of the association between MDD and work or role dysfunction.

When depression is treated with antidepressant medication, some degree of improvement on neuropsychological tests has been documented. However, many studies have evaluated cognitive outcomes before and after treatment rather than comparing them with placebo, potentially biasing the results by learning effects, which limits the strength of the conclusions that can be drawn.

Treatment of depression with Cognitive-Behaviour Therapy (CBT) has been shown to improve depressive symptoms and psychosocial functioning in patients with recurrent major depressive disorder, but there are few studies of the impact of psychotherapy on self-reported cognition and cognitive performance. In a group of patients with highly recurrent depression (≥4 episodes) over 2 years of follow-up, Conradi et al showed that those randomized to receive psycho-education plus CBT reported the presence of cognitive symptoms significantly less of the time compared to those receiving psycho-education only (15% of the time or 3.6 months compared to 47% or 11.3 months).

In the HIV population, a single study has examined the effect of treatment of depression on self-reported cognitive difficulties and performance on neuropsychological tests, as part of a randomized controlled trial of antidepressant efficacy. Following 12 weeks of antidepressant treatment, HIV+ individuals who reported a decrease in depressive symptoms also reported significantly fewer cognitive difficulties, despite an absence of improvement on neuropsychological testing.