Abstract
Introduction: Individuals hospitalized with depression are particularly impacted by cognitive impairment. Identifying variables that predict improvements in cognition across treatment may inform more targeted and effective treatment approaches. We conducted secondary analyses to investigate baseline predictors of objective cognitive change in a severely depressed inpatient sample.
Methods: A randomized controlled trial (RCT) comparing 2 weeks of Activation Therapy (AT; Cognitive Activation combined with Behavioural Activation) with treatment-as-usual (TAU) was conducted in inpatients with major depression. Research assessments were conducted at baseline (on admission) and at 14 weeks (12 weeks after treatment-end). A series of analyses of covariance models were conducted to examine associations between change in executive functioning/attention, verbal learning and memory, visuospatial learning and memory, and psychomotor speed, in global cognition, and a range of putative baseline predictor variables (e.g., demographic, mood, cognition, general functioning, childhood trauma) across the whole RCT sample. Treatment arm was included as a fixed factor in all models. Sensitivity analyses were run in the AT group only to examine predictors of cognitive change in those receiving this targeted cognitive treatment.
Results: Sixty-eight individuals completed baseline and follow-up cognitive testing assessments in the RCT (AT, n = 32, TAU, n = 36). Significantly poorer domain-specific baseline cognitive functioning was associated with greater cognitive improvement in all four domains. Older age was associated with less cognitive change in verbal learning and memory, visuospatial learning and memory, psychomotor speed, and global cognition. Sensitivity analyses (AT group only) identified these same factors as significant predictors.
Conclusion: Age and domain-specific baseline cognitive performance were consistently associated with cognitive change in this RCT. Findings suggest that cognition seems to recover better in younger inpatients with poorer baseline cognitive functioning.
Clinical registration: Australian New Zealand Clinical Trials Registry [ANZCTR], ACTRN12617000024347p.