Performance-based measures of functional capacity correlated with objective cognitive outcomes in patients with bipolar disorder, according to study data published in the Journal of Affective Disorders. In a clinical trial setting, these performance-based measures may have utility in determining whether treatment-related improvements in cognition translate to increased functional capacity.
Investigators abstracted baseline data from 2 ongoing clinical trials of cognition in bipolar disorder. Patients in each trial were in full or partial remission from bipolar disorder and presented with cognitive impairment. At baseline, patients were administered a series of neuropsychological tests to assess objective cognitive function.
Subjective cognitive function was then assessed per 3 distinct measures: performance-based, interview-based, and self-reported. Performance-based functional capacity was assessed with the UCSD Performance-Based Skills Assessment-Brief; interviewer-rated functional capacity with the Functional Assessment Short Test; and self-reported functional capacity with the Work and Social Adjustment Scale and the Sheehan Disability Scale. The same battery of tests was administered to a cohort of healthy control individuals without bipolar disorder or cognitive impairment. Correlation analyses were performed to identify associations between objective and subjective cognition and measures of functional capacity. Multiple regression analyses were conducted to identify which correlations remained significant after adjustments for clinical and demographic factors.
Data from 58 patients and 37 healthy control individuals were pooled for analyses. Demographic characteristics were largely comparable between the patient and control cohorts. Patients with bipolar disorder presented with significantly greater impairment in global cognitive score compared with control individuals (P =.03). Patients with bipolar disorder also reported more subjective cognitive complaints and lower interview-based functional capacity than control individuals (both P <.01). Objective global cognition was directly correlated with performance-based functional capacity, even after adjustments for patient age, sex, verbal intelligence quotient, and mood symptoms (P <.01). In contrast, interview-based and self-reported measures of functional capacity were not directly associated with objectively-measured cognition.
The study was limited by its cross-sectional design and small sample size.
From these data, investigators concluded that a performance-based measure of functional capacity may be the most effective means of assessing cognition improvements in clinical trials of patients with mood disorders. Additional research is necessary to elucidate the utility of subjective cognition measures in clinical practice.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Ott C, Miné H, Petersen JZ, Miskowiak K. Relation between functional and cognitive impairments in remitted patients with bipolar disorder and suggestions for trials targeting cognition: an exploratory study. J Affect Disord. 2019;257:382-389.