Patients with lifetime psychosis, subthreshold depressive symptoms, and poor cognitive performance are less likely to achieve functional recovery in bipolar disorder (BD), according to study results published in the Journal of Clinical Medicine.
Investigators recruited 420 euthymic patients with BD from the BD and Depression Unit at the Hospital Clinic of Barcelona, Spain. Investigators interviewed all patients and performed functional assessments and comprehensive neuropsychological evaluations. Patients were then stratified into two groups: functionally remitted (n=221) and functionally impaired (n=199). Based on Functioning Assessment Short Test scores, group 1 included patients with mild or no impairment (scores ≤20), and group 2 included patients with moderate and severe impairment (scores between 21 and 72).
To identify demographic, clinical, and neuropsychological factors associated with functional remission, investigators performed descriptive analyses using chi-square tests for categorical variables, with continuous variable comparison conducted using student t tests. Effects of the risk factors associated with functional impairment were calculated using logistic regression.
Analyses revealed that a lifetime history of psychotic symptoms best predicted functional recovery (odds ratio [OR], 2.91; 95% CI, 1.11-7.54), followed by the presence of subthreshold depressive symptoms (OR, 1.48; 95% CI, 1.29-1.70). In addition, executive functions and verbal memory were significant barriers to achieving good functional adjustment, as shown in the following variables: working memory IQ (OR, 0.95; 95% CI, 0.93-0.98), Wisconsin Card Sorting Test number of categories (OR, 0.7; 95% CI, 0.50-0.98), and California Verbal Learning Test short-cued recall (OR, 0.68; 95% CI, 0.49-0.93).
Due to the study’s cross-sectional nature, investigators could not establish causal relationships between independent and dependent variables. In addition, pharmacotherapy was not controlled for.
“[Treatments] to ensure a good functional outcome in BD should specially prevent psychosis, target subthreshold depressive symptoms and enhance cognition, more specifically executive functions and verbal memory,” investigators wrote.
“Future longitudinal studies are needed in order to confirm the present results,” investigators wrote. “Moreover, including the assessment of genetics and neuroimaging of these two groups (functionally remitted [vs] impaired) might help us to better understand the biological underpinnings that could occur under these two phenotypically distinct groups,” they added.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Bonnín CM, Jiménez E, Solé B, et al. Lifetime psychotic symptoms, subthreshold depression and cognitive impairment as barriers to functional recovery in patients with bipolar disorder [published online July 18, 2019]. J Clin Med. doi:10.3390/jcm8071046