New findings reported in Bipolar Disorders show that youth with bipolar disorder (BD) do not exhibit a decline in cognitive function over time. However, those with persistently low cognitive functioning may have a greater symptom burden and impairment in other areas of function.1
Few studies have investigated trajectories of cognitive functioning in youth with BD, especially as related to mood and other measures of functioning. Clarifying whether such individuals experience cognitive improvement, decline, or stability during the transition to adulthood could potentially inform the development of novel treatments for this patient population.
Studies that have examined these links indicate that youth with BD exhibit worse performance on measures of cognitive function at various points compared with healthy controls. In earlier research, the current authors found specific cognitive flexibility deficits in youth with bipolar I/II who were part of the Course and Outcome of BP Youth (COBY) study compared with those with bipolar not otherwise specified. The researchers further observed deficits in attention and informational processing for emotionally valenced words in all BD subtypes vs healthy controls.
In the current research, they sought to expand on those results by “evaluating the longitudinal course of cognitive functioning and its relationship with the mood trajectory and psychosocial functioning in COBY youth using latent class growth analysis,” which has not previously been used to examine these variables in patients with BD, they wrote. Each of the 135 participants was evaluated 3 times over the course of 2.5 years with the Cambridge Neuropsychological Test Automated Battery. The Longitudinal Interval Follow-Up Evaluation was used to measure clinical and functional outcomes.
The analysis revealed 3 longitudinal patterns of cognitive functioning among participants:
- Class 1: persistently high (15.6%)
- Class 2: persistently moderate (60.74%)
- Class 3: Persistently low (23.7%)
In comparison with normative data for the Cambridge Neuropsychological Test Automated Battery, all 3 classes demonstrated normal cognitive functioning across each follow-up point. However, after adjustment for confounders, the class 3 participants showed a greater prevalence of attention deficit/hyperactivity disorder and more total time with manic, depressive, overall, and syndromal symptoms compared with the other groups. Class 3 youth also scored worse on measures of global, social, and academic functioning compared with class 1 participants.
These findings “suggest that [bipolar] youth do not experience a cognitive worsening over time, and, preliminarily, do not support the ‘hypotheses of progression,’ ” according to the authors. Additional, larger studies are needed to confirm these conclusions. The results also indicate that bipolar youth with persistently low cognitive functioning “may benefit from cognitive remediation and early management with evidence-based pharmacological treatments.”
- Frías Á, Dickstein DP, Merranko J, et al. Longitudinal cognitive trajectories and associated clinical variables in youth with bipolar disorder [published online June 27, 2017]. Bipolar Disord. doi: 10.1111/bdi.12510
- Dickstein DP, Axelson D, Weissman AB, et al. Cognitive flexibility and performance in children and adolescents with threshold and sub-threshold bipolar disorder [published online October 5, 2015]. Eur Child Adolesc Psychiatry. doi: 10.1007/s00787-015-0769-2