Two-year follow-up of treated adolescents with early-onset bipolar disorder: Changes in neurocognition

Abstract

Background: Few studies have analyzed the course of neurocognition in treated children and adolescents with early-onset bipolar disorder (EOBD) and shown improvements in attention, working memory, and verbal memory after treatment. The aim of this study was to determine the progress over two years in neuropsychological performance of a sample of medicated adolescents with EOBD compared to healthy controls (HC).

Methods: Twenty adolescents, diagnosed in clinical setting as DSM-IV bipolar disorder, treated for two years, euthymic, and 20 gender and age-matched HC were assessed at two moments in reasoning, verbal and visual memory, working memory, speed, visual-motor skills and executive function. Multivariate analyses of variance was carried out to analyze the differences between groups over time, and to monitor the influence of psychotic symptoms and type of mood-stabilizer.

Results: The entire sample improved on verbal and visual memory tests (verbal recall p<0.01; visual recall p<0.001). Moreover, patients improved more than controls in verbal reasoning (p<0.01), working memory (p<0.01), processing speed (p<0.01) and visual-motor skills (p<0.001). Psychotic symptoms and treatment with lithium were associated with poorer development in executive control tasks.

Limitations: Sample size was small and groups were re-evaluated in slight different follow-up periods. Doses of antipsychotics drugs over time were not controlled.

Conclusions: Processing speed and visual-motor skills in the EOBD group normalized during follow-up. Executive functioning, working memory, and verbal and visual memory remained impaired in patients versus controls. The knowledge of cognitive deficits due to normal course of illness or to drug effects allows better therapeutic strategies.

Keywords: Adolescent; Bipolar disorder; Cognition; Control group; Follow-up study.