Neurocognitive functioning in early‐onset and late‐onset older patients with euthymic bipolar disorder

Abstract

Most neurocognitive studies have not taken into account the fact that older patients with bipolar disorder (BD) are a heterogeneous population. The main goal of this study was to compare neurocognitive performance and extrapyramidal symptoms in older patients with early-onset BD (EO-BD) and late-onset BD (LO-BD). Euthymic older patients with EO-BD (n = 20), LO-BD (n = 20), and healthy controls (n = 20) were evaluated with traditional clinical instruments and measures of exposure to psychotropic drugs, as well as extrapyramidal symptoms. All subjects completed an extensive neuropsychological battery. Patients with EO-BD showed poorer performance than healthy controls in two measures of verbal memory and two measures of executive functions, whereas patients with LO-BD exhibited lower performance scores than healthy controls in almost all of the measures assessed. Impairments in the LO-BD group included even neurocognitive domains typically spared in mixed-age patients. Additionally, there was a trend toward displaying higher extrapyramidal symptoms in the LO-BD group compared with both EO-BD and healthy control groups. In both patient groups, psychosocial functioning was related with executive dysfunction and extrapyramidal symptoms. Patients with LO-BD may have more extensive and severe cognitive impairments, as well as higher vulnerability to extrapyramidal symptoms, compared with patients with EO-BD. Cognitive-motor disturbances may help to explain impairments in daily functioning among older patients with EO-BD and LO-BD during remission.