12-month longitudinal cognitive functioning in patients recently diagnosed with bipolar disorder.

OBJECTIVES: Although cognitive deficits are observed in the early stages of bipolar disorder, the longitudinal course of neuropsychological functioning during this period is unknown. Such knowledge could provide etiologic clues into the cognitive deficits associated with the illness, and could inform early treatment interventions. The purpose of the present study was to evaluate cognitive change in bipolar disorder in the first year after the initial manic episode. METHODS: From an initial pool of 65 newly diagnosed patients with bipolar disorder (within three months of the end of the first manic or mixed episode) and 36 demographically similar healthy participants, 42 patients [mean age 22.9 years, standard deviation (SD) = 4.0] and 23 healthy participants [mean age 22.9 years (SD = 4.9)] completed baseline, six-month, and one-year neuropsychological assessments of multiple domains including processing speed, attention, verbal and nonverbal memory, working memory, and executive function. Patients also received clinical assessments, including mood ratings. RESULTS: Although patients showed consistently poorer cognitive performance than healthy individuals in most cognitive domains, patients showed a linear improvement over time in processing speed (p = 0.008) and executive function (p = 0.004) relative to the comparison group. Among patients, those without a history of alcohol/substance abuse or who were taken off an antipsychotic treatment during the study showed better improvement. CONCLUSIONS: The early course of cognitive functioning in bipolar disorder is likely influenced by multiple factors. Nevertheless, patients with bipolar disorder showed select cognitive improvements in the first year after resolution of their initial manic episode. Several clinical variables were associated with better recovery, including absence of substance abuse and discontinuation of antipsychotic treatment during the study. These and other factors require further investigation to better understand their contributions to longitudinal cognitive functioning in early bipolar disorder.

Sex differences in cognitive functioning in patients with bipolar disorder who recently recovered from a first episode of mania: data from the Systematic Treatment Optimization Program for Early Mania (STOP-EM).

BACKGROUND: Studies investigating bipolar disorder (BD) showed that healthy patterns of sex differences in cognitive functioning are altered within this population, but is it unknown whether these alterations are present in BD patients early in their course of illness. METHODS: Patients with bipolar I disorder (36 males, 38 female), who had recently experienced their first manic or mixed episode were tested along with healthy controls (39 males, 59 females) similar in age, sex and premorbid IQ. Cognitive function was assessed through a comprehensive neuropsychological test battery. RESULTS: Significant group effects were found in a majority of administered tests (p<0.05) with patients performing worse than healthy controls. Significant sex effects (p<0.05) were observed on tasks of spatial working memory and sustained attention, with males performing better than females. No significant group by sex interaction was found in any of the tasks administered. LIMITATIONS: The cognitive battery employed in this study may not have been optimally sensitive in detecting sex differences. CONCLUSIONS: The results suggest that unlike patients with long standing multi-episode BD or schizophrenia, healthy cognitive sex differences are maintained in patients with early BD, following recovery from a first-episode of mania. These findings highlight the progressive nature of the illness and provide justification for an early intervention.