Objective A number of studies showed cognitive impairment in bipolar patients but few researches have studied the impact of mood episodes or duration of illness on neuropsychological functioning.
Methods Cognitive functioning was examined in 110 bipolar 1 outpatients with different mood state (mania, major depression, mixed episode and euthymia). The neuropsychological battery included The Visual Search Test, Trail Making Test, Corsi Test, Frontal Assessment Battery (FAB), Cognitive Estimation Task (CET) and Tower of London and it assessed attention, memory and executive/planning functions. Failures in the different cognitive tests were compared between groups using χ2 tests with Bonferroni's corrections. Finally a binary logistic regression was performed in order to find an eventual association between age and duration of illness and CET bizarreness.
Results All the symptomatic patients (manic, depressed, mixed) failed more frequently The Visual Search Test in comparison with euthymics (χ2 = 9.882, df = 3, p = 0.017, phi = 0.30; rate of failures: manic patients 32.2%, depressed patients 30.6%, euthymics 0%, mixed patients 18.2%). CET was performed worse by manic and euthymic patients (χ2 = 10.086, df = 3, p = 0.015, phi = 0.31; rate of failures: manic patients 46.4%, depressed patients 22.9%, euthymics 52.1%, mixed patients 18.2%). Finally, a longer duration of illness was found to be predictive of more bizarreness at CET (OR = 1.06, p = 0.01).
Conclusions Bipolar patients present impairment in different cognitive domains even in euthymic phases. Frontal dysfunction might be associated with a long duration of illness as shown by number of bizarreness at CET in chronic bipolar patients.
ASJC Scopus subject areas
- Psychiatry and Mental health
- Clinical Psychology