Cognitive impairment in late life bipolar disorder: Risk factors and clinical outcomes

Background: Late Life Bipolar Disorder (LLBD) is associated with a high prevalence of cognitive impairments, but few studies have examined their risk factors and clinical correlates Methods: Participants with bipolar disorder older than 60 (n = 86) were recruited from psychiatric outpatient and inpatients units. Patients were assessed with various instruments, including the Clinical Dementia Rating scale, the Montreal Cognitive Assessment and the Cumulative Illness Rating Scale. The distribution of disorder-specific and general risk factors was compared between patients with LLBD plus cognitive impairments (mild cognitive impairment or dementia) and those with LLBD but no cognitive impairment. Analyses were first conducted at the bivariate level, then using multiple regression. The association with disability, aggressive behavior and suicidal ideation was also explored. Results: Cognitive impairments in LLBD were associated with a diagnosis of type 1 bipolar disorder (OR = 6.40, 95%CI: 1.84 – 22.31, p = 0.004), fewer years of education (OR = 0.79, 95%CI: 0.69 – 0.91, p = 0.001) and higher severity of physical diseases (OR 26.54, 95%CI: 2.07 – 340.37, p = 0.01). Moreover, cognitive impairments were associated with an increased likelihood of disability and recent aggressive behavior, but not suicidal ideation. Limitations: retrospective design, conflation of MCI and dementia, not all subjects were in euthymia Conclusions: In LLBD, the presence of cognitive impairments was associated with a diagnosis of type I bipolar disorder, lower education and more severe physical comorbidities. In turn, MCI or dementia were associated with increased disability and aggressive behavior. These findings may aid the identification of patients at risk for cognitive deterioration in everyday clinical practice.