Cognitive performance in older‐age bipolar disorder: Investigating psychiatric characteristics, cardiovascular burden and psychotropic medication

Abstract

Objective This study aimed to explore a large range of candidate determinants of cognitive performance in older‐age bipolar disorder (OABD). Methods A cross‐sectional study was performed in 172 BD patients aged ≥50 years. Demographics, psychiatric characteristics and psychotropic medication use were collected using self‐report questionnaires and structured interviews. The presence of cardiovascular risk factors was determined by combining information from structured interviews, physical examination and laboratory assessments. Cognitive performance was investigated by an extensive neuropsychological assessment of 13 tests, covering the domains of attention, learning/ memory, verbal fluency and executive functioning. The average of 13 neuropsychological test Z‐scores resulted in a composite cognitive score. A linear multiple regression model was created using forward selection with the composite cognitive score as outcome variable. Domain cognitive scores were used as secondary outcome variables. Results The final multivariable model (N = 125), which controlled for age and education level, included number of depressive episodes, number of (hypo)manic episodes, late onset, five or more psychiatric admissions, lifetime smoking, metabolic syndrome and current use of benzodiazepines. Together, these determinants explained 43.0% of the variance in composite cognitive score. Late onset and number of depressive episodes were significantly related to better cognitive performance whereas five or more psychiatric admissions and benzodiazepine use were significantly related to worse cognitive performance. Conclusion Psychiatric characteristics, cardiovascular risk and benzodiazepine use are related to cognitive performance in OABD. Cognitive variability in OABD thus seems multifactorial. Strategies aimed at improving cognition in BD should include cardiovascular risk management and minimizing benzodiazepine use.

Cognition in older adults with bipolar disorder: An ISBD task force systematic review and meta‐analysis based on a comprehensive neuropsychological assessment

“…In one study focused in OABD, benzodiazepines were linked to worse cognitive performance but no such effect was observed with other medications (anticonvulsants, antipsychotics, or antidepressant). 98 On the contrary, there is evidence that lithium has potential long-term neuroprotective effects, increasing neuroplasticity with changes observed in white matter, [99][100][101][102] reducing the oxidative stress as well as increasing protective proteins such as neurotrophic factor, among others. 103 In fact, lithium has been identified as a potential protective factor for the development of dementia.…”

“…In addition to that, medication may also be considered as a confounding factor since the cumulative effects of psychotropic medications over the life course of OABD are likely to be of particular relevance to cognition and cognitive decline with age. In one study focused in OABD, benzodiazepines were linked to worse cognitive performance but no such effect was observed with other medications (anticonvulsants, antipsychotics, or antidepressant) 98 . On the contrary, there is evidence that lithium has potential long‐term neuroprotective effects, increasing neuroplasticity with changes observed in white matter, 99–102 reducing the oxidative stress as well as increasing protective proteins such as neurotrophic factor, among others 103 .…”

Illness progression in older‐age bipolar disorder: Exploring the applicability, dispersion, concordance, and associated clinical markers of two staging models for bipolar disorder in an older population

“…Benzodiazepines were not considered indicative of treatment resistance. Two variables for cognitive performance were used: MMSE and a ‘composite cognitive score’ based on a full neuropsychological assessment, calculating the mean of 13 neuropsychological test Z‐scores 21 . The composite cognitive score was corrected for age and education level.…”

“…Detailed information on data collection, measurement, operationalization, and definitions of all investigated variables are available in previous publications from our group. 13,21 Application of staging models A and B to the OABD study sample.…”

Functioning in older adults with bipolar disorder: A report on recommendations by the International Society of bipolar disorder (ISBD) older adults with bipolar disorder (OABD) task force

“…27 Indeed, it is also described that more severe depression, somatic comorbidities, and impaired cognition were all associated with lower functioning in OABD. 28,29 Moreover, findings from the Global Aging & Geriatric Experiments in Bipolar Disorder (GAGE-BD) study 30 suggest that greater severity of symptoms in BD is associated with worse functioning in OABD. 31…”