Regular Research Article
Cognitive Trajectories in Comorbid Dementia With Schizophrenia or Bipolar Disorder: The South London and Maudsley NHS Foundation Trust Biomedical Research Centre (SLaM BRC) Case Register

https://doi.org/10.1016/j.jagp.2020.10.018Get rights and content
Under a Creative Commons license
open access

Highlights

  • We compared the cognitive trajectories in individuals with dementia with and without comorbid severe mental illness using data from one of the largest mental health care providers in Europe.

  • Our results showed that individuals with comorbid SMI were more likely to have a faster decline in their MMSE scores compared with those that had dementia without this comorbidity. However, this association was attenuated when considering socio-demographics, smoking and cardiovascular risk factors and medication.

  • Our findings highlight the potential risk for an accelerated cognitive decline in this group of individuals, specially for those with bipolar disorders, and the need to further investigate the role of potential shared mechanisms.

Abstract

Objectives

We aimed to compare trajectories of cognitive performance in individuals diagnosed with dementia with and without severe mental illness (SMI).

Design

Retrospective cohort study.

Setting

We used data from a large longitudinal mental healthcare case register, the Clinical Record Interactive Search (CRIS), at the South London and Maudsley NHS Foundation Trust (SLaM) which provides mental health services to four south London boroughs.

Participants

Our sample (N = 4718) consisted of any individual who had a primary or secondary diagnosis of dementia from 2007 to 2018, was 50 years old or over at first diagnosis of dementia and had at least 3 recorded Mini-Mental State Examination (MMSE) scores.

Measurements

Cognitive performance was measured using MMSE. Linear mixed models were fitted to explore whether MMSE trajectories differed between individuals with or without prior/current SMI diagnoses. Models were adjusted by socio-demographics, cardiovascular risk, smoking, and medication.

Results and conclusions

Our results showed differences in the rate of change, where individuals with comorbid SMI had a faster decline when compared with those that have dementia without comorbid SMI. However, this association was partially attenuated when adjusted by socio-demographics, smoking and cardiovascular risk factors; and more substantially attenuated when medication was included in models. Additional analyses showed that this accelerated decline might be more evident in individuals with bipolar disorders. Future research to detangle the potential biological underlying mechanisms of these associations is needed.

Key Words

Dementia
severe mental illness
cognitive decline
electronic health records

Cited by (0)

#

Joint first authors.