Obsessive-compulsive symptoms in dementia: Systematic review with meta-analysis.

Dementia is a highly prevalent syndrome with various causes, characterized by cognitive deficit in one or more domains, with important impairment of functioning, which frequently presents with neuropsychiatric symptoms that may include obsessive-compulsive symptoms.

Objectives: The main goal of this meta-analysis was to describe and determine the prevalence of obsessive-compulsive symptoms in dementia.

Materials and methods: To accomplish that, MEDLINE, CENTRAL and Psycnet databases were searched from inception to March 2023. The Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data was applied. The principal summary measures were the mean of prevalence of obsessive-compulsive symptoms in patients with dementia and the number of each type of obsession or compulsion.

Results: Of the 643 articles screened, 92 were accepted for full-text assessment. Of these, 30 with information on prevalence of obsessive-compulsive symptoms in dementia or any description of those were included, yielding a total of 37 cohorts (5 studies with two cohorts and 1 study with three cohorts). According to our results, obsessive-compulsive symptoms have considerable prevalence in dementia (35.3%, 23.1-47.6%), namely in frontotemporal dementia (48.4%, 29.8-67.0%); obsessive-compulsive symptoms were less frequent in other dementia diagnosis (17.6%, 9.1-26.2%). The more frequent obsessive contents are symmetry (28.6%) and somatic (20.0%); and the more frequent compulsions are checking (27.4%); hoarding is also a relevant symptom (27.8%).

Discussion: There was considerable heterogeneity in the prevalence of obsessive-compulsive symptoms in frontotemporal dementia, that is, in part related with diagnostic criteria for dementia, as well as obsessive-compulsive symptom assessment. A careful distinction between compulsions and compulsive-like symptoms is fundamental. Hypervigilance for somatic symptoms and concerns about disease and mortality, as well as deficits in cognitive domains like attention and memory may explain why somatic obsessions and checking compulsions are more prevalent.

Conclusions: The present results indicate that obsessive-compulsive symptoms may be prevalent in the clinical course of many patients with dementia, especially frontotemporal dementia. Better instruments are needed to describe obsessive-compulsive phenomena in a reliable and comparable way, particularly in a population such as dementia patients, whose subjectivity is difficult to access.