Psychostimulant misuse and dementia: an evidence-based review

Psychostimulant misuse is associated with vascular pathology and accelerated brain ageing, both of which increase vulnerability to dementia. This review aimed to examine whether psychostimulant misuse is associated with dementia. Searches were conducted in PubMed, Embase, and PsycINFO bibliographic databases from inception to July 2025. For inclusion, studies had to report incident dementia associated with psychostimulant misuse. Two reviewers independently assessed all search results to identify eligible studies, and all included studies were rated for their methodological quality. From 3128 unique retrieved records, 8 articles met the inclusion criteria and were included. One cohort study and seven case studies reported dementia onset in the context of psychostimulant misuse. Although these studies met the inclusion criteria, the predominance of case studies and the heterogeneity in study designs and outcome measures precluded meta-analysis. Psychostimulants involved were methamphetamine, cocaine, khat and caffeine. The quality of studies was variable. There is emerging evidence to support a link between psychostimulant misuse and dementia, in line with biological and neuroimaging evidence of vascular pathology and accelerated brain ageing associated with psychostimulants. Current evidence is largely derived from a single cohort study and further research is needed. Dementia may have an early onset among those misusing psychostimulants due to increased brain vulnerability. Cognitive and functional impairment in those with psychostimulant misuse should be investigated using standardised dementia screening methods in order to assess for this under-detected condition.