Associated with worse working memory, executive function, information processing speed
TUESDAY, March 29 (HealthDay News) -- Cannabis use among multiple sclerosis (MS) patients is associated with negative impacts on cognitive function, according to a study published in the March 29 issue of Neurology.
Kimia Honarmand, of the University of Toronto, and colleagues administered the Minimal Assessment of Cognitive Function in MS battery of neuropsychological tests, the Hospital Anxiety and Depression Scale (HADS), and the Structured Clinical Interview for the DSM-IV Axis I Disorders (SCID-I) to 25 MS patients who used cannabis and 25 MS patients who did not use cannabis, aged 18 to 65 years.
Compared to cannabis nonusers, the investigators found that cannabis users performed significantly more poorly on measures of information processing speed, working memory, executive function, and visuospatial perception. Cannabis users were twice as likely as nonusers to be considered globally cognitively impaired. However, the researchers did not find between-group differences on the HADS measures of anxiety and depression or lifetime SCID-I psychiatric diagnoses.
"This cross-sectional study provides empirical evidence that prolonged use of inhaled or ingested street cannabis in patients with MS is associated with poorer performance on cognitive domains commonly affected in this population. Whatever subjective benefits patients may derive from using street cannabis (e.g., pain and spasticity relief) should be weighed against the associated cognitive side effects," the authors write.
Several study authors disclosed financial ties to pharmaceutical and/or medical device companies.
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