Bertha Madras, professor of psychobiology at Harvard Medical School, has printed a critique listing 20 flaws to a recent study finding no differences in physical or mental health problems between users and non-users of marijuana.
The long-term marijuana use study led by Jordan Bechtold, of the University of Pittsburgh School of Medicine, was published earlier this month in the Journal of Psychology of Addictive Behaviors. Bechtold et al., followed 408 participants for over 20 years and found no association between marijuana use at a young age and an increased risk of psychosis, depression, and anxiety in adulthood.
See MIA’s coverage of Bechtold’s study here →
“A critical evaluation of the validity of the findings and sweeping conclusions is essential, lest they are interpreted inappropriately. A perusal of the study and the authors’ stated caveats in the manuscript reveal significant weaknesses, with the use of an unrepresentative, possible archaic population, inadequate sample size, inadequate methodologies to assess mental health and physical problems, (self-reports, evaluation of psychiatric status without considering the “spectrum” nature of psychiatric conditions, and absence of addiction evaluation). The findings conflict with other well designed longitudinal studies that assess long-term consequences of marijuana use with early age of initiation of marijuana.”
See Madras’ full response here →