In Reply We appreciate the additional points that Solowij et al contribute to this important discussion.1 The uncertainty regarding the relationship between exposure parameters and neural substrates on one hand and persistence or decay of cognitive impairment and the associated neurobiological changes on the other is indeed a critical and challenging problem that might be optimally addressed by prospective studies with sufficient sample sizes to account for the diverse genetic, social, and developmental trajectories of individuals and that uses standardized measures of cannabis and other drug exposures.
Volkow ND. Effects of Cannabis Use on Human Behavior—Reply. JAMA Psychiatry. 2016;73(9):996. doi:10.1001/jamapsychiatry.2016.1332