3. Sex differences in drug use and drug addiction from a neuroscience perspective

While on average, one third of individuals with a substance use disorder (SUD) is female, sex differences in the neural working mechanisms of SUD are poorly investigated. Clinical research suggest that females, in general, progress more rapidly to SUD, have more severe co-morbid disorders and experience higher rates of stress-related substance use and relapse compared to males. It has been hypothesized that the development of SUD in males is more strongly driven by neural pathways involved in positive reinforcement (reward-craving) while in females it is suggested to be more strongly driven by neural pathways involved negative reinforcement (stress-relief craving). Here we present results from different neuroimaging studies aimed at identifying sex differences in the neural pathways involved in negative reinforcement (using a negative emotional cue reactivity MRI task) and positive reinforcement (using an alcohol, cannabis or cocaine cue reactivity MRI task).