Several neurological and mental health disorders have notable sex differences in their prevalence or severity, which can be further amplified when co-morbidity is considered.  We are currently studying the effect of circulation sex hormones on the function of the lateral habenula - rostromedial tegmental nucleus - midbrain dopamine pathway, which is implicated in many of these disorders. This research will help us to understand whether this brain circuit underlies sex differences in several recalcitrant mental health disorders and may lead to new forms of treatment.