Adina Fischer, M.D., Ph.D.
Fellow in Depression
Manpreet K. Singh, M.D., M.S.
Alan Schatzberg, M.D.
Investigating the neurobiological effects of cannabis in adolescent depression
Adolescence is a vulnerable period of brain development and peak risk period for onset of depression. Depressed adolescents who use cannabis have a worsened course with more severe symptomatology and greater treatment challenges relative to non-users. Over the past decade, cannabis potency has markedly increased, and more frequent cannabis use has been linked to onset and severity of depressive symptoms in adolescence. This raises a significant public health concern given the rapidly changing landscape surrounding cannabis legalization, and the decline in perceived risks of regular cannabis use among adolescents. Improving our understanding of the effects of cannabis on adolescent neurobiology and psychiatric symptom manifestation is of critical importance. Preclinical studies have found that cannabis exposure disrupts brain and neuroendocrine reward and stress circuitry, whose dysfunction is implicated in adolescent depression. This project aims to investigate the neurobiological effects of adolescent cannabis exposure on reward and stress systems, as well as the mechanisms that link these effects to depressive symptoms in adolescents with and without major depressive disorder. We will collect hair samples to quantify cannabis exposure and cortisol levels, as well as functional neuroimaging (fMRI) to examine brain circuitry. We hypothesize that adolescent exposure to higher potency cannabis will lead to (1) more severe depressive symptoms, as well as greater (2) brain reward circuit and (3) neuroendocrine dysfunction. We hope that this work will improve prevention and intervention strategies for depressed youth whose symptom and treatment course are negatively impacted by substance use.