title: Evidence for the Risks and Consequences of Adolescent Cannabis Exposure.
abstract: OBJECTIVE
  This review of the scientific literature examines the potential adult sequelae of exposure to cannabis and related synthetic cannabinoids in adolescence. We examine the four neuropsychiatric outcomes that are likely most vulnerable to alteration by early cannabinoid use, as identified within both the clinical and preclinical research: cognition, emotional functioning, risk for psychosis, and addiction.
  
  
  METHODS
  A literature search was conducted through PubMed, PsychInfo, and Google Scholar with no publication date restrictions. The search terms used were "adolescent" and "adult," and either "cannabis," "marijuana," "delta-9-tetra-hydrocannabinol," or "cannabinoid," which was then crossed with one or more of the following terms: "deficit," "impairment," "alteration," "long-term," "persistent," "development," "maturation," and "pubescent."
  
  
  RESULTS
  The majority of the clinical and preclinical data point to a strong correlation between adolescent cannabinoid exposure and persistent, adverse neuropsychiatric outcomes in adulthood. Although the literature supports the hypothesis that adolescent cannabis use is connected to impaired cognition and mental health in adults, it does not conclusively demonstrate that cannabis consumption alone is sufficient to cause these deficits in humans. The animal literature, however, clearly indicates that adolescent-onset exposure to cannabinoids can catalyze molecular processes that lead to persistent functional deficits in adulthood, deficits that are not found to follow adult-onset exposure and that model some of the adverse outcomes reported in humans among adult populations of early-onset cannabis users.
  
  
  CONCLUSIONS
  Based on the data in the current literature, a strong association is found between early, frequent, and heavy adolescent cannabis exposure and poor cognitive and psychiatric outcomes in adulthood, yet definite conclusions cannot yet be made as to whether cannabis use alone has a negative impact on the human adolescent brain. Future research will require animal models and longitudinal studies to be carefully designed with a focus on integrating assessments of molecular, structural, and behavioral outcomes in order to elucidate the full range of potential adverse and long-term consequences of cannabinoid exposure in adolescence.
authors.affiliation: College of Physicians and Surgeons, Columbia University, and the New York State Psychiatric Institute, New York, NY. Electronic address: ama146@cumc.columbia.edu.
authors.forename: Amir
authors.initials: A
authors.lastname: Levine
authors.affiliation: College of Physicians and Surgeons, Columbia University.
authors.forename: Kelly
authors.initials: K
authors.lastname: Clemenza
authors.affiliation: College of Physicians and Surgeons, Columbia University, and the New York State Psychiatric Institute, New York, NY; New York Presbyterian Hospital-Columbia University Medical Center, New York.
authors.forename: Moira
authors.initials: M
authors.lastname: Rynn
authors.affiliation: College of Physicians and Surgeons, Columbia University, and the New York State Psychiatric Institute, New York, NY; New York Presbyterian Hospital-Columbia University Medical Center, New York.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Lieberman
mesh_terms: D000293:Adolescent; D000328:Adult; D000342:Affective Symptoms / Q000139:chemically induced / Q000209:etiology*; D000818:Animals; D002186:Cannabinoids / Q000009:adverse effects*; D060825:Cognitive Dysfunction / Q000139:chemically induced / Q000209:etiology*; D006801:Humans; D000074609:Marijuana Use / Q000009:adverse effects*; D011618:Psychotic Disorders / Q000209:etiology*; D019966:Substance-Related Disorders / Q000209:etiology*
chemical_list: D002186:Cannabinoids
keywords: adolescent cannabis use; affect; cross-sensitization; executive function; psychosis