Case Report: Daily CBD Administration Associated With Remission Of Schizophrenic Symptoms

GERMANY: The adjunctive use of cannabidiol is associated with a remission in schizophrenic symptoms in a patient previously unresponsive to conventional treatment, according to a case report published in the Australian & New Zealand Journal of Psychiatry.

Investigators from the University of Leipzig in Germany assessed the use of twice-daily dosing of 750mg of CBD in conjunction with clozapine in a patient with treatment-resistant schizophrenia. Cannabidiol dosing was associated with remission criteria and improvements remained consistent over eight months.

“Our case report contradicts the assumption that CBD is not likely to be any superior than existing antipsychotics,” authors concluded. “In fact, CBD might be particularly suitable for those patients [who are] resistant to antipsychotics due to its different mode of action.”


For more information, contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, “Remission of severe, treatment-resistant schizophrenia following adjunctive cannabidiol,” appears in the Australian & New Zealand Journal of Psychiatry.

Study: Long-Term Cannabis Use Not Associated With Changes In Brain Morphology

AUSTRALIA: The use of cannabis, even long-term, is not associated with changes in the cortical surface of the brain, according to data published in the journal European Neuropsychopharmacology.

A team of investigators from Australia and the Netherlands assessed the relationship between cannabis use and brain morphology in a cohort of 261 subjects (141 cannabis users and 120 controls). Researchers reported “no significant effects on cortical surface morphology” that could be attributable to subjects’ cannabis use, dependence, or age of initiation.

Authors concluded, “Our lack of finding in a well-powered study suggests that cortical surface morphology may be less associated with cannabis use than previously assumed.”

The findings are consistent with other recent brain imaging studies – such as those herehere, and here – and are largely inconsistent with those of a well-publicized 2014 study purporting that even causal cannabis exposure was linked to changes in the brain in young people.


For more information, contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, “Cortical surface morphology in long-term cannabis users: A multi-site MRI study,” appears in European Neuropsychopharmacology. Further information is available from the NORML fact-sheet, “Marijuana Exposure and Cognitive Performance.”

Cannabis Use Associated With Improved Outcomes In Bipolar Patients

MASSACHUSETTS: Cannabis use is associated with an alleviation of clinical symptoms in patients with bipolar disorder, and does not negatively impact cognitive performance, according to clinical trial data published in the journal PLoS One.

Investigators with Harvard Medical School, Tufts University, and McLean Hospital in Massachusetts assessed the impact of marijuana use on mood symptomology and cognitive function in patients with bipolar disorder.

Authors reported that marijuana use was associated with lower scores of anger, tension, and depression, as well as higher levels of vigor in BPD patients. Subjects who used marijuana also showed no significant differences in cognitive performance compared to BPD subjects who abstained from the plant. The study is the first clinical trial to assess the impact of cannabis on both mood and neuropsychological performance in BPD patients.

Researchers concluded, “The current study highlights preliminary evidence that patients with BPD who regularly smoked marijuana reported at least short-term clinical symptom alleviation following marijuana use, indicating potential mood-stabilizing properties of marijuana in at least a subset of patients with BPD.”


For more information, contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, “A pilot investigation of the impact of bipolar disorder and marijuana use on cognitive function and mood,” appears in PLoS One.

Study: Cannabis Use Not An Independent Risk Factor For Increased Likelihood Of Psychotic Symptoms

PENNSYLVANIA: There exists “minimal evidence” in support of an association between cannabis use by itself and the onset of psychotic symptoms in young people, according to data published online ahead of print in the Journal of Adolescent Health.

Investigators from the University of Pennsylvania, Department of Psychiatry assessed the relationship between drug use and the onset of psychotic symptoms in a cohort of 4,171 young people ages 14 to 21. Authors reported that “neither frequent nor early cannabis use predicted increased odds of psychosis spectrum classification” after researchers adjusted for potential confounders (e.g., concurrent use of other substances, comorbid psychopathology, and trauma exposure).

They concluded, “Overall, we found minimal evidence for associations between cannabis use by itself and psychosis spectrum symptoms.”

The findings are similar to those of a 2015 longitudinal study reporting that early-onset cannabis use is not positively associated with a greater risk of psychosis or other mental health disorders in mid-life.

A 2016 literature review published in the journal Current Psychiatry Reports concluded that cannabis use likely does not cause the psychosis, but rather, that subjects susceptible to the disorder may be more likely to engage in habitual use of the substance.