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: Medical Cannabis Associated With Improved Cognitive Performance, Reduced Opioid Use

MASSACHUSETTS: Medical cannabis administration is associated with improved cognitive performance and lower levels of prescription drug use, according to longitudinal data published online in the journal Frontiers in Pharmacology.

Investigators from Harvard Medical School, Tufts University, and McLean Hospital evaluated the use of medicinal cannabis on patients’ cognitive performance over a three-month period. Participants in the study were either naïve to cannabis or had abstained from the substance for at least ten years. Baseline evaluations of patients’ cognitive performance were taken prior to their cannabis use and then again following treatment.

Researchers reported “no significant decrements in performance” following medical marijuana treatment. Rather, they determined, “[P]atients experienced some improvement on measures of executive functioning, including the Stroop Color Word Test and Trail Making Test, mostly reflected as increased speed in completing tasks without a loss of accuracy.”

Participants in the study were less likely to experience feelings of depression during treatment, and many significantly reduced their use of prescription drugs. “[D]ata revealed a notable decrease in weekly use across all medication classes, including reductions in use of opiates (-42.88 percent), antidepressants (-17.64 percent), mood stabilizers (-33.33 percent), and benzodiazepines (-38.89 percent),” authors reported – a finding that is consistent with prior studies.

Patients in the study will continue to be assessed over the course of one-year of treatment to assess whether these preliminary trends persist long-term.

For more information, please contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, “Splendor in the grass? A pilot study assessing the impact of marijuana on executive function,” appears in Frontiers of Pharmacology.