August 2012
Glen Oaks, NY: Bipolar patients with a history of cannabis use demonstrate superior neurocogitive performance compared to patients with no history of use, according to clinical data published online in the journal Psychiatry Research.
Investigators at The Zucker Hillside Hospital in Long Island, NY, along with researchers at the Mount Sinai School of Medicine and the Albert Einstein College of Medicine in New York City compared the performance of 50 bipolar subjects with a history of cannabis use versus 150 bipolar patients with no history of use on a battery of standardized cognitive measures. Patient groups did not differ regarding age, racial background, or highest education level achieved. Bipolar patients with a history of cannabis use had similar age at onset as did patients who did not consume cannabis.
Researchers found that subjects with a history of cannabis use exhibited better neurocognitive performance than that of non-users, but they did not differ significantly on estimates of premorbid IQ.
Authors reported, “Results from our analysis suggest that subjects with bipolar disorder and history of (cannabis use) demonstrate significantly better neurocognitive performance, particularly on measures of attention, processing speed, and working memory. These findings are consistent with a previous study that demonstrated that bipolar subjects with history of cannabis use had superior verbal fluency performance as compared to bipolar patients without a history of cannabis use. Similar results have also been found in schizophrenia in several studies.”
They concluded, “These data could be interpreted to suggest that cannabis use may have a beneficial effect on cognitive functioning in patients with severe psychiatric disorders. However, it is also possible that these findings may be due to the requirement for a certain level of cognitive function and related social skills in the acquisition of illicit drugs.”
For more information, please contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, “Cognitive and clinical outcomes associated with cannabis use in patients with bipolar I disorder,” will appear in Psychiatry Research.