Evidence for pro-cognitive benefits of cannabinoids in people with bipolar disorder

Cannabis use is highly prevalent among people with bipolar disorder, potentially due to a desire to self-medicate against symptoms, such as racing thoughts and poor concentration. Such symptoms are associated with attention and inhibitory control deficits, functions that are regulated in-part by temporal perception. Temporal perception is impaired in BD and is slowed by acute cannabis exposure. The effects of cannabis use (CU) on temporal perception and its associated cognitive functions in people with BD remains unclear. Here, we conducted two studies to 1) test for associations between chronic CU and cognitive function (i.e., attention and inhibitory control) and temporal perception in people with BD and healthy comparison (HC) adults, and 2) investigate the impact of acute Δ9-tetrahydrocannabinol (THC) administration on such functions in a randomized clinical trial in non-CU people with BD and HC adults. Participants completed the Temporal Discrimination Task (TDT) and 5-Choice Continuous Performance Task (5C-CPT). In the chronic CU study, we observed that non-CU BD participants had significantly less precise timing compared to other groups, whereas BD + CU participants had comparable TDT performance to non-CU HC participants. Similarly, BD + CU, but not non-CU BD, participants had comparable 5C-CPT performance to non-CU HC. In the acute THC administration study, we observed faster timing in BD participants administered THC compared to placebo-treated HC participants. These data support that CU in people with BD reflect attempts to self-medicate. Future research will investigate whether cannabinoid-based treatments can remediate cognitive deficits in BD.