Long-term cannabis use has been associated with the appearance of psychotic symptoms and schizophrenia-like cognitive impairments; however these studies may be confounded by concomitant use of tobacco by cannabis users. We aimed to determine if previously observed cannabis-associated deficits in sensory gating would be seen in cannabis users with no history of tobacco use, as evidenced by changes in the P50, N100, and P200 event-related potentials. A secondary objective of this study was to examine the effects of acute nicotine administration on cannabis users with no tobacco use history.
Three components (P50, N100, P200) of the mid-latency auditory-evoked response (MLAER) were elicited by a paired-stimulus paradigm in 43 healthy, non-tobacco smoking male volunteers between the ages of 18-30. Cannabis users (CU, n = 20) were administered nicotine (6 mg) and placebo gum within a randomized, double-blind design. Non-cannabis users (NU, n = 23) did not receive nicotine.
Between-group sensory gating effects were only observed for the N100, with CUs exhibiting a smaller N100 to S of the paired stimulus paradigm, in addition to reduced dN100 (indicating poorer gating). Results revealed no significant sensory gating differences with acute administration of nicotine compared to placebo cannabis conditions.
These findings suggest a relationship between gating impairment and cannabis use; however, acute nicotine administration nicotine does not appear to impact sensory gating function.