A recent study by Saha et al. (2011) explored the association between delusional-like experiences (DLE) and three commonly used substances – tobacco, alcohol, and cannabis. With respect to tobacco use, compared to nonusers, DLE were more common in those who smoked daily, began smoking before the age of 16, and smoked heavily (>22 cigarettes per day). DLE were also more common among both cannabis and alcohol users, and were most prominent among early onset users. The authors conclude that the influences of these three substances on psychosis-related outcomes warrants closer scrutiny in longitudinal prospective studies.
Saha S, Scott JG, Varghese D, Degenhardt L, Slade T, and McGrath JJ. The association between delusional-like experiences, and tobacco, alcohol or cannabis use: a nationwide population based survey. BMC Psychiatry 2011,11:202 (abstract)