Nicotine, caffeine, alcohol and schizotypy

Schizophrenics are known to be heavy smokers. It has also been reported that in a normal population smoking is associated with higher scores on scales of schizotypy. The present study investigated the use of nicotine as related to scores on a positive symptoms scale of schizotypy. 285 undergraduate students at Rutgers University completed the Rust Inventory of Schizotypal Cognitions (RISC) in addition to a questionnaire regarding smoking habits, caffeine and alcohol use. Results showed a relationship between schizotypy and the use nicotine, and also the use of caffeine and alcohol. Use of the stimulants caffeine and nicotine were associated with higher RISC scores, whereas low stimulant users (nonsmoking, low caffeine users) scored the lowest on the administered scale of schizotypy. The effects of both stimulants were not additive, as demonstrated by a significant interaction between nicotine and caffeine use. The use of alcohol, a CNS depressant, showed the opposite relationship, with increasing alcohol use associated with lower RISC scores. The relationship between schizotypy and increased use of stimulants and decreased use of depressants is discussed.