Can we draw an identikit of cannabis smokers who may be at higher risk of developing a psychosis?

The purpose of this review is to identify somatic and environmental factors, which make some people more at risk of developing psychosis in connection with the use of cannabis.Were selected in PubMed studies of the last 20 years that have assessed the main factors of vulnerability to psychosis (premorbid personality, family history of psychosis, gender, genetic predisposition, adolescence, childhood trauma, use of other substances, social context, use of internet) and the additive effect of cannabis use.From the literature the existence of a subgroup of subjects prone to the development of psychotic disorders emerges with good evidence, which is characterized by features such as: male gender, premorbid schizotypal personality traits, early use of cannabis in adolescence, family history of psychiatric illness, personal history of abuse and childhood trauma, tendency to social anxiety. The evidences about a genetic predisposition are scarce, and there are few studies in this regard; there is a growing interest in internet addiction and its relationship with drug addiction.Despite the paucity of studies on the vulnerability to psychosis and the additive effect of cannabis use, the topic is of considerable interest, especially for the purpose of sound clinical practice aimed at preventon of psychiatric disorders, and for the correct address of social policies on the use of substances.