The results show that , in particular , frequent cannabis use , especially daily use , and the consumption of high-potency cannabis are associated with a higher risk of developing psychosis .
Moreover , several genotypes moderate the impact of cannabis use on psychosis risk , particularly those involved in the dopamine function , such as AKT1 .
Finally , cannabis use is associated with an earlier psychosis onset and increased risk of transition in individuals at a clinical high risk of psychosis .
These findings indicate that changing cannabis use behavior could be a harm reduction strategy employed to lower the risk of developing psychosis .
Increasing evidence indicates a relationship between  cannabis use and psychosis risk .
Specific factors , such as determinants of cannabis use or the genetic profile of cannabis users , appear to moderate this association .
The present systematic review presents a detailed and up-to- date literature overview on factors that influence the relationship between cannabis use and psychosis risk .
Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study
Papers pp 1195 , 1199 The strongest evidence that cannabis use may be a risk factor for later psychosis  comes from a Swedish cohort study which found that heavy cannabis use at age 18 increased the risk of later schizophrenia sixfold . 1 2 This study could not establish whether adolescent cannabis use was a consequence of pre-existing psychotic symptoms rather than a cause . We present the first prospect i ve longitudinal study of adolescent cannabis use as a risk factor for  adult schizophreniform disorder  , taking into account childhood psychotic symptoms3 antedating cannabis use . View this table : Association between  cannabis use in adolescence and schizophrenia and depressive symptoms and disorders at age 26 ( n=759 ) , controlling for childhood psychotic symptoms and use of other drugs in adolescence The Dunedin multidisciplinary health and development study ( a study of a general population birth cohort of 1037 individuals born in Dunedin , New Zeal and , in 1972 - 3)4 has a 96 % follow up rate at age 26 . It obtained information on psychotic symptoms at age 11 and drug use at ages 15 and 18 from self reports and assessed
The results show that , in particular , frequent cannabis use , especially daily use , and the consumption of high-potency cannabis are associated with a higher risk of developing psychosis .
Moreover , several genotypes moderate the impact of cannabis use on psychosis risk , particularly those involved in the dopamine function , such as AKT1 .
Finally , cannabis use is associated with an earlier psychosis onset and increased risk of transition in individuals at a clinical high risk of psychosis .
These findings indicate that changing cannabis use behavior could be a harm reduction strategy employed to lower the risk of developing psychosis .
Increasing evidence indicates a relationship between  cannabis use and psychosis risk .
Specific factors , such as determinants of cannabis use or the genetic profile of cannabis users , appear to moderate this association .
The present systematic review presents a detailed and up-to- date literature overview on factors that influence the relationship between cannabis use and psychosis risk .