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 .
Cannabidiol (CBD) as an Adjunctive Therapy in Schizophrenia: A Multicenter Randomized Controlled Trial.
OBJECTIVE Research in both animals and humans indicates that cannabidiol ( CBD ) has antipsychotic properties . The authors assessed the safety and effectiveness of CBD in patients with schizophrenia . METHOD In an exploratory double-blind parallel-group trial , patients with schizophrenia were r and omized in a 1:1 ratio to receive CBD ( 1000 mg/day ; N=43 ) or placebo ( N=45 ) alongside their existing antipsychotic medication . Participants were assessed before and after treatment using the Positive and Negative Syndrome Scale ( PANSS ) , the Brief Assessment of Cognition in Schizophrenia ( BACS ) , the Global Assessment of Functioning scale ( GAF ) , and the improvement and severity scales of the Clinical Global Impressions Scale ( CGI-I and CGI-S ) . RESULTS After 6 weeks of treatment , compared with the placebo group , the CBD group had lower levels of positive psychotic symptoms ( PANSS : treatment difference=-1.4 , 95 % CI=-2.5 , -0.2 ) and were more likely to have been rated as improved ( CGI-I : treatment difference=-0.5 , 95 % CI=-0.8 , -0.1 ) and as not severely unwell ( CGI-S : treatment difference=-0.3 , 95 % CI=-0.5 , 0.0 ) by the treating clinician . Patients who received CBD also showed greater improvements that fell short of statistical significance in cognitive performance ( BACS : treatment difference=1.31 , 95 % CI=-0.10 , 2.72 ) and in overall functioning ( GAF : treatment difference=3.0 , 95 % CI=-0.4 , 6.4 ) . CBD was well tolerated , and rates of adverse events were similar between the CBD and placebo groups . CONCLUSIONS These findings suggest that CBD has beneficial effects  in patients with schizophrenia . As CBD 's effects do not appear to depend on dopamine receptor antagonism , this agent may represent a new class of treatment for the disorder
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 .