Childhood trauma and substance use underlying psychosis: a systematic review.

: Schizophrenia spectrum disorders (SSD) are mental diseases caused by a combination of genetic susceptibility and a number of environmental factors. Among these factors, the role of traumatic events suffered in childhood, as well as that of substance use, have been of particular research interest. : To conduct a systematic review to clarify whether there is an interaction between childhood trauma and substance use related to the diagnosis or symptoms of SSD. It was also the objective of this review to collate the associations that may exist between the three variables of the study (trauma, substance use and psychosis). : We conducted a systematic search resulting in 240 articles. We considered all of the original articles that explored childhood trauma and substance use in patients suffering from SSD. : Twenty-three articles were selected for this review. Several of the reviewed papers found associations between childhood trauma and substance use with SSD, as well as interactions between trauma and drug use on SSD. : The results suggest that childhood trauma and substance use may be present at the basis of psychosis. This double hit on the pathogenesis could have clinical implications, since each of these impacts could be considered a window of opportunity for the primary prevention of SSD.