Cannabis consumption is related to better premorbid adjustment and cognitive performance on first episode schizophrenia patients

Abstract

Studies on the influence of cannabis consumption over cognitive and clinical variables on schizophrenia have yielded contradictory findings. Whereas some studies have found cognitive impairments in those schizophrenic patients that used the substance others did not find any difference and some others have reported a better performance of patients that consume the substance. Some authors state that schizophrenic patients who consume cannabis constitute a differentiated subgroup of patients that along with more positive symptoms and less negative symptoms would have better cognitive and social skills necessary to engage on drug consumption related behaviours. In the current work 104 first episode schizophrenia patients were divided into two groups of cannabis consumption (consumers vs. non consumers). Their premorbid adjustment was assessed and they were studied along their fist year of illness on cognitive and clinical variables. Results revealed that consumers outperformed non consumers on tasks related to attention and executive functions. They also presented more positive symptoms at illness onset and had a better premorbid adjustment. These results give support to the hypothesis of cannabis consumer schizophrenic patients as a different subgroup of subjects.