Objective: In this study it was aimed to compare male persons with cannabis abuse in terms of schizotypal features with a control group paired in age, sex and education level, and to find a subgroup in the group of cannabis use whose schizotypal points are higher than those having personality disorder as an another factor increasing the tendency of cannabis use.
Method: A total of 251 consequent male patients aged between 18-65 years with cannabis use disorder were admitted to the outpatient clinics of Freedom under supervision of AMATEM of Ankara NumuneHospital for Education and Investigation. Individuals who had an education duration of at least 5 years were included in this study, as self-applied scales are used. The control group consisted of 120 healthy male volunteers matched for age, gender and education-level among physicians and other healthcare professionals from Ankara Numune Hospital and their relatives. The patients and controls were informed about this study, and their written informed consent was obtained, after which their demographic characteristics were recorded. Structured Clinical Interview for DSM-IV-TR for Axis I disorders (SCID-I) and Structured Clinical Interview for DSM-III-R Axis II disorders (SCID-II) were applied, and appropriate candidates were asked to complete the Schizotypal Personality Scale. Substance use was determined by routine urine tests done by the AMATEM laboratory.
Results: The study sample of 371 individuals consisted of 251 patients and 120 controls. The median value of SPD total score was 21 in the cannabis group. The ratio of patients with >21 points was significantly higher after participants with SPD were included in the group without PD (p<0.001). Also, the ratio of individuals who had first used cannabis <18 years in the group with PD (after SPD was excluded) was 44.1%, while it was 24.5% in the group without PD (p=0.004) Especially the use of cannabis, the level of education and income (p<0.001), the decrease of the age of starting to use cannabis (p<0.002), the existence of chronic mental illness in the family, 0.009 the increase of frequency of substance use<0.001, smoking and cannabis in the family <0.001 are seen as important risk factors to predict the schizotypality.
Conclusion: Although there are many studies confirming the relation between cannabis use and schizotypality it is certain that we need to have more large-scale and longitudinal follow-up studies to help us find the direction of this relation. Knowing the direction of this relation will also help us understand the relation between cannabis use and psychosis.