Evaluation of the effect of schizotypy on cannabis use predictors

Abstract

OBJECTIVES: 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. METHODS: A total of 251 consequent male patients aged between 18 and 65 years with cannabis use disorder were admitted to the outpatient clinics of Freedom under supervision of AMATEM of Ankara Numune Hospital 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 schizotypal personality disorder (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 personality disorder (PD) (p < .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 = .004). Especially, the use of cannabis, the level of education and income (p < .001), the decrease of the age of starting to use cannabis (p < .002), the existence of chronic mental illness in the family (p = .009), the increase of frequency of substance use (p < .001), and smoking and cannabis in the family (p < .001) are seen as important risk factors to predict the schizotypality. CONCLUSIONS: 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.

Characterizing psychosis-relevant phenomena and cognitive function in a unique population with isolated, chronic and very heavy cannabis exposure

“…Consistent with this, we noted higher schizotypal scores in cases compared with controls, with elevated scores in the ‘odd beliefs and magical thinking,’ ‘unusual perceptual experience,’ and ‘odd and eccentric behavior’ subdomains. Several studies have observed a similar association between cannabis use and higher schizotypy scores, but many of these studies did not control for other drug/alcohol use (Skosnik et al ., 2008; Eren et al ., 2017). There is also some support for a causal influence of early cannabis exposure on later emergence of schizotypal symptoms during adulthood (Anglin et al ., 2012).…”