Cannabis and Thought Disorder in Schizophrenia

Hôpital le Vinatier63 enrolled

Overview

Recent studies have suggested a strong relationship between cannabis use and the level of thought disorder in subjects with schizophrenia. Moreover, the level of thought disorder has been associated with an increased functional connectivity between the temporal lobe and the Putamen. However, the brain mechanisms underlying these two relationships are still poorly known. Better understanding these mechanisms is important to improve patients' care, in particular among treatment-resistant patients. The objective of the CANDI study consists of assessing whether the level of cannabis use in patients with schizophrenia modulates the level of thought disorder via a modulation of the functional connectivity between the temporal lobe and the Putamen. Analyses will be controlled for the composition of cannabis, in particular the tetrahydrocannabinol / cannabidiol ratio.

25 subjects with schizophrenia and current cannabis use will be recruited in the experimental group. The control group will consist of 25 subjects with schizophrenia but with no cannabis use.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Schizophrenia

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Aged between 18 and 65 * Meeting the DSM-5 criteria for schizophrenia * "Cannabis user" group: - Smoking at least two days per week during the previous months * Displaying positive urine screen for cannabis * "Non-cannabis user" group: - No episode of cannabis smoking during the previous month * Negative urine screen for cannabis + no lifetime criteria for cannabis use disorder (assessment by an addiction specialist). Exclusion Criteria: * Current criteria for axis-1 psychiatric disorder other than schizophrenia * Current criteria for any other substance use disorder except for nicotine use disorder * Any contraindication for MRI * Tutorship or curatorship * Pregnant or lactating woman

Outcomes

Primary Outcomes

Level of thought disorder

The level of thought disorder will be investigated using the specific items of the Positive And Negative Syndrome Scale (PANSS; Kay et al., 1987) Minimum score 1 Maximum score 7

Time frame: one year

Secondary Outcomes

cannabis use

cannabis use (yes vs. no; i.e., the group factor)

Time frame: one year

Delta-9 tetrahydrocannabinol (THC) concentration

Concentrations of Delta-9 tetrahydrocannabinol in the cannabis usually smoked

Time frame: one year

Cannabidiol (CBD) concentration

Concentration of cannabidiol in the cannabis usually smoked

Time frame: one year

Cannabis and Thought Disorder in Schizophrenia

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes