Schizophrenia
Conditions
Keywords
Schizophrenia ; Cannabis
Brief summary
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.
Detailed description
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.
Interventions
OTHERCannabis and thought disorder in schizophrenia:clinical and neuroimaging relationships
To investigate whether the level of cannabis use in schizophrenic patients influences the symptoms of psychic disorganization via modulation of cerebral connectivity between the temporal lobe and the putamen.
Sponsors
Hôpital le Vinatier
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Level of thought disorder | one year | 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 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| cannabis use | one year | cannabis use (yes vs. no; i.e., the group factor) |
| Delta-9 tetrahydrocannabinol (THC) concentration | one year | Concentrations of Delta-9 tetrahydrocannabinol in the cannabis usually smoked |
| Cannabidiol (CBD) concentration | one year | Concentration of cannabidiol in the cannabis usually smoked |
Countries
France
Outcome results
None listed