Cannabis use and psychosis Mental and Behavioural Disorders Mental and behavioural disorders due to use of cannabinoids
Conditions
Interventions
Cannabis user and non-user non-naïve control participants will receive each of the following five conditions in randomised order, administered through a vaporiser
1. Tetrahydrocannabi
Sponsors
University of Wollongong (Australia)
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: Cannabis user group 1. Cannabis use for at least 3 years, and at least 4 times a month. 2. All participants must be between 18 and 55 years of age. Control group 1. Cannabis use at least 5 times but less than 20 times in total across lifetime; and for those participants only having used 5-10 times, they must have used at least once in the last 2 years; while for those participants having used between 10 and 20 times, the most recent exposure must not have been more than 10 years ago. No cannabis use in the past 3 months. 2. All participants must be between 18 and 55 years of age.
Exclusion criteria
Exclusion criteria: Cannabis user group 1. Daily cannabis use, or use of any illicit substance more than once a month for a period of six months 2. Head injury resulting in trauma to the brain, prolonged unconsciousness or concussion or required surgery, prolonged hospitalisation or rehabilitation 3. Medical diagnosis that would interfere with EEG testing (epilepsy, stroke, brain tumour, HIV positive, Hepatitis B or C, meningitis, encephalitis, MS, microcephaly), or a medical diagnosis contraindicated for cannabis exposure (e.g. asthma, cardiovascular disease, untreated hypertension). 4. Co-ingestion / concurrent use of medicines or drugs which will interfere with testing or are contraindicated for cannabis exposure (e.g. antipsychotics, antidepressants, benzodiazepines, amphetamines, opioids, alcohol). 5. A Body Mass Index (BMI) of less than 18 kg/m2 or more than 28 kg/m2. 6. A history of anaemia 7. Pregnancy 8. A current diagnosis of a psychotic disorder, or a score of 50 or more on the Community Assessment of Psychic Experiences. A first degree family member with psychotic diagnosis. 9. Use of any illicit substance (other than cannabis) in the 14 days prior to testing. 10. Meets DSM-IV criteria for dependence on alcohol or drugs other than cannabis; history of treatment for substance use problems other than cannabis. Control group 1. Use of any illicit substance more than once a month for a period of six months. 2. Head injury resulting in trauma to the brain, prolonged unconsciousness or concussion or required surgery, prolonged hospitalisation or rehabilitation. 3. Medical diagnosis that would interfere with EEG testing (epilepsy, stroke, brain tumour, HIV positive, Hepatitis B or C, meningitis, encephalitis, MS, microcephaly), or a medical diagnosis contraindicated for cannabis exposure (e.g. asthma, cardiovascular disease, untreated hypertension). 4. Co-ingestion /concurrent use of medicines or drugs which will interfere with testing or are contraindicated for cannabis exposure (e.g. antipsychotics, antidepressants, benzodiazepines, amphetamines, opioids, alcohol). 5. A body Mass Index (BMI) of less than 18 kg/m2 or more than 28 kg/m2. 6. A history of anaemia. 7. Pregnancy 8. A current diagnosis of a psychotic disorder, or a score of 50 or more on the Community Assessment of Psychic Experiences. 9. A first degree family member with psychotic diagnosis. Use of any illicit substance (other than cannabis) in the 14 days prior to testing. 10. Meets DSM-IV criteria for dependence on alcohol or drugs or a history of treatment for substance use problems.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The effect of THC and CBD on MMN amplitude recorded immediately following drug administration | — |
Secondary
| Measure | Time frame |
|---|---|
| The effect of THC and CBD on 1. Other EEG/ERP measures including P50 and resting state EEG 2. Neuropsychological measures including CogState battery of tests 3. Psychotic-like symptoms as indicated on a visual analogue scale, the Psychotomimetic States Inventory and the Clinician Administered Dissociative States Scale. 4. The potential moderating effect of specific genetic polymorphisms on THC and CBD (alone and in combination) effects on the MMN and other EEG/ERP and neuropsychological measures. | — |
Countries
Australia
Outcome results
None listed