The association between cannabis and psychosis is established, but the role of underlying genetics is unclear. We used data from the EU-GEI case-control study and UK Biobank to examine the independent and combined effect of heavy cannabis use and schizophrenia polygenic risk score (PRS) on risk for psychosis.

Genome-wide association study summary statistics from the Psychiatric Genomics Consortium and the Genomic Psychiatry Cohort were used to calculate schizophrenia and cannabis use disorder (CUD) PRS for 1098 participants from the EU-GEI study and 143600 from the UK Biobank. Both datasets had information on cannabis use.

In both samples, schizophrenia PRS and cannabis use independently increased risk of psychosis. Schizophrenia PRS was not associated with patterns of cannabis use in the EU-GEI cases or controls or UK Biobank cases. It was associated with lifetime and daily cannabis use among UK Biobank participants without psychosis, but the effect was substantially reduced when CUD PRS was included in the model. In the EU-GEI sample, regular users of high-potency cannabis had the highest odds of being a case independently of schizophrenia PRS (OR daily use high-potency cannabis adjusted for PRS = 5.09, 95% CI 3.08–8.43, p = 3.21 × 10−10). We found no evidence of interaction between schizophrenia PRS and patterns of cannabis use.

Regular use of high-potency cannabis remains a strong predictor of psychotic disorder independently of schizophrenia PRS, which does not seem to be associated with heavy cannabis use. These are important findings at a time of increasing use and potency of cannabis worldwide.

Medical problems are frequently encountered during electronic dance music (EDM) events.

There are uncertainties about the frequencies and severity of intoxications with different types of recreational drugs: ethanol, “classical” illicit party drugs, and new psychoactive substances (NPS).

Statistical data on the medical problems encountered during two editions of an indoor electronic dance event with around 30,000 attendants were retrieved from the Belgian Red Cross (Mechelen, Belgium) database. Data on drug use were prospectively collected from the patient (or a bystander), the clinical presentation, and/or toxicological screening.

In the on-site medical station, 487 patients were treated (265 in 2013 and 222 in 2014). The most frequent reasons were trauma (n=171), headache (n=36), gastro-intestinal problems (n=44), and intoxication (n=160). Sixty-nine patients were transferred to a hospital, including 53 with severe drug-related symptoms. Analysis of blood samples from 106 intoxicated patients detected ethanol in 91.5%, 3,4-methylenedioxymethamphetamine (MDMA) in 34.0%, cannabis in 30.2%, cocaine in 7.5%, amphetamine in 2.8%, and gamma-hydroxybutyric acid (GHB) in 0.9% of patients (alone or in combination). In only six of the MDMA-positive cases, MDMA was the sole substance found. In 2014, the neuroleptic drug clozapine was found in three cases and ketamine in one. Additional analyses for NPS were performed in 20 cases. Only in one agitated patient, the psychedelic phenethylamines 25B-NBOMe and 25C-NBOMe were found.

At this particular event, recreational drug abuse necessitated on-site medical treatment in one out of 350 attendants and a hospital transfer in one out of 1,000. Ethanol remains the most frequently abused (legal) drug, yet classical illicit recreational drugs are also frequently (co-) ingested. The most worrying observation was high-risk poly-drug use, especially among MDMA users. Regarding NPS, the number of cases was low and the clinical presentations were rather mild. It should be stressed that these observations only apply to this particular event and cannot be generalized to other EDM events.

CalleP , SundahlN , MaudensK , WilleSMR , Van SassenbroeckD , De GraeveK , GogaertS , De PaepeP , DevrieseD , ArnoG , BlanckaertP . Medical Emergencies Related to Ethanol and Illicit Drugs at an Annual, Nocturnal, Indoor, Electronic Dance Music Event. Prehosp Disaster Med. 2018;33(1):71–76.