Among 106 psychiatric inpatients, 25.5% used cannabis the week before admission, with psychotic disorder patients showing the highest use prevalence and symptom severity.
Psychiatrists, emergency mental health clinicians, and substance use researchers.
25.5% used cannabis before admission; psychosis diagnosis was the main severity predictor
What the researchers found
Cannabis use the week before psychiatric admission (25.5% prevalence) showed a weak positive correlation with symptom severity (rs=0.28, p=0.03) in bivariate analysis, but was not an independent predictor in multivariate models. Psychotic disorder diagnosis and need for emergency antipsychotics/benzodiazepines were the significant predictors of severity.
Why it matters
Understanding the relationship between pre-admission cannabis use and psychiatric symptom severity helps clinicians assess risk and tailor treatment, particularly for psychosis patients.
The numbers in context
106 inpatients; 25.5% used cannabis before admission; mean BPRS 55.8 overall, 62.9 among cannabis users; weak correlation rs=0.28 between SJU and BPRS.
How the study worked
Cross-sectional study of 106 acute psychiatric inpatients, measuring cannabis use in Standard Joint Units (SJU) the week before admission and symptom severity via Brief Psychiatric Rating Scale (BPRS).
What this study cannot tell us
Small single-center sample; cross-sectional design; self-reported cannabis use; Standard Joint Units may not capture all forms of consumption; 25.5% prevalence may underestimate use.
How to read the evidence
Preliminary: small single-center cross-sectional study with self-reported cannabis use.
When this study was published
Published 2020.
The bigger picture
The study found that having a psychotic disorder, not cannabis use per se, was the main driver of symptom severity. Cannabis use may be a marker for psychosis risk rather than an independent cause of worse acute symptoms.
Questions still open
- Does reducing cannabis use before hospitalization improve acute outcomes? Would results differ in a larger, multi-center sample?
Common questions
Does cannabis use before hospitalization make psychiatric symptoms worse?
How common is cannabis use among psychiatric inpatients?
Read the original research
Cannabis use the week before admission to psychiatric in-patient service as a marker of severity.
Journal of psychiatric research, 129, 40-46
Citation
Madero, S; Oliveras, C; Pons, M T; Sague, M; López-Pelayo, H; Gual, A; Balcells, M. (2020). Cannabis use the week before admission to psychiatric in-patient service as a marker of severity.. Journal of psychiatric research, 129, 40-46. https://doi.org/10.1016/j.jpsychires.2020.05.028
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