In 99 first-episode schizophrenia patients receiving long-acting injectable antipsychotics for 24 months, 21% experienced breakthrough psychosis, with cannabis use identified as an independent predictor.
Psychiatrists treating early psychosis, patients and families managing schizophrenia, substance use researchers.
21% had breakthrough psychosis; cannabis use was an independent predictor
What the researchers found
About 21% of patients developed breakthrough psychotic symptoms despite assured medication adherence via long-acting injections. Current cannabis use independently predicted breakthrough episodes, and post-breakthrough treatment response was poorer than the initial response.
Why it matters
By using long-acting injectable antipsychotics, this study removes non-adherence as a factor, showing that breakthrough psychosis occurs even with guaranteed medication delivery, and that cannabis use is a modifiable risk factor.
The numbers in context
99 patients (mean age 24.1, 73.7% male). 21 of 99 (21.2%) developed breakthrough psychosis after a mean of 17.4 months. Mean follow-up was 20 months.
How the study worked
Prospective cohort of 99 previously minimally treated first-episode schizophrenia-spectrum patients treated with long-acting injectable antipsychotics and followed for up to 24 months with regular assessments.
What this study cannot tell us
Relatively small sample of 99 patients from a single site. The association between cannabis use and breakthrough psychosis is observational and does not prove causation.
How to read the evidence
Moderate: prospective design with assured medication adherence, though limited by small sample and single site.
When this study was published
Published in 2020 in Schizophrenia Research.
The bigger picture
The finding that post-breakthrough treatment response was worse than the initial response suggests a possible link between breakthrough episodes and emerging treatment resistance, making prevention of these episodes all the more important.
Questions still open
- Would cannabis cessation programs reduce breakthrough psychosis rates? Is the link between breakthrough psychosis and blood lipid levels a meaningful biological signal or a confound?
Common questions
What is breakthrough psychosis?
How strong was the cannabis link?
Read the original research
Predictors of psychosis breakthrough during 24 months of long-acting antipsychotic maintenance treatment in first episode schizophrenia.
Schizophrenia research, 225, 55-62
Citation
Emsley, Robin; Asmal, Laila; Rubio, Jose M; Correll, Christoph U; Kane, John M. (2020). Predictors of psychosis breakthrough during 24 months of long-acting antipsychotic maintenance treatment in first episode schizophrenia.. Schizophrenia research, 225, 55-62. https://doi.org/10.1016/j.schres.2019.11.025
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