Does cannabis use affect how long psychosis goes untreated? | Research

The takeaway

A study of 62 first-episode psychosis patients found that cannabis use did not affect the duration of untreated psychosis, but both cannabis use and longer untreated periods were independently associated with more dissociative symptoms at onset and over time.

Clinicians involved in early psychosis intervention programs and researchers studying the intersection of substance use and untreated psychosis.

Cannabis and DUP: independent effects on dissociation

What the researchers found

Cannabis use did not significantly affect the duration of untreated psychosis (DUP). However, both cannabis use and longer DUP were independently associated with higher dissociative symptoms at onset and over the 6-month follow-up period. Longer DUP was associated with worse overall symptoms as expected.

Why it matters

Duration of untreated psychosis is one of the strongest predictors of long-term outcomes. Finding that cannabis independently contributes to dissociative symptoms, separate from DUP effects, suggests cannabis adds a distinct burden on top of treatment delay.

The numbers in context

62 FEP patients; cannabis did not affect DUP length; both cannabis and longer DUP independently associated with dissociative symptoms; effects persisted over 6 months

How the study worked

Prospective study of 62 FEP patients with and without CUD from Italian psychiatric hospitals (2014-2019). Divided by DUP duration. Assessed at treatment initiation, 3 months, and 6 months using PANSS, GAF, and DES-II.

What this study cannot tell us

Small sample (62 patients). Potential selection bias in treatment-seeking population. DUP is inherently difficult to measure accurately. Cannot determine if dissociative symptoms preceded or resulted from cannabis use.

How to read the evidence

Prospective design with 6-month follow-up but small sample and potential measurement challenges.

When this study was published

Published in 2021; the role of dissociation as a marker of cannabis-influenced psychosis is an emerging research area.

The bigger picture

The convergence of cannabis use and treatment delay on dissociative symptoms through independent pathways suggests that early intervention programs need to address both factors. Reducing DUP alone may not fully resolve the additional dissociative burden created by cannabis use.

Questions still open

Would addressing cannabis use during the untreated period improve outcomes independently of reducing DUP? Do dissociative symptoms serve as a marker for cannabis-influenced psychosis? Could screening for dissociation help identify cannabis-related cases?

Common questions

Does cannabis delay treatment for psychosis?

In this study, cannabis use did not affect how long psychosis went untreated before treatment began. However, both cannabis use and longer untreated periods independently contributed to more dissociative symptoms.

Why do dissociative symptoms matter?

Dissociation, including feeling detached from reality, may indicate a more complex form of psychosis. This study found it was elevated by both cannabis use and treatment delay, suggesting it could be a marker for worse outcomes.

Read the original research

Duration of Untreated Disorder and Cannabis Use: An Observational Study on a Cohort of Young Italian Patients Experiencing Psychotic Experiences and Dissociative Symptoms.

International journal of environmental research and public health, 18(23)

View on PubMed ↗Publisher’s paper ↗

Citation

Ricci, Valerio; Martinotti, Giovanni; Ceci, Franca; Chiappini, Stefania; Di Carlo, Francesco; Burkauskas, Julius; Susini, Ottavia; Luciani, Debora; Quattrone, Diego; De Berardis, Domenico; Pettorruso, Mauro; Maina, Giuseppe; Di Giannantonio, Massimo. (2021). Duration of Untreated Disorder and Cannabis Use: An Observational Study on a Cohort of Young Italian Patients Experiencing Psychotic Experiences and Dissociative Symptoms.. International journal of environmental research and public health, 18(23). https://doi.org/10.3390/ijerph182312632