Cannabis ex-users with first-episode psychosis recovered attention closest to healthy levels over 3 years

Among 461 first-episode psychosis patients followed for 3 years, those who quit cannabis showed the most attention improvement, reaching scores closest to healthy controls.

Setién-Suero, Esther et al.·Schizophrenia research·2022·Strong EvidenceLongitudinal Cohort
RTHC-04213Longitudinal CohortStrong Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Longitudinal Cohort
Evidence
Strong Evidence
Sample
N=105

What This Study Found

Over 3 years, attention improved most in FEP patients who never used cannabis (n=238), followed by ex-users (n=105) and persistent users (n=43). At follow-up, ex-users achieved attention scores closest to those of healthy controls.

Key Numbers

648 total participants (461 patients, 187 controls). 35.3% were cannabis users (187 patients, 42 controls). At 3 years: never-users improved most, ex-users (n=105) reached scores closest to healthy controls, persistent users (n=43) improved least.

How They Did This

Longitudinal study of 461 FEP patients and 187 healthy controls. Cannabis use status categorized as never-user, ex-user, or persistent user. Neuropsychological attention tests administered at baseline and 3-year follow-up.

Why This Research Matters

This is one of the largest and longest studies to show that quitting cannabis after a first psychotic episode is associated with meaningful cognitive recovery, with former users ultimately performing near the level of healthy individuals.

The Bigger Picture

The finding that ex-users outperformed never-users in reaching healthy control levels at 3 years suggests that cognitive recovery after quitting cannabis may be particularly robust in this population.

What This Study Doesn't Tell Us

Observational design, so unmeasured factors may explain differences between groups. Cannabis use was categorized broadly without detailed frequency or potency data. Attrition over 3 years may introduce selection bias.

Questions This Raises

  • ?Why did ex-users reach scores closer to healthy controls than never-users?
  • ?Could it reflect a pre-existing cognitive advantage in those who used cannabis?
  • ?Does the timing of quitting relative to the psychotic episode matter?

Trust & Context

Key Stat:
Ex-users achieved attention scores closest to healthy controls at 3 years
Evidence Grade:
Strong: large sample (648 participants), 3-year longitudinal design, healthy control group, standardized neuropsychological assessment.
Study Age:
Published in 2022.
Original Title:
Longitudinal effects of cannabis use on attentional processes in patients with first episode of psychosis.
Published In:
Schizophrenia research, 244, 71-80 (2022)
Database ID:
RTHC-04213

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Follows a group of people over time to track how outcomes develop.

What do these levels mean? →

Frequently Asked Questions

How much did attention improve over 3 years?

All patient groups showed significant improvement, but never-users improved most, followed by ex-users, then persistent users. Patients still performed below healthy controls at all time points.

Did quitting cannabis fully restore attention?

Ex-users came closest to healthy control levels at 3 years, suggesting substantial but not necessarily complete recovery.

Were there attention differences at baseline?

Yes, all patient groups performed worse than controls at baseline, with cannabis users and non-users starting at similar levels.

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Cite This Study

RTHC-04213·https://rethinkthc.com/research/RTHC-04213

APA

Setién-Suero, Esther; Ayesa-Arriola, Rosa; Peña, Javier; Crespo-Facorro, Benedicto; Ojeda, Natalia. (2022). Longitudinal effects of cannabis use on attentional processes in patients with first episode of psychosis.. Schizophrenia research, 244, 71-80. https://doi.org/10.1016/j.schres.2022.05.011

MLA

Setién-Suero, Esther, et al. "Longitudinal effects of cannabis use on attentional processes in patients with first episode of psychosis.." Schizophrenia research, 2022. https://doi.org/10.1016/j.schres.2022.05.011

RethinkTHC

RethinkTHC Research Database. "Longitudinal effects of cannabis use on attentional processe..." RTHC-04213. Retrieved from https://rethinkthc.com/research/setien-suero-2022-longitudinal-effects-of-cannabis

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.