Cannabis-Related Psychiatric Hospitalizations Rose Sharply in Switzerland Over Two Decades

A nationwide Swiss study found significant increases in cannabis-related psychiatric hospitalizations from 1998 to 2020, with the highest rates among 15-24 and 25-44 year olds.

Pfeifer, Philippe et al.·International journal of public health·2022·Strong EvidenceRetrospective Cohort
RTHC-04146Retrospective CohortStrong Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Retrospective Cohort
Evidence
Strong Evidence
Sample
Not reported

What This Study Found

Cannabis-related psychiatric hospitalization rates increased significantly from 1998 to 2020. These diagnoses were disproportionately represented in the 15-24 and 25-44 age groups compared to other psychiatric diagnoses. The trend was compared against alcohol-related and psychotic disorder hospitalizations.

Key Numbers

Data covered all psychiatric inpatients in Switzerland from 1998-2020. Cannabis-related diagnoses were significantly overrepresented in ages 15-24 and 25-44. The study documented a "sharp increase" in cannabis-related hospitalizations over the observation period.

How They Did This

Nationwide analysis using Swiss Federal Statistics Office data covering all psychiatric inpatient cases in Switzerland from 1998 to 2020. Trend analyses compared cannabis-related diagnoses to alcohol-related and psychotic disorder hospitalization rates by age group, gender, and region.

Why This Research Matters

Population-level hospitalization trends provide hard data on the public health impact of cannabis. The concentration in younger age groups aligns with neurobiological evidence about adolescent vulnerability and has direct implications for Swiss cannabis policy reform.

The Bigger Picture

Switzerland is actively considering cannabis regulation reform. This nationwide hospitalization data provides important context for policy decisions, showing that cannabis-related psychiatric burden has been growing independent of formal legalization.

What This Study Doesn't Tell Us

Hospitalization data may not capture the full picture, as many cannabis-related psychiatric issues are managed outpatient. Changes in diagnostic coding practices or clinician awareness could contribute to trend increases. Causation cannot be established from trend data alone.

Questions This Raises

  • ?Would regulated cannabis access with age restrictions and quality controls reduce psychiatric hospitalization rates?
  • ?Are the increasing trends driven by higher potency products, increased use, or better clinical recognition?

Trust & Context

Key Stat:
Sharp increase in cannabis psychiatric hospitalizations across 1998-2020
Evidence Grade:
Strong: nationwide data covering all psychiatric inpatients across 22 years from a federal statistics office.
Study Age:
Published in 2022, covering data from 1998-2020.
Original Title:
A Nationwide Study of Inpatient Case Rate Incidence of Cannabis-Related Diagnoses in Switzerland.
Published In:
International journal of public health, 67, 1605554 (2022)
Database ID:
RTHC-04146

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

Looks back at existing records to find patterns.

What do these levels mean? →

Frequently Asked Questions

Are more people being hospitalized for cannabis problems?

In Switzerland, yes. Nationwide data showed significant increases in cannabis-related psychiatric hospitalizations from 1998 to 2020, particularly among people aged 15-44.

Does this mean cannabis is more dangerous than before?

The study cannot determine whether the increase is due to more cannabis use, higher potency products, better clinical recognition, or changes in diagnostic practices. All of these factors may contribute.

Read More on RethinkTHC

Cite This Study

RTHC-04146·https://rethinkthc.com/research/RTHC-04146

APA

Pfeifer, Philippe; Auer, Reto; Baggio, Stéphanie; Moggi, Franz. (2022). A Nationwide Study of Inpatient Case Rate Incidence of Cannabis-Related Diagnoses in Switzerland.. International journal of public health, 67, 1605554. https://doi.org/10.3389/ijph.2022.1605554

MLA

Pfeifer, Philippe, et al. "A Nationwide Study of Inpatient Case Rate Incidence of Cannabis-Related Diagnoses in Switzerland.." International journal of public health, 2022. https://doi.org/10.3389/ijph.2022.1605554

RethinkTHC

RethinkTHC Research Database. "A Nationwide Study of Inpatient Case Rate Incidence of Canna..." RTHC-04146. Retrieved from https://rethinkthc.com/research/pfeifer-2022-a-nationwide-study-of

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.