Acute and long-term psychiatric consequences of synthetic cannabinoids and related novel psychoactive substances: A systematic review.
Valerio Ricci, Stefania Chiappini, Giovanni Martinotti, Giuseppe Maina
Psychiatry Research February 1, 2026 DOI: 10.1016/j.psychres.2026.117056 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Longitudinal Case report Peer reviewed |
|---|---|
| Key findings | The authors conclude that synthetic cannabinoids and related novel psychoactive substances may constitute a distinct toxicological class with enhanced psychiatric risks, potentially involving prolonged sequelae and severe neurological complications. Reported figures include longer hospitalizations for synthetic cannabinoid psychosis than cannabis psychosis (43.45 vs. 22.91 days), prolonged psychotic episodes beyond five months in about 30 percent of one case series, 63 percent rhabdomyolysis in a synthetic cathinone outbreak series, and roughly 15 percent fatality and 40 percent intensive care admission for NBOMe exposures. |
Abstract
Background: Novel psychoactive substances (NPS) represent an evolving public health threat, yet evidence on their acute and long-term psychiatric consequences remains limited.
Objective: To systematically review psychiatric and neurological consequences of NPS use across the full clinical spectrum, with primary focus on synthetic cannabinoids and related compounds, and to characterize differential risk patterns.
Methods: Following PRISMA 2020 guidelines, we searched six databases (January 2005-August 2025). Primary inclusion required longitudinal studies with ≥6-month psychiatric follow-up; supplementary inclusion encompassed severe acute complications or fatalities to characterize the full toxicity spectrum and avoid survivor bias. We employed narrative synthesis with thematic analysis by substance class, focusing primarily on synthetic cannabinoids (n = 28 studies), synthetic cathinones (n = 12), and hallucinogens (n = 8, primarily NBOMe compounds).
Results: Among 58 included studies, 28 (48.3 %) provided ≥6-month longitudinal follow-up, 22 (37.9 %) documented acute toxicity or fatalities, and 8 (13.8 %) mixed timeframes; 22 studies (37.9 %) were rated high quality. In one comparative cohort, hospitalizations for synthetic cannabinoid-related psychosis were markedly longer than for cannabis-related psychosis (43.45 vs. 22.91 days). In a case series, prolonged psychotic episodes beyond five months occurred in approximately 30 % of patients. Synthetic cathinone-related rhabdomyolysis rates reached 63 % in an outbreak series. NBOMe exposures were associated with fatality rates of approximately 15 % and Intensive Care admission rates of approximately 40 %.
Conclusions: Synthetic cannabinoids and related NPS may represent distinct toxicological class with enhanced psychiatric risks, potentially characterized by prolonged sequelae and severe neurological complications. Evidence suggests the need for clinical protocols, enhanced surveillance, and targeted prevention strategies.
Citations in the library
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and 14 more in the library