Study register · detailSystematic Review · Psychosis Risk · 2026
Acute and long-term psychiatric consequences of synthetic cannabinoids and related novel psychoactive substances: A systematic review.
Ricci et al.·Psychiatry researchImpact 4.1
No direction reportedGRADEModerate0 citations
Samplek = 58 Studien n = 12 Pat.
DesignSystematic Review
”Key finding
Synthetic cannabinoids were associated with longer psychosis-related hospital stays than conventional cannabis, as well as with psychotic episodes lasting more than five months in about 30 percent of cases.
Summary
Systematic review (PRISMA 2020) on psychiatric consequences of synthetic cannabinoids and novel psychoactive substances across k=58 studies; 28 studies (48.3%) with ≥6-month follow-up, 22 studies (37.9%) rated high quality. Hospitalizations for synthetic cannabinoid-associated psychosis were significantly longer than for cannabis psychosis (43.45 vs. 22.91 days). In one case series, prolonged psychotic episodes >5 months occurred in ~30% of patients. Synthetic cathinones were associated with a rhabdomyolysis rate of 63%; NBOMe substances with a fatality rate of ~15% and an ICU admission rate of ~40%.
SummarySystematic review of 58 studies on psychiatric and neurological consequences of novel psychoactive substances, with a focus on synthetic cannabinoids (28 studies).
Confidence in the evidence
Very lowLowModerateHigh
Moderate
The third of four GRADE levels, the effect estimate is probably reliable.
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.