←Psychosis
Study register · detail Fallserie (compassionate use) · Psychosis · 2009

Synthetic Δ-9-Tetrahydrocannabinol (Dronabinol) Can Improve the Symptoms of Schizophrenia

Schwarcz et al. ·Journal of Clinical Psychopharmacology Impact 1.6
Mixed GRADE Very low 62 citations
Samplen = 6 Pat.
Durationunclear
EndpointPsychotic symptoms
Blindingn.a.
DesignFallserie (compassionate use)
Cannabinoidthc
Routeoral
Key finding

In 4 of 6 treatment-refractory patients an improvement of schizophrenia symptoms was reported, of whom 3 showed a reduction of core psychotic symptoms; no clinically significant side effects mentioned.

Summary

n=6 treatment-refractory chronic schizophrenia patients with self-reported cannabis-induced improvement received dronabinol (synthetic Δ9-THC). 4 of 6 showed symptom improvement; in 3 of the 4 responders reduction of core psychotic symptoms (not merely nonspecific sedation). No clinically significant side effects.

P
PopulationTreatment-refractory patients with severe chronic schizophrenia and subjectively reported symptom improvement under cannabis use, n=6
I
InterventionDronabinol (synthetic Δ-9-THC), oral, dosage not specified
O
Outcome4 of 6 patients showed symptom improvement; in 3 of 4 responders reduction of core symptoms of psychosis, no clinically significant adverse events
Confidence in the evidence
Very low

The lowest GRADE level, the effect estimate remains uncertain.

Downgraded for
Imprecision
Quality profile
Sample size ★★★★★
Blinding —
Effect size Mixed
Citations / year ★★★★★
Authors
Schwarcz G, Karajgi B, McCarthy R
DOI 10.1097/jcp.0b013e3181a6bc3b↗
Design: Fallserie (compassionate use)
Share
Abstract
We are reporting improvement of symptoms of schizophrenia in a small group of patients who received the cannabinoid agonist dronabinol (synthetic Delta-9-tetrahydrocannabinol). Before this report, cannabinoids had usually been associated with worsening of psychotic symptoms. In a heuristic, compassionate use study, we found that 4 of 6 treatment-refractory patients with severe chronic schizophrenia but who had a self-reported history of improving with Cannabis abuse improved with dronabinol. This improvement seems to have been a reduction of core psychotic symptoms in 3 of the 4 responders and not just nonspecific calming. There were no clinically significant adverse effects. These results complement the recent finding that the cannabinoid blocker rimonabant does not improve schizophrenic symptoms and suggest that the role of cannabinoids in psychosis may be more complex than previously thought. They open a possible new role for cannabinoids in the treatment of schizophrenia.
Indication
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