Performance of schizophrenic patients in the Stroop Color Word Test and electrodermal responsiveness after acute administration of cannabidiol (CBD)
Jaime E. C. Hallak, João Paulo Machado‐de‐Sousa, José Alexandre S. Crippa, Rafael Faria Sanches, Clarissa Trzesniak, Cristiano Chaves, Sandra Aparecida Bernardo, Simone Cecílio Hallak Regalo, Antônio Waldo Zuardi
Brazilian Journal of Psychiatry March 1, 2010 DOI: 10.1590/s1516-44462010000100011 via OpenAlex
Summary
AI-generated from the abstractA single dose of cannabidiol (CBD) does not improve selective attention in people with schizophrenia, and higher doses may worsen performance. In a study of 28 patients, those given 600 mg of CBD performed worse on the Stroop Color Word Test than those given 300 mg or placebo, while all groups showed some improvement from practice. No differences were found in electrodermal responses to sounds. The authors suggest that chronic CBD administration might still be beneficial, but acute treatment appears ineffective for cognitive symptoms.
Study at a glance
| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Sample size | 28 |
| Population | Schizophrenic patients |
| Intervention | Cannabidiol |
| Dose | 300 mg or 600 mg |
| Duration | Two experimental sessions, single acute administration |
| Topics | Cannabis CBD |
| Keywords | Stroop effect Placebo Schizophrenia object-oriented programming Medicine |
| Citations | 122 |
| Key finding | Single acute doses of cannabidiol did not improve Stroop test performance in schizophrenic patients, and 600 mg was associated with worse performance compared to placebo or 300 mg. |
Abstract
OBJECTIVE: The last decade has seen increasing evidence of dysfunctions in the endogenous cannabinoid system in schizophrenia and of its relationship with the typical cognitive impairment of the disorder. Studies in animal models, healthy volunteers, and psychotic patients clearly suggest an antipsychotic-like effect of cannabidiol. This study investigated the effects of cannabidiol on selective attention in 28 schizophrenic patients using the Stroop Color Word Test and on these patients' electrodermal responsiveness to auditive stimuli. METHOD: The subjects attended two experimental sessions, the first one without the administration of drugs. In the second session the subjects were divided into three groups that received either a single dose of cannabidiol 300 mg or cannabidiol 600 mg or placebo. RESULTS: The three groups did not differ significantly with respect to electrodermal measures in the two experimental sessions. When the first and second sessions were compared improved performance was found in all three groups, with patients who received placebo and cannabidiol 300 mg performing better than those who received cannabidiol 600 mg. CONCLUSION: The single, acute administration of cannabidiol seems to have no beneficial effects on the performance of schizophrenic patients in the Stroop Color Word Test, although the hypothesis that chronic administration may lead to improvement cannot be disregarded.