A randomized clinical trial of low-dose cannabis extract in Alzheimer's disease.

BackgroundPreclinical and clinical evidence suggest that low-dose cannabinoids could ameliorate Alzheimer's disease (AD) signs and symptoms. We designed this trial to evaluate the safety and efficacy of low-dose THC-CBD balanced cannabinoid extract in the treatment of patients with AD-associated dementia.ObjectiveThe objective of this phase 2 trial was to evaluate the safety and efficacy of a balanced THC-CBD cannabinoid extract for symptomatic patients with AD.MethodsA Phase 2, randomized, double-blind, placebo-controlled, clinical trial including patients between 60 and 80 years-old diagnosed with AD-associated dementia. For 26 weeks, participants orally received either placebo or THC-CBD extract (0.350 mg/THC and 0.245 mg/CBD), daily.ResultsAt week 26, Mini-Mental State Exam total score was significantly higher in cannabis- when compared to placebo-treated patients, which was assessed using the mixed model analysis. No significant difference was detected between placebo and cannabis groups in terms of secondary outcomes and adverse events incidence.ConclusionsTo this date, this is the longest clinical trial evaluating cannabinoids effects on AD patients. We initially demonstrate that low-dose THC-CBD potentially can be an effective and safe therapeutic option for AD-related dementia. Nonetheless, larger and longer trials are necessary to confirm this finding and establish cannabinoid administration as therapy for AD dementia.Trial RegistrationThe Brazilian Registry of Clinical Trials (ReBEC) registration #U1111-1258-2058 - REBEC (ensaiosclinicos.gov.br).