Three weekly infusions of ketamine (0.8 mg/kg) helped people with severe alcohol use disorder stay abstinent more days over six months than placebo infusions did. The ketamine group averaged 10.1% more days abstinent than the placebo group. Combining ketamine with mindfulness-based relapse prevention therapy produced the largest improvement, with 15.9% more abstinent days compared with placebo plus alcohol education. No serious adverse events occurred. Relapse rates did not differ significantly between ketamine and placebo groups. The findings suggest ketamine is safe and may support abstinence, especially when paired with psychological therapy.
Cannabis use during adolescence is considered a risk factor for psychosis, and animal studies indicate that THC, the psychoactive component, alters striatal dopamine transmission. This study compared striatal dopamine D2/D3 receptor availability in ten volunteers with a history of cannabis use and ten controls using PET scans. No significant differences in receptor availability were found between groups, nor any correlation with lifetime cannabis use frequency. However, limbic striatal receptor availability was ten percent lower in current nicotine smokers. These results suggest that, unlike other drugs of abuse, a history of cannabis use is not associated with changes in striatal dopamine D2/D3 receptor availability.
People with alcohol use disorder experience changes in consciousness from 0.8 mg/kg intravenous ketamine administration. Ketamine's effects remain broadly consistent across three repeated infusions. Reductions in alcohol consumption linked to ketamine do not appear to be caused by the acute psychoactive effects of the drug.