Anorexia nervosa is a severe psychiatric condition with few approved treatments. This paper describes how individuals with lived experience of anorexia nervosa helped shape a pilot study of psilocybin-assisted therapy through two online focus groups involving eleven people, and presents the protocol for that study at Imperial College London. Twenty female participants aged 21–65 with a body mass index of 15 kg/m² or above will receive three oral doses of psilocybin (up to 25 mg) over six weeks, supported by psychological preparation and integration, with a 12-month remote follow-up.
Obesity involves behavioral factors that traditional treatments often fail to address. Like addiction, a chronic energy-dense diet can disrupt dopaminergic reward circuits, making individuals habitually responsive to food cues despite negative health outcomes. Psychedelics such as psilocybin and LSD may reduce the top-down influence of maladaptive reward predictions on perception and attention, potentially opening a window of psychological flexibility. This could allow individuals to adopt new cognitive and behavioral strategies through assisted psychotherapy, encouraging beneficial changes in eating behavior. However, new research is needed to assess the potential efficacy of this approach for compulsive eating.
In a small pilot study, 21 women with anorexia nervosa received three doses of psilocybin (COMP360) over six weeks, combined with talk therapy and usual care. The treatment was well tolerated; common side effects were headache, nausea, and dizziness. Two serious adverse events (suicide attempts) occurred in one participant during the 6–12 month period. Eating disorder symptoms significantly improved at six months, and motivation to change improved at twelve months, though individual responses varied widely. The findings provide preliminary support for the feasibility and safety of psilocybin therapy in this population, but larger, more rigorous studies are needed.