Anorexia nervosa is difficult to treat, especially in severe and enduring cases. Malnutrition and weight loss can reduce grey and white matter in the brain, impair neuroplasticity and neurogenesis, and cause difficulties with cognitive flexibility, memory, and learning. Depression is highly comorbid and may hinder recovery, but traditional antidepressants are often ineffective in underweight patients. This review presents a conceptual overview for treating anorexia nervosa with ketamine. Ketamine has rapid antidepressant effects hypothesized to occur via increased glutamate, leading to increased neuroplasticity, neurogenesis, and synaptogenesis. The article covers ketamine's use for common psychiatric comorbidities and discusses safety concerns. There appears ample theoretical background to warrant exploring ketamine as a treatment for adults with anorexia nervosa.
Ayahuasca, a South American psychoactive plant brew used in traditional spiritual and cultural rituals, has been studied primarily for the prevention of deamination of N,N-dimethyltryptamine (DMT) by monoamine oxidase inhibitors (MAOIs) in the brew. Two constituents, DMT and harmine, have received more research attention than secondary harmala alkaloids. Current evidence suggests that the pharmacological interactions in ayahuasca may act synergistically or additively to produce psychoactive effects, but the understanding of these synergistic mechanisms is limited and more complex processes may be involved. There is not yet enough data to determine any potential synergistic interaction between the known compounds, and increased pharmacological understanding is needed to avoid potential risks.