Therapeutic applications of psychedelics for anxiety and depression

Abstract

Anxiety and depression are two very prevalent and costly mood disorders. The physiopathology of depression is a very discussed topic, and the predominant theories include the monoaminergic theory and genetic vulnerability. Anxiety, albeit an illness with physical symptoms, also has a contested physiopathology, the theories of which include neurotransmitters and hyperactivity in certain areas of the brain. Although antidepressant and anxiolytic medication is useful (a fact that has also been contested), it has a slow onset, many adverse effects, and some patients are resistant to treatment. Psychedelic substances are substances that create hallucinations through agonism to the 5HT2A receptors. The substances studied in this review, ayahuasca, psilocybin and LSD, have fascinated the scientific community and society at large for the past decades, and in the case of ayahuasca and psilocybin, for millennia. It has been demonstrated that these substances do not cause dependence and are generally safe, although certain lesser common but dangerous adverse effects demand further studies. In the last few decades, studies into psychedelic treatment for anxiety and depression have sprung up, as it would solve some current antidepressant treatment problems. Nowadays, clinical evidence of these therapies, however limited, is very promising: antidepressant and anxiolytic effects were demonstrated, lasting well beyond a single psychedelic dose. This encourages further clinical studies and perhaps approval of these therapies in special cases.