Anxiety and Affective Symptoms Related to the Use of Classic Psychedelics: A Systematic Review.

There is a large and rapidly growing body of literature investigating the therapeutic effects of classic psychedelics in affective and anxiety disorders, but very few studies have examined the inverse of this, that is, the potential for psychedelics to inflict anxiety and affective symptoms. A systematic literature search was performed and 39 papers were included in the final review to qualitatively synthesize the current literature on anxiety and affective disorders related to the use of classic psychedelics. Persisting disorders were less frequent but generally occurred in individuals who presented with several risk factors (overdose, polydrug use, unstructured recreational setting, psychosocial stress, personal/familial psychiatric histories). When psychedelics were administered in clinical studies under the framework of psychedelic-assisted therapy, the incidence of enduring anxiety and affective symptoms was low. In most cases, acute transient anxiety emerged and resolved during the dosing session without the need for additional treatment interventions. The nuance of such cases is discussed, shedding light on the role of emotional catharsis in the therapeutic process. Several suggestions are proposed to enhance patient safety including strengthening the therapeutic alliance, ensuring adequate mental preparation, acclimating to high doses and providing on-going therapeutic support.