Table 1:

Psychedelic agents currently under investigation for their potential benefits as adjuncts to psychotherapy

Substance	Derivation or chemical analogues	General effects and properties	Potential harms^*	Potential therapeutic uses^†
LSD	Ergot fungus (Claviceps purpurea); morning glory (Turbina corymbosa); Hawaiian baby woodrose (Argyreia nervosa) — sources of ergine or lysergic acid amide	5-HT_2A (serotonin) agonist of pyramidal neurons Dizziness, weakness, tremors, paresthesia Altered consciousness (visions, auditory distortions, ideations) Altered mood (happy, sad, fearful, irritable) Distorted sense of space, time	Psychosis Hallucinogen persisting perception disorder	Addiction (e.g., alcohol)3 Anxiety associated with terminal illness4,5
Psilocybin	Psilocybe and other genera of mushrooms (various species)	5-HT_2A (serotonin) agonist of pyramidal neurons Dizziness, weakness, tremors, paresthesia Altered consciousness (visions, auditory distortions, ideations) Altered mood (happy, sad, fearful, irritable) Distorted sense of space, time	Psychosis Hallucinogen persisting perception disorder	Addiction (tobacco, alcohol)6,7 Anxiety associated with terminal illness8
Ayahuasca brew (admixtures contain DMT)	Chacruna leaf (Psychotria viridis); Chagropanga vine (Diplopterys cabrerana); ayahuasca vine (Banisteriopsis caapi); assorted other admixture plants	5-HT_2A (serotonin) agonist of pyramidal neurons Dizziness, weakness, tremors, paresthesia Nausea, emesis Altered consciousness (visions, auditory distortions, ideations) Altered mood (happy, sad, fearful, irritable) Distorted sense of space, time	Psychosis Serotonin syndrome and other dangers from medication interactions due to monoamine oxidase inhibitory activity	Addiction (alcohol, cocaine, tobacco)9,10 Depression, anxiety11–14
Mescaline	Peyote cactus (Lophophora williamsii); San Pedro cactus (Echinopsis pachanoi)	5-HT_2A (serotonin) agonist of pyramidal neurons Dizziness, weakness, tremors, paresthesia Altered consciousness (visions, auditory distortions, ideations) Altered mood (happy, sad, fearful, irritable) Distorted sense of space, time	Psychosis	Addiction (alcohol)15
MDMA	Sassafras tree (Sassafras albidum) — source of safrole, precursor chemical	Serotonin, dopamine and noradrenaline agonist Euphoria Arousal Perceptual alteration Enhanced empathy and sociability	Potential neurocognitive deficits (e.g., memory impairment) Sleep disruption Short-term depression	PTSD16–18

Note: DMT = dimethyltryptamine, LSD = lysergic acid diethylamide, MDMA = methylenedioxymethamphetamine, PTSD = posttraumatic stress disorder.
↵* Potential harms identified here are associated with illicit and unsupervised nonmedical uses of psychedelic substances (often in the context of polysubstance use); current clinical studies on psychedelic agents have not reported such chronic adverse sequelae.
↵† Potential therapeutic uses are identified based on evidence from past (i.e., 1950s–1960s) and current research on psychedelic drugs.