Psychedelic drugs such as LSD (lysergic acid diethylamide), psilocybin and ketamine have been rediscovered by researchers in neuroscience and psychiatry. A recent review in the Journal of Psychopharmacology highlights the distinct therapeutic effects of psychedelics, as well as the current re-evaluation of their use in the treatment of addiction, anxiety in terminally ill patients, depression, cluster headaches and obsessive-compulsive disorder (OCD).A psychedelic drug is a psychoactive drug whose primary action is to alter cognition and perception. Since the discovery of LSD in 1943, psychedelic drugs have been of major scientific interest. Despite clinical psychedelic research coming to a standstill in the mid-1970s (due to regulatory restrictions), an increase in methodological quality standards, neurobiological method and neuroimaging, as well as interest in the interest of the neurosciences in subjective experience, has meant a re-emergence of interest.The review by Tomislav Majić (Charité University Medicine, Berlin), Timo Schmidt (Free University Berlin) and Jürgen Gallinat (University Medical Center Hamburg-Eppendorf), looked at current clinical research and re-evaluated former and recent concepts of where and how psychedelic substances exert their therapeutic effects. Share on Twitter Share on Facebook Email Pinterest LinkedIn Share Key findings included that ketamine is effective in the treatment of substance addiction, both through the psychedelic experiences and it’s enhancing of personal meaning and spiritual significance. Ketamine has also been used to produce short-term anti-depressive effects in major depression and bipolar disorder, through its altering of perception (It has also been proposed as a treatment option for affective disorders based on its pharmacological effects).LSD has been shown to be beneficial in the treatment of alcohol abuse when used in combination with therapy.Psilocybin, the main component of so-called magic mushrooms, has been recently shown to be effective in the treatment of anxiety in cancer patients, not by reducing pain, but by inducing feelings of strengthened rapport and relationships with close relatives and friends. Recent research has also highlighted the therapeutic use of LSD and psilocybin in treating cluster headaches. Interestingly, it was reported that the therapeutic effects appear to be completely independent of the psychedelic experience.The review reported converging evidence suggesting that serotonergic neurotransmission plays a key role in the mechanism of these psychedelic drugs – the neurotransmitter serotonin is thought to play an important role in the brain relating to mood, anxiety and happiness.The findings of the review concluded that psychedelic drugs are unique in the sense that they: have neurochemical and pharmacodynamics effects (e.g. in the treatment of depression and possibly OCD); support various types of psychotherapy (e.g. in the treatment of terminal illness); can be used to treat headaches or other pain syndromes; and they often result in spiritual experiences through which they can assist in therapy (e.g. in the treatment of substance addiction). Furthermore, in contrast to traditional psychiatric drugs, they are only to be taken once or a few times.The review highlights the potential for psychedelic drugs to be used in clinical settings, although more research is required to develop a deeper understanding of their therapeutic effects and how they work.