After decades of limited use, psychedelic compounds are reemerging as potential treatments for mental disorders that do not respond to existing therapies. This narrative review examines the current clinical and regulatory landscape of psychedelic-assisted therapies, covering ketamine, esketamine, MDMA, psilocybin, LSD, DMT, 5-MeO-DMT, and ibogaine for conditions like major depressive disorder, PTSD, and substance use disorders. The authors argue that these therapies will not follow standard prescription models but require specialist-delivered, psychotherapy-integrated care. Late-stage trials show promise for high-need populations, but unresolved challenges around long-term safety, scalability, workforce training, equity of access, and legal accountability remain.
Sensory deprivation—reduced or absent input across one or more senses—triggers widespread brain changes involving dopamine pathways, stress hormone dysregulation, immune activation, circadian rhythm disruption, and structural alterations in the hippocampus. These changes increase vulnerability to depression, anxiety, hallucinations, dissociative symptoms, and cognitive impairment. Outcomes depend on duration, whether the deprivation is voluntary, and individual factors such as baseline resilience, trait anxiety, and psychiatric history. However, short-term voluntary sensory restriction, such as Floatation-REST, may promote relaxation and emotional regulation under specific conditions. Understanding these mechanisms is relevant for clinical practice and for developing preventive strategies in extreme environments like long-duration space missions.