Mental disorders represent a major global health problem, with depression being one of the most prevalent and disabling conditions worldwide. Growing evidence suggests that the serotonergic system, particularly the 5-HT2A receptor, plays an important role in modulating mood and cognitive processes, constituting a key pharmacological target for several psychoactive compounds. In this study, we...
PsychopharmacologyJuly 1, 2026Sarah Ann Smith, Haseeb Mohammad, Lik Hang N Lee et al.
Interest in psychedelic drugs has increased rapidly because of their potential therapeutic role in psychiatric disorders. Impairments in the sociocognitive skills needed to build and maintain social relationships are prominent features of many psychiatric and neurodevelopmental disorders. Emerging evidence suggests that compounds such as 3,4-methylenedioxymethamphetamine (MDMA), lysergic acid...
Psilocybin has been shown to induce fast and sustained symptoms improvements across various psychiatric conditions, yet its long-term mechanisms of action are not fully understood. Initial evidence suggests that longitudinal functional and structural brain changes implicate fronto-striatal-thalamic (FST) circuitry, a broad system involved in goal-directed behavior and motivational states. Here,...
Psilocybin is a serotonergic 5-HT 2A R agonist that causes psychedelic and anxiolytic effects in human users. To delineate conservation of psilocybin pharmacology, we investigated behavioral effects of psilocybin in planarians ( Dugesia dorotocephala ), the simplest living animal with cephalization that also has a well defined serotonin (5-hydroxytryptamine [5-HT]) system. We quantified...
Abstract Activation of mGluR2 (metabotropic glutamate receptor 2), the primary presynaptic autoreceptor for glutamate in the brain, is well established to attenuate the psychedelics-mediated behavioral and electrophysiological effects. However, the mechanisms responsible for these actions are controversial. The two competing mechanistic hypotheses have been proposed to explain this phenomenon...
Recent evidence reveals that several psychotropic compounds exert significant biological effects on the skin through neurochemical and immunomodulatory pathways. Cannabinoids such as tetrahydrocannabinol (THC) show potent anti-inflammatory, antipruritic, and anti-aging properties when applied topically, and may hold therapeutic potential. Antidepressants, particularly fluoxetine (Prozac), have...
The brain’s ability to rewire itself, neuroplasticity, declines dramatically with age. Children learn faster; adults get stuck in patterns; older adults struggle to adapt. The reasons for this decline remain unclear. In a companion paper (Solis, 2026a), I critically evaluated the broad hypothesis that N,N-dimethyltryptamine (DMT) has endogenous physiological functions. The evidence was found to...
The ongoing psychedelic renaissance has prompted a renewed search for novel drugs based on modifying existing psychedelic motifs. In this study, a synthesis of 4-bromo-N,N-dimethyltryptamine (4-Br-DMT) was achieved and used as a late-stage intermediate for analog development. Specifically, we were able to synthesize and access novel molecules by forming carbon–carbon bonds at the C4 position...
BACKGROUND: Major depressive disorder is one of the most debilitating psychiatric disorders worldwide. First-line treatments such as selective serotonin reuptake inhibitors have significant limitations, including delayed onset of therapeutic effects and treatment resistance in about 30% of patients. Increasing evidence suggests that acute administration of serotonergic psychedelics, such as...
The human body possesses enzymatic machinery to both synthesize and rapidly degrade N,N-dimethyltryptamine (DMT). This coexistence raises a question: does DMT serve an endogenous function, or is it a metabolic byproduct with no physiological role? DMT is structurally almost identical to serotonin and binds to the same serotonin receptors. Serotonin is universally accepted as a neurotransmitter...
Abstract Background Serotonin has been implicated in cognitive flexibility and pathological perseverative thinking (PT), including rumination, worry, and obsessions. However, evidence remains fragmented across pharmacological manipulations, clinical populations, and outcome measures. This multilevel meta-analysis examined whether serotonergic interventions influence PT and cognitive...
Serotonin (5-hydroxytryptamine; 5-HT) is a key neuromodulator involved in the regulation of mood, appetite, aggression, and impulse control. Dysregulation of central 5-HT function has been implicated in alcohol use disorder (AUD) and comorbid depression. This review summarizes clinical and preclinical evidence on the role of 5-HT in AUD development, heterogeneity, and treatment response....
This protocol describes a systematic review and meta-analysis assessing the efficacy and safety of classic serotonergic psychedelics and related serotonergic ergoline or lysergamide compounds in cluster headache and migraine. The review will include clinical studies evaluating psilocybin, psilocin, LSD, LSA, DMT/ayahuasca, mescaline, BOL-148 / 2-bromo-LSD / bromolysergide, lisuride,...
Autism Spectrum Disorder (ASD) is characterized by persistent social-communication deficits, cognitive rigidity, and atypical sensory processing. Current pharmacological treatments, including risperidone and aripiprazole, provide only limited symptomatic relief and do not address the underlying neurobiological mechanisms. Converging evidence implicates dysregulated serotonergic signaling,...
Abstract Rationale: Major depressive disorder (MDD) shows marked sex differences in prevalence, symptomatology, and treatment response. However, women remain underrepresented in many clinical trials, and sex-specific treatment outcomes are rarely examined. Objectives This study reanalyzed data from a randomized controlled trial comparing psilocybin and escitalopram for MDD to evaluate sex...
The aim of this study was to investigate the effects of deuterium substitution on the in vitro pharmacology of the psychedelic drug 2-(4-bromo-2,5-dimethoxyphenyl)ethan-1-amine (2C-B). Two deuterated isotopologues of 2C-B, namely 2-(4-bromo-5-methoxy-2-(methoxy-d3)phenyl)ethan-1-amine (2CB-2OCD3) and 2-(4-bromo-2-methoxy-5-(methoxy-d3)phenyl)ethan-1-amine (2CB-5OCD3), were synthesized and...
Traumatic brain injury (TBI) causes persistent neurobehavioral deficits and increases the risk of psychiatric disorders, including depression, anxiety, and cognitive dysfunction linked to disrupted neuroplasticity, neuroinflammation, and serotonergic (5-HT) signaling. No effective pharmacotherapies exist for chronic TBI. Psilocybin, a psychedelic 5-HT2A receptor agonist, shows promise due to...
NeuropharmacologyJune 11, 2026Vincenzo Crunelli, Tatiana P Morais, William M Connelly et al.
Renewed interest in psychedelic therapeutics has brought serotonin 5-HT2A receptors (5-HT2ARs) back into focus. Given the role of the thalamus in sensory integration and network synchronization, we examined the expression, developmental regulation, and functional impact of thalamic 5-HT2ARs, with particular emphasis on their interaction with extrasynaptic GABAA receptors and the generation of...
Provided herein are novel 5,6-bicyclic compounds as 5-HT2A receptor agonists, pharmaceutical compositions, use of such compounds in treating depression, anxiety, substance abuse and headaches, and processes for preparing such compounds.
New psychoactive substances (NPS) are a heterogeneous group of recreational drugs that mimic the actions and psychoactive effects of existing pharmaceutical products or recreational drugs. As NPS can be highly potent, even exceeding their template compound's potency, there are frequent reports of non-fatal and fatal intoxications. One principal target for hallucinogenic and psychedelic drugs,...