1
|
Powers A, Angelos PA, Bond A, Farina E, Fredericks C, Gandhi J, Greenwald M, Hernandez-Busot G, Hosein G, Kelley M, Mourgues C, Palmer W, Rodriguez-Sanchez J, Seabury R, Toribio S, Vin R, Weleff J, Woods S, Benrimoh D. A computational account of the development and evolution of psychotic symptoms. Biol Psychiatry 2024:S0006-3223(24)01584-1. [PMID: 39260466 DOI: 10.1016/j.biopsych.2024.08.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 08/08/2024] [Accepted: 08/13/2024] [Indexed: 09/13/2024]
Abstract
The mechanisms of psychotic symptoms like hallucinations and delusions are often investigated in fully-formed illness, well after symptoms emerge. These investigations have yielded key insights, but are not well-positioned to reveal the dynamic forces underlying symptom formation itself. Understanding symptom development over time would allow us to identify steps in the pathophysiological process leading to psychosis, shifting the focus of psychiatric intervention from symptom alleviation to prevention. We propose a model for understanding the emergence of psychotic symptoms within the context of an adaptive, developing neural system. We will make the case for a pathophysiological process that begins with cortical hyperexcitability and bottom-up noise transmission, which engenders inappropriate belief formation via aberrant prediction error signaling. We will argue that this bottom-up noise drives learning about the (im)precision of new incoming sensory information because of diminished signal-to-noise ratio, causing a compensatory relative over-reliance on prior beliefs. This over-reliance on priors predisposes to hallucinations and covaries with hallucination severity. An over-reliance on priors may also lead to increased conviction in the beliefs generated by bottom-up noise and drive movement toward conversion to psychosis. We will identify predictions of our model at each stage, examine evidence to support or refute those predictions, and propose experiments that could falsify or help select between alternative elements of the overall model. Nesting computational abnormalities within longitudinal development allows us to account for hidden dynamics among the mechanisms driving symptom formation and to view established symptomatology as a point of equilibrium among competing biological forces.
Collapse
Affiliation(s)
- Albert Powers
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA.
| | - P A Angelos
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Alexandria Bond
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Emily Farina
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Carolyn Fredericks
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Jay Gandhi
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Maximillian Greenwald
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | | | - Gabriel Hosein
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Megan Kelley
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Catalina Mourgues
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - William Palmer
- Yale University Department of Psychology, New Haven, CT, USA
| | | | - Rashina Seabury
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Silmilly Toribio
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Raina Vin
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Jeremy Weleff
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - Scott Woods
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, USA
| | - David Benrimoh
- Department of Psychiatry, McGill University, Montreal, Canada
| |
Collapse
|
2
|
Campanale A, Inserra A, Comai S. Therapeutic modulation of the kynurenine pathway in severe mental illness and comorbidities: A potential role for serotonergic psychedelics. Prog Neuropsychopharmacol Biol Psychiatry 2024; 134:111058. [PMID: 38885875 DOI: 10.1016/j.pnpbp.2024.111058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 05/15/2024] [Accepted: 06/14/2024] [Indexed: 06/20/2024]
Abstract
Mounting evidence points towards a crucial role of the kynurenine pathway (KP) in the altered gut-brain axis (GBA) balance in severe mental illness (SMI, namely depression, bipolar disorder, and schizophrenia) and cardiometabolic comorbidities. Preliminary evidence shows that serotonergic psychedelics and their analogues may hold therapeutic potential in addressing the altered KP in the dysregulated GBA in SMI and comorbidities. In fact, aside from their effects on mood, psychedelics elicit therapeutic improvement in preclinical models of obesity, metabolic syndrome, and vascular inflammation, which are highly comorbid with SMI. Here, we review the literature on the therapeutic modulation of the KP in the dysregulated GBA in SMI and comorbidities, and the potential application of psychedelics to address the altered KP in the brain and systemic dysfunction underlying SMI and comorbidities. Psychedelics might therapeutically modulate the KP in the altered GBA in SMI and comorbidities either directly, via altering the metabolic pathway by influencing the rate-limiting enzymes of the KP and affecting the levels of available tryptophan, or indirectly, by affecting the gut microbiome, gut metabolome, metabolism, and the immune system. Despite promising preliminary evidence, the mechanisms and outcomes of the KP modulation with psychedelics in SMI and systemic comorbidities remain largely unknown and require further investigation. Several concerns are discussed surrounding the potential side effects of this approach in specific cohorts of individuals with SMI and systemic comorbidities.
Collapse
Affiliation(s)
| | - Antonio Inserra
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Stefano Comai
- Department of Psychiatry, McGill University, Montreal, QC, Canada; Department of Pharmaceutical and Pharmacological Sciences, University of Padova, PD, Italy.; IRCCS San Raffaele Scientific Institute, Milan, Italy; Department of Biomedical Sciences, University of Padua, Padua, Italy.
| |
Collapse
|
3
|
Brouwer A, Carhart‐Harris RL, Raison CL. Psychotomimetic compensation versus sensitization. Pharmacol Res Perspect 2024; 12:e1217. [PMID: 38923845 PMCID: PMC11194300 DOI: 10.1002/prp2.1217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 05/08/2024] [Indexed: 06/28/2024] Open
Abstract
It is a paradox that psychotomimetic drugs can relieve symptoms that increase risk of and cooccur with psychosis, such as attention and motivational deficits (e.g., amphetamines), pain (e.g., cannabis) and symptoms of depression (e.g., psychedelics, dissociatives). We introduce the ideas of psychotomimetic compensation and psychotomimetic sensitization to explain this paradox. Psychotomimetic compensation refers to a short-term stressor or drug-induced compensation against stress that is facilitated by engagement of neurotransmitter/modulator systems (endocannabinoid, serotonergic, glutamatergic and dopaminergic) that mediate the effects of common psychotomimetic drugs. Psychotomimetic sensitization occurs after repeated exposure to stress and/or drugs and is evidenced by the gradual intensification and increase of psychotic-like experiences over time. Theoretical and practical implications of this model are discussed.
Collapse
Affiliation(s)
- Ari Brouwer
- Department of Human Development and Family Studies, School of Human EcologyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Robin L. Carhart‐Harris
- Department of Neurology and PsychiatryUniversity of California San FranciscoSan FranciscoCaliforniaUSA
| | - Charles L. Raison
- Department of Psychiatry, School of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
- Vail Health Behavioral Health Innovation CenterVailColoradoUSA
- Center for the Study of Human HealthEmory UniversityAtlantaGeorgiaUSA
- Department of Spiritual HealthEmory University Woodruff Health Sciences CenterAtlantaGeorgiaUSA
| |
Collapse
|
4
|
Szafoni S, Gręblowski P, Grabowska K, Więckiewicz G. Unlocking the healing power of psilocybin: an overview of the role of psilocybin therapy in major depressive disorder, obsessive-compulsive disorder and substance use disorder. Front Psychiatry 2024; 15:1406888. [PMID: 38919636 PMCID: PMC11196758 DOI: 10.3389/fpsyt.2024.1406888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 05/21/2024] [Indexed: 06/27/2024] Open
Abstract
Resistance to traditional treatment methods is still a major obstacle in modern psychiatry. As a result, several studies are currently being conducted to find effective alternatives to traditional therapies. One of these alternatives is psilocybin, a psychedelic substance that has been tested in clinical trials as an adjunct to psychotherapy. These studies focus on patients with major depressive disorder (MDD), obsessive-compulsive disorder (OCD) and substance use disorder (SUD), particularly alcohol and nicotine dependence. This article looks at the current understanding of psilocybin, including data from clinical trials conducted, psilocybin's mechanism of action, its safety and the level of risk associated with it.
Collapse
Affiliation(s)
- Sandra Szafoni
- Students’ Scientific Circle in Department of Psychiatry, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
| | - Piotr Gręblowski
- Students’ Scientific Circle in Department of Psychiatry, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
| | - Klaudia Grabowska
- Students’ Scientific Circle in Department of Psychiatry, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
| | - Gniewko Więckiewicz
- Department of Psychiatry, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
| |
Collapse
|
5
|
Marrocu A, Kettner H, Weiss B, Zeifman RJ, Erritzoe D, Carhart-Harris RL. Psychiatric risks for worsened mental health after psychedelic use. J Psychopharmacol 2024; 38:225-235. [PMID: 38491857 PMCID: PMC10944581 DOI: 10.1177/02698811241232548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
BACKGROUND Resurgent psychedelic research has largely supported the safety and efficacy of psychedelic therapy for the treatment of various psychiatric disorders. As psychedelic use and therapy increase in prevalence, so does the importance of understanding associated risks. Cases of prolonged negative psychological responses to psychedelic therapy seem to be rare; however, studies are limited by biases and small sample sizes. The current analytical approach was motivated by the question of whether rare but significant adverse effects have been under-sampled in psychedelic research studies. METHODS A "bottom margin analysis" approach was taken to focus on negative responders to psychedelic use in a pool of naturalistic, observational prospective studies (N = 807). We define "negative response" by a clinically meaningful decline in a generic index of mental health, that is, one standard error from the mean decrease in psychological well-being 4 weeks post-psychedelic use (vs pre-use baseline). We then assessed whether a history of diagnosed mental illness can predict negative responses. RESULTS We find that 16% of the cohort falls into the "negative responder" subset. Parsing the sample by self-reported history of psychiatric diagnoses, results revealed a disproportionate prevalence of negative responses among those reporting a prior personality disorder diagnosis (31%). One multivariate regression model indicated a greater than four-fold elevated risk of adverse psychological responses to psychedelics in the personality disorder subsample (b = 1.425, p < 0.05). CONCLUSION We infer that the presence of a personality disorder may represent an elevated risk for psychedelic use and hypothesize that the importance of psychological support and good therapeutic alliance may be increased in this population.
Collapse
Affiliation(s)
- Alessia Marrocu
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Hannes Kettner
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Brandon Weiss
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Richard J Zeifman
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- NYU Langone Center for Psychedelic Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - David Erritzoe
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Robin L Carhart-Harris
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Carhart-Harris Lab, Departments of Neurology and Psychiatry, University of California San Francisco, San Francisco, CA, USA
| |
Collapse
|
6
|
Heresco-Levy U, Lerer B. Synergistic psychedelic - NMDAR modulator treatment for neuropsychiatric disorders. Mol Psychiatry 2024; 29:146-152. [PMID: 37945694 DOI: 10.1038/s41380-023-02312-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 10/17/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023]
Abstract
Modern research data suggest a therapeutic role for serotonergic psychedelics in depression and other neuropsychiatric disorders, although psychotomimetic effects may limit their widespread utilization. Serotonergic psychedelics enhance neuroplasticity via serotonin 2 A receptors (5HT2AR) activation and complex serotonergic-glutamatergic interactions involving the ionotropic glutamate receptors, tropomyosin receptor kinase B (TrkB) and the mammalian target of rapamycin (mTOR). N-methyl-d-aspartate receptors (NMDAR) channel antagonists, i.e. ketamine, and glycine modulatory site full and partial agonists, i.e., D-serine (DSR) and D-cycloserine (DCS), share some of these mechanisms of action and have neuroplastic and antidepressant effects. Moreover, procognitive effects have been reported for DSR and DCS and 5HT2AR-NMDAR interactions modulate neuronal excitability in prefrontal cortex and represent a target for new antipsychotics. We hypothesize that the synchronous administration of a psychedelic and a NMDAR modulator may increase the therapeutic impact of each of the treatment components and allow for dose adjustments and improved safety. We propose to initially focus research on the acute concurrent administration of psilocybin and DSR or DCS in depression.
Collapse
Affiliation(s)
- Uriel Heresco-Levy
- Department of Psychiatry, Herzog Medical Center; Hebrew University Faculty of Medicine, Jerusalem, Israel.
| | - Bernard Lerer
- Hadassah BrainLabs, Center for Psychedelic Research, Hadassah Medical Center, Hebrew University, Jerusalem, Israel.
| |
Collapse
|
7
|
Xu Z, Guo L, Yu J, Shen S, Wu C, Zhang W, Zhao C, Deng Y, Tian X, Feng Y, Hou H, Su L, Wang H, Guo S, Wang H, Wang K, Chen P, Zhao J, Zhang X, Yong X, Cheng L, Liu L, Yang S, Yang F, Wang X, Yu X, Xu Y, Sun JP, Yan W, Shao Z. Ligand recognition and G-protein coupling of trace amine receptor TAAR1. Nature 2023; 624:672-681. [PMID: 37935376 DOI: 10.1038/s41586-023-06804-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/31/2023] [Indexed: 11/09/2023]
Abstract
Trace-amine-associated receptors (TAARs), a group of biogenic amine receptors, have essential roles in neurological and metabolic homeostasis1. They recognize diverse endogenous trace amines and subsequently activate a range of G-protein-subtype signalling pathways2,3. Notably, TAAR1 has emerged as a promising therapeutic target for treating psychiatric disorders4,5. However, the molecular mechanisms underlying its ability to recognize different ligands remain largely unclear. Here we present nine cryo-electron microscopy structures, with eight showing human and mouse TAAR1 in a complex with an array of ligands, including the endogenous 3-iodothyronamine, two antipsychotic agents, the psychoactive drug amphetamine and two identified catecholamine agonists, and one showing 5-HT1AR in a complex with an antipsychotic agent. These structures reveal a rigid consensus binding motif in TAAR1 that binds to endogenous trace amine stimuli and two extended binding pockets that accommodate diverse chemotypes. Combined with mutational analysis, functional assays and molecular dynamic simulations, we elucidate the structural basis of drug polypharmacology and identify the species-specific differences between human and mouse TAAR1. Our study provides insights into the mechanism of ligand recognition and G-protein selectivity by TAAR1, which may help in the discovery of ligands or therapeutic strategies for neurological and metabolic disorders.
Collapse
Affiliation(s)
- Zheng Xu
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
- Frontiers Medical Center, Tianfu Jincheng Laboratory, Chengdu, China
| | - Lulu Guo
- Advanced Medical Research Institute, Meili Lake Translational Research Park, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Jingjing Yu
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Siyuan Shen
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Chao Wu
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Weifeng Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Shandong University, Jinan, China
| | - Chang Zhao
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yue Deng
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaowen Tian
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yuying Feng
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Hanlin Hou
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Lantian Su
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Hongshuang Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China
| | - Shuo Guo
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Heli Wang
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Kexin Wang
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Peipei Chen
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Jie Zhao
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
- Frontiers Medical Center, Tianfu Jincheng Laboratory, Chengdu, China
| | - Xiaoyu Zhang
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xihao Yong
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Lin Cheng
- Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Lunxu Liu
- Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Shengyong Yang
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Fan Yang
- Advanced Medical Research Institute, Meili Lake Translational Research Park, Cheeloo College of Medicine, Shandong University, Jinan, China
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China
| | - Xiaohui Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, China
- Beijing National Laboratory for Molecular Sciences, Beijing, China
| | - Xiao Yu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Shandong University, Jinan, China.
| | - Yunfei Xu
- Department of General Surgery, Qilu Hospital of Shandong University, Jinan, China.
| | - Jin-Peng Sun
- Advanced Medical Research Institute, Meili Lake Translational Research Park, Cheeloo College of Medicine, Shandong University, Jinan, China.
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, China.
| | - Wei Yan
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
| | - Zhenhua Shao
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
- Frontiers Medical Center, Tianfu Jincheng Laboratory, Chengdu, China.
| |
Collapse
|
8
|
Maćkowiak M. Psychedelics action and schizophrenia. Pharmacol Rep 2023; 75:1350-1361. [PMID: 37899392 PMCID: PMC10661800 DOI: 10.1007/s43440-023-00546-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/09/2023] [Accepted: 10/16/2023] [Indexed: 10/31/2023]
Abstract
Psychedelics are compounds acting by serotonin 5-hydroxytryptamine (5-HT)2A receptor activation and induce several behavioral responses. They are of special interest because of their positive effects on neuropsychiatric disorders (depression and posttraumatic stress disorder). However, several findings revealed that some psychedelic actions are similar to symptoms observed in schizophrenia (psychosis, sensorimotor gating impairments, attention, and working memory deficits) which might limit their clinical applications. Psychedelics activate some neurotransmitters, i.e., serotonergic, and glutamatergic, that are also impaired in schizophrenia. Therefore, the neurobiological background of psychedelics and schizophrenia is partially similar. Another important aspect to discuss is the perspective of using psychedelics in schizophrenia therapy. Postmortem studies showed a loss of synapses in schizophrenia, and the positive effects of psychedelics on neuroplasticity (synaptogenesis, neurogenesis, and neuritogenesis) might be essential in the context of schizophrenia therapy. However, because of psychedelics' psychotic action, the recommended doses of psychedelics in schizophrenia treatment are not established, and subpsychedelic dosing or microdosing are considered. Exploratory studies are needed to determine the tolerability of treatment and appropriate dosing regimen. Another therapeutic option is using non-hallucinogenic psychedelic analogs that also induce neuroplastic outcomes but do not have psychotogenic effects. Further preclinical and clinical studies are needed to recognize the potential effectiveness of 5-HT2A agonists in schizophrenia therapy.
Collapse
Affiliation(s)
- Marzena Maćkowiak
- Laboratory of Pharmacology and Brain Biostructure, Pharmacology Department, Maj Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
| |
Collapse
|
9
|
Bershad AK, de Wit H. Social Psychopharmacology: Novel Approaches to Treat Deficits in Social Motivation in Schizophrenia. Schizophr Bull 2023; 49:1161-1173. [PMID: 37358825 PMCID: PMC10483474 DOI: 10.1093/schbul/sbad094] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
BACKGROUND AND HYPOTHESIS Diminished social motivation is a negative symptom of schizophrenia and leads to severe functional consequences for many patients suffering from the illness. However, there are no effective medications available to treat this symptom. Despite the lack of approved treatments for patients, there is a growing body of literature on the effects of several classes of drugs on social motivation in healthy volunteers that may be relevant to patients. The aim of this review is to synthesize these results in an effort to identify novel directions for the development of medications to treat reduced social motivation in schizophrenia. STUDY DESIGN In this article, we review pharmacologic challenge studies addressing the acute effects of psychoactive drugs on social motivation in healthy volunteers and consider how these findings may be applied to deficits in social motivation in schizophrenia. We include studies testing amphetamines and 3,4-methylenedioxymethamphetamine (MDMA), opioids, cannabis, serotonergic psychedelics, antidepressants, benzodiazepines, and neuropeptides. STUDY RESULTS We report that amphetamines, MDMA, and some opioid medications enhance social motivation in healthy adults and may represent promising avenues of investigation in schizophrenia. CONCLUSIONS Given the acute effects of these drugs on behavioral and performance-based measures of social motivation in healthy volunteers, they may be particularly beneficial as an adjunct to psychosocial training programs in patient populations. It remains to be determined how these medications affect patients with deficits in social motivation, and in which contexts they may be most effectively administered.
Collapse
Affiliation(s)
- Anya K Bershad
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles Semel Institute for Neuroscience and Human Behavior, Los Angeles, CAUSA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, ILUSA
| |
Collapse
|
10
|
Jaster AM, González-Maeso J. Mechanisms and molecular targets surrounding the potential therapeutic effects of psychedelics. Mol Psychiatry 2023; 28:3595-3612. [PMID: 37759040 DOI: 10.1038/s41380-023-02274-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023]
Abstract
Psychedelics, also known as classical hallucinogens, have been investigated for decades due to their potential therapeutic effects in the treatment of neuropsychiatric and substance use disorders. The results from clinical trials have shown promise for the use of psychedelics to alleviate symptoms of depression and anxiety, as well as to promote substantial decreases in the use of nicotine and alcohol. While these studies provide compelling evidence for the powerful subjective experience and prolonged therapeutic adaptations, the underlying molecular reasons for these robust and clinically meaningful improvements are still poorly understood. Preclinical studies assessing the targets and circuitry of the post-acute effects of classical psychedelics are ongoing. Current literature is split between a serotonin 5-HT2A receptor (5-HT2AR)-dependent or -independent signaling pathway, as researchers are attempting to harness the mechanisms behind the sustained post-acute therapeutically relevant effects. A combination of molecular, behavioral, and genetic techniques in neuropharmacology has begun to show promise for elucidating these mechanisms. As the field progresses, increasing evidence points towards the importance of the subjective experience induced by psychedelic-assisted therapy, but without further cross validation between clinical and preclinical research, the why behind the experience and its translational validity may be lost.
Collapse
Affiliation(s)
- Alaina M Jaster
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
| |
Collapse
|