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Jerlhag E. Animal studies reveal that the ghrelin pathway regulates alcohol-mediated responses. Front Psychiatry 2023; 14:1050973. [PMID: 36970276 PMCID: PMC10030715 DOI: 10.3389/fpsyt.2023.1050973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 02/21/2023] [Indexed: 03/29/2023] Open
Abstract
Alcohol use disorder (AUD) is often described as repeated phases of binge drinking, compulsive alcohol-taking, craving for alcohol during withdrawal, and drinking with an aim to a reduce the negative consequences. Although multifaceted, alcohol-induced reward is one aspect influencing the former three of these. The neurobiological mechanisms regulating AUD processes are complex and one of these systems is the gut-brain peptide ghrelin. The vast physiological properties of ghrelin are mediated via growth hormone secretagogue receptor (GHSR, ghrelin receptor). Ghrelin is well known for its ability to control feeding, hunger, and metabolism. Moreover, ghrelin signaling appears central for alcohol-mediated responses; findings reviewed herein. In male rodents GHSR antagonism reduces alcohol consumption, prevents relapse drinking, and attenuates the motivation to consume alcohol. On the other hand, ghrelin increases the consumption of alcohol. This ghrelin-alcohol interaction is also verified to some extent in humans with high alcohol consumption. In addition, either pharmacological or genetic suppression of GHSR decreases several alcohol-related effects (behavioral or neurochemical). Indeed, this suppression blocks the alcohol-induced hyperlocomotion and dopamine release in nucleus accumbens as well as ablates the alcohol reward in the conditioned place preference model. Although not fully elucidated, this interaction appears to involve areas central for reward, such as the ventral tegmental area (VTA) and brain nodes targeted by VTA projections. As reviewed briefly, the ghrelin pathway does not only modulate alcohol-mediated effects, it regulates reward-related behaviors induced by addictive drugs. Although personality traits like impulsivity and risk-taking behaviors are common in patients with AUD, the role of the ghrelin pathway thereof is unknown and remains to be studied. In summary, the ghrelin pathway regulates addiction processes like AUD and therefore the possibility that GHSR antagonism reduces alcohol or drug-taking should be explored in randomized clinical trials.
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Kharbanda KK, Farokhnia M, Deschaine SL, Bhargava R, Rodriguez-Flores M, Casey CA, Goldstone AP, Jerlhag E, Leggio L, Rasineni K. Role of the ghrelin system in alcohol use disorder and alcohol-associated liver disease: A narrative review. Alcohol Clin Exp Res 2022; 46:2149-2159. [PMID: 36316764 PMCID: PMC9772086 DOI: 10.1111/acer.14967] [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: 08/19/2022] [Revised: 10/21/2022] [Accepted: 10/28/2022] [Indexed: 11/07/2022]
Abstract
Unhealthy alcohol consumption is a global health problem. Adverse individual, public health, and socioeconomic consequences are attributable to harmful alcohol use. Epidemiological studies have shown that alcohol use disorder (AUD) and alcohol-associated liver disease (ALD) are the top two pathologies among alcohol-related diseases. Consistent with the major role that the liver plays in alcohol metabolism, uncontrolled drinking may cause significant damage to the liver. This damage is initiated by excessive fat accumulation in the liver, which can further progress to advanced liver disease. The only effective therapeutic strategies currently available for ALD are alcohol abstinence or liver transplantation. Any molecule with dual-pronged effects at the central and peripheral organs controlling addictive behaviors and associated metabolic pathways are a potentially important therapeutic target for treating AUD and ALD. Ghrelin, a hormone primarily derived from the stomach, has such properties, and regulates both behavioral and metabolic functions. In this review, we highlight recent advances in understanding the peripheral and central functions of the ghrelin system and its role in AUD and ALD pathogenesis. We first discuss the correlation between blood ghrelin concentrations and alcohol use or abstinence. Next, we discuss the role of ghrelin in alcohol-seeking behaviors and finally its role in the development of fatty liver by metabolic regulations and organ crosstalk. We propose that a better understanding of the ghrelin system could open an innovative avenue for improved treatments for AUD and associated medical consequences, including ALD.
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Affiliation(s)
- Kusum K. Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Mehdi Farokhnia
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse, Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism, Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Sara L. Deschaine
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse, Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism, Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA
| | - Raghav Bhargava
- PsychoNeuroEndocrinology Research Group, Division of Psychiatry, Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Marcela Rodriguez-Flores
- PsychoNeuroEndocrinology Research Group, Division of Psychiatry, Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Carol A. Casey
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Anthony P. Goldstone
- PsychoNeuroEndocrinology Research Group, Division of Psychiatry, Department of Brain Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Lorenzo Leggio
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse, Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism, Division of Intramural Clinical and Biological Research, National Institutes of Health, Baltimore and Bethesda, Maryland, USA
- Medication Development Program, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, Maryland, USA
- Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, Rhode Island, USA
- Division of Addiction Medicine, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Neuroscience, Georgetown University Medical Center, Washington DC, USA
| | - Karuna Rasineni
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Sustkova-Fiserova M, Charalambous C, Khryakova A, Certilina A, Lapka M, Šlamberová R. The Role of Ghrelin/GHS-R1A Signaling in Nonalcohol Drug Addictions. Int J Mol Sci 2022; 23:761. [PMID: 35054944 PMCID: PMC8776007 DOI: 10.3390/ijms23020761] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 01/27/2023] Open
Abstract
Drug addiction causes constant serious health, social, and economic burden within the human society. The current drug dependence pharmacotherapies, particularly relapse prevention, remain limited, unsatisfactory, unreliable for opioids and tobacco, and even symptomatic for stimulants and cannabinoids, thus, new more effective treatment strategies are researched. The antagonism of the growth hormone secretagogue receptor type A (GHS-R1A) has been recently proposed as a novel alcohol addiction treatment strategy, and it has been intensively studied in experimental models of other addictive drugs, such as nicotine, stimulants, opioids and cannabinoids. The role of ghrelin signaling in these drugs effects has also been investigated. The present review aims to provide a comprehensive overview of preclinical and clinical studies focused on ghrelin's/GHS-R1A possible involvement in these nonalcohol addictive drugs reinforcing effects and addiction. Although the investigation is still in its early stage, majority of the existing reviewed experimental results from rodents with the addition of few human studies, that searched correlations between the genetic variations of the ghrelin signaling or the ghrelin blood content with the addictive drugs effects, have indicated the importance of the ghrelin's/GHS-R1As involvement in the nonalcohol abused drugs pro-addictive effects. Further research is necessary to elucidate the exact involved mechanisms and to verify the future potential utilization and safety of the GHS-R1A antagonism use for these drug addiction therapies, particularly for reducing the risk of relapse.
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Affiliation(s)
- Magdalena Sustkova-Fiserova
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Chrysostomos Charalambous
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Anna Khryakova
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Alina Certilina
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Marek Lapka
- Department of Pharmacology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic; (C.C.); (A.K.); (A.C.); (M.L.)
| | - Romana Šlamberová
- Department of Physiology, Third Faculty of Medicine, Charles University, Ke Karlovu 4, 120 00 Prague, Czech Republic;
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Tufvesson-Alm M, Shevchouk OT, Jerlhag E. Insight into the role of the gut-brain axis in alcohol-related responses: Emphasis on GLP-1, amylin, and ghrelin. Front Psychiatry 2022; 13:1092828. [PMID: 36699502 PMCID: PMC9868418 DOI: 10.3389/fpsyt.2022.1092828] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/15/2022] [Indexed: 01/11/2023] Open
Abstract
Alcohol use disorder (AUD) contributes substantially to global morbidity and mortality. Given the heterogenicity of this brain disease, available pharmacological treatments only display efficacy in sub-set of individuals. The need for additional treatment options is thus substantial and is the goal of preclinical studies unraveling neurobiological mechanisms underlying AUD. Although these neurobiological processes are complex and numerous, one system gaining recent attention is the gut-brain axis. Peptides of the gut-brain axis include anorexigenic peptide like glucagon-like peptide-1 (GLP-1) and amylin as well as the orexigenic peptide ghrelin. In animal models, agonists of the GLP-1 or amylin receptor and ghrelin receptor (GHSR) antagonists reduce alcohol drinking, relapse drinking, and alcohol-seeking. Moreover, these three gut-brain peptides modulate alcohol-related responses (behavioral and neurochemical) in rodents, suggesting that the alcohol reduction may involve a suppression of alcohol's rewarding properties. Brain areas participating in the ability of these gut-brain peptides to reduce alcohol-mediated behaviors/neurochemistry involve those important for reward. Human studies support these preclinical studies as polymorphisms of the genes encoding for GLP-1 receptor or the ghrelin pathway are associated with AUD. Moreover, a GLP-1 receptor agonist decreases alcohol drinking in overweight patients with AUD and an inverse GHSR agonist reduces alcohol craving. Although preclinical and clinical studies reveal an interaction between the gut-brain axis and AUD, additional studies should explore this in more detail.
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Affiliation(s)
- Maximilian Tufvesson-Alm
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Olesya T Shevchouk
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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5
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Shevchouk OT, Tufvesson-Alm M, Jerlhag E. An Overview of Appetite-Regulatory Peptides in Addiction Processes; From Bench to Bed Side. Front Neurosci 2021; 15:774050. [PMID: 34955726 PMCID: PMC8695496 DOI: 10.3389/fnins.2021.774050] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/08/2021] [Indexed: 12/17/2022] Open
Abstract
There is a substantial need for new pharmacological treatments of addiction, and appetite-regulatory peptides are implied as possible candidates. Appetite regulation is complex and involves anorexigenic hormones such as glucagon-like peptide-1 (GLP-1) and amylin, and orexigenic peptides like ghrelin and all are well-known for their effects on feeding behaviors. This overview will summarize more recent physiological aspects of these peptides, demonstrating that they modulate various aspects of addiction processes. Findings from preclinical, genetic, and experimental clinical studies exploring the association between appetite-regulatory peptides and the acute or chronic effects of addictive drugs will be introduced. Short or long-acting GLP-1 receptor agonists independently attenuate the acute rewarding properties of addictive drugs or reduce the chronic aspects of drugs. Genetic variation of the GLP-1 system is associated with alcohol use disorder. Also, the amylin pathway modulates the acute and chronic behavioral responses to addictive drugs. Ghrelin has been shown to activate reward-related behaviors. Moreover, ghrelin enhances, whereas pharmacological or genetic suppression of the ghrelin receptor attenuates the responses to various addictive drugs. Genetic studies and experimental clinical studies further support the associations between ghrelin and addiction processes. Further studies should explore the mechanisms modulating the ability of appetite-regulatory peptides to reduce addiction, and the effects of combination therapies or different diets on substance use are warranted. In summary, these studies provide evidence that appetite-regulatory peptides modulate reward and addiction processes, and deserve to be investigated as potential treatment target for addiction.
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Affiliation(s)
- Olesya T Shevchouk
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Maximilian Tufvesson-Alm
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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Cornejo MP, Mustafá ER, Barrile F, Cassano D, De Francesco PN, Raingo J, Perello M. THE INTRIGUING LIGAND-DEPENDENT AND LIGAND-INDEPENDENT ACTIONS OF THE GROWTH HORMONE SECRETAGOGUE RECEPTOR ON REWARD-RELATED BEHAVIORS. Neurosci Biobehav Rev 2020; 120:401-416. [PMID: 33157147 DOI: 10.1016/j.neubiorev.2020.10.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/18/2020] [Accepted: 10/20/2020] [Indexed: 02/07/2023]
Abstract
The growth hormone secretagogue receptor (GHSR) is a G-protein-coupled receptor (GPCR) highly expressed in the brain, and also in some peripheral tissues. GHSR activity is evoked by the stomach-derived peptide hormone ghrelin and abrogated by the intestine-derived liver-expressed antimicrobial peptide 2 (LEAP2). In vitro, GHSR displays ligand-independent actions, including a high constitutive activity and an allosteric modulation of other GPCRs. Beyond its neuroendocrine and metabolic effects, cumulative evidence shows that GHSR regulates the activity of the mesocorticolimbic pathway and modulates complex reward-related behaviors towards different stimuli. Here, we review current evidence indicating that ligand-dependent and ligand-independent actions of GHSR enhance reward-related behaviors towards appetitive stimuli and drugs of abuse. We discuss putative neuronal networks and molecular mechanisms that GHSR would engage to modulate such reward-related behaviors. Finally, we briefly discuss imaging studies showing that ghrelin would also regulate reward processing in humans. Overall, we conclude that GHSR is a key regulator of the mesocorticolimbic pathway that influences its activity and, consequently, modulates reward-related behaviors via ligand-dependent and ligand-independent actions.
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Affiliation(s)
- María P Cornejo
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Emilio R Mustafá
- Laboratory of Electrophysiology of the IMBICE, 1900 La Plata, Buenos Aires, Argentina
| | - Franco Barrile
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Daniela Cassano
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Pablo N De Francesco
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina
| | - Jesica Raingo
- Laboratory of Electrophysiology of the IMBICE, 1900 La Plata, Buenos Aires, Argentina
| | - Mario Perello
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], 1900 La Plata, Buenos Aires, Argentina.
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Neasta J, Darcq E, Jeanblanc J, Carnicella S, Ben Hamida S. GPCR and Alcohol-Related Behaviors in Genetically Modified Mice. Neurotherapeutics 2020; 17:17-42. [PMID: 31919661 PMCID: PMC7007453 DOI: 10.1007/s13311-019-00828-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest class of cell surface signaling receptors and regulate major neurobiological processes. Accordingly, GPCRs represent primary targets for the treatment of brain disorders. Several human genetic polymorphisms affecting GPCRs have been associated to different components of alcohol use disorder (AUD). Moreover, GPCRs have been reported to contribute to several features of alcohol-related behaviors in animal models. Besides traditional pharmacological tools, genetic-based approaches mostly aimed at deleting GPCR genes provided substantial information on how key GPCRs drive alcohol-related behaviors. In this review, we summarize the alcohol phenotypes that ensue from genetic manipulation, in particular gene deletion, of key GPCRs in rodents. We focused on GPCRs that belong to fundamental neuronal systems that have been shown as potential targets for the development of AUD treatment. Data are reviewed with particular emphasis on alcohol reward, seeking, and consumption which are behaviors that capture essential aspects of AUD. Literature survey indicates that in most cases, there is still a gap in defining the intracellular transducers and the functional crosstalk of GPCRs as well as the neuronal populations in which their signaling regulates alcohol actions. Further, the implication of only a few orphan GPCRs has been so far investigated in animal models. Combining advanced pharmacological technologies with more specific genetically modified animals and behavioral preclinical models is likely necessary to deepen our understanding in how GPCR signaling contributes to AUD and for drug discovery.
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Affiliation(s)
- Jérémie Neasta
- Laboratoire de Pharmacologie, Faculté de Pharmacie, University of Montpellier, 34093, Montpellier, France
| | - Emmanuel Darcq
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montreal, Quebec, H4H 1R3, Canada
| | - Jérôme Jeanblanc
- Research Group on Alcohol and Pharmacodependences-INSERM U1247, University of Picardie Jules Verne, 80025, Amiens, France
| | - Sebastien Carnicella
- INSERM U1216, Grenoble Institut des Neurosciences (GIN), University of Grenoble Alpes, 38000, Grenoble, France
| | - Sami Ben Hamida
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 Boulevard LaSalle, Montreal, Quebec, H4H 1R3, Canada.
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Farokhnia M, Faulkner ML, Piacentino D, Lee MR, Leggio L. Ghrelin: From a gut hormone to a potential therapeutic target for alcohol use disorder. Physiol Behav 2019; 204:49-57. [DOI: 10.1016/j.physbeh.2019.02.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 01/24/2019] [Accepted: 02/06/2019] [Indexed: 12/22/2022]
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Geisel O, Hellweg R, Wernecke KD, Wiedemann K, Müller CA. Total and acylated ghrelin plasma levels as potential long-term response markers in alcohol-dependent patients receiving high-dose of the GABA-B receptor agonist baclofen. Psychiatry Res 2019; 272:431-437. [PMID: 30611960 DOI: 10.1016/j.psychres.2018.12.095] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 11/09/2018] [Accepted: 12/18/2018] [Indexed: 01/01/2023]
Abstract
The orexigenic hormone ghrelin is involved in the regulation of food intake and energy balance. Previous findings suggest its involvement in the modulation of mesolimbic reward pathways, thus potentially being relevant in the pathophysiology of substance use disorders such as alcohol dependence. In the present study, we assessed plasma levels of total and acylated ghrelin within the BACLAD trial, where alcohol-dependent patients received individually titrated high-dose baclofen (30-270 mg/d) within a randomized, placebo-controlled design. Plasma levels of total ghrelin and acylated ghrelin were measured at baseline, during treatment with individually titrated high-dose baclofen and after termination of the study medication within a timeframe of up to 20 weeks. Multivariate longitudinal non-parametric analysis revealed that plasma levels of total ghrelin significantly decreased in the group of abstinent patients receiving high-dose baclofen. In addition, plasma levels of total ghrelin correlated negatively with days of abstinence during treatment with high-dose baclofen. Plasma levels of acylated ghrelin increased during the study in the group of relapsed patients under baclofen and placebo treatment. These findings suggest that the long-term response to baclofen treatment in alcohol use disorder (AUD) might be monitored by assessing total and acylated ghrelin plasma levels.
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Affiliation(s)
- Olga Geisel
- Charité - Universitätsmedizin Berlin, Department of Psychiatry, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany.
| | - Rainer Hellweg
- Charité - Universitätsmedizin Berlin, Department of Psychiatry, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | | | - Klaus Wiedemann
- Department of Psychiatry, Universitätsklinikum Hamburg Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Christian A Müller
- Charité - Universitätsmedizin Berlin, Department of Psychiatry, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
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Epigenetic outlier profiles in depression: A genome-wide DNA methylation analysis of monozygotic twins. PLoS One 2018; 13:e0207754. [PMID: 30458022 PMCID: PMC6245788 DOI: 10.1371/journal.pone.0207754] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 11/06/2018] [Indexed: 11/22/2022] Open
Abstract
Recent discoveries highlight the importance of stochastic epigenetic changes, as indexed by epigenetic outlier DNA methylation signatures, as a valuable tool to understand aberrant cell function and subsequent human pathology. There is evidence of such changes in different complex disorders as diverse as cancer, obesity and, to a lesser extent, depression. The current study was aimed at identifying outlying DNA methylation signatures of depressive psychopathology. Here, genome-wide DNA methylation levels were measured (by means of Illumina Infinium HumanMethylation450 Beadchip) in peripheral blood of thirty-four monozygotic twins informative for depressive psychopathology (lifetime DSM-IV diagnoses). This dataset was explored to identify outlying epigenetic signatures of depression, operationalized as extreme hyper- or hypo-methylation in affected co-twins from discordant pairs that is not observed across the rest of the study sample. After adjusting for blood cell count, there were thirteen CpG sites across which depressed co-twins from the discordant pairs exhibited outlying DNA methylation signatures. None of them exhibited a methylation outlier profile in the concordant and healthy pairs, and some of these loci spanned genes previously associated with neuropsychiatric phenotypes, such as GHSR and KCNQ1. This exploratory study provides preliminary proof-of-concept validation that epigenetic outlier profiles derived from genome-wide DNA methylation data may be related to depression risk.
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11
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Jerlhag E. Gut-brain axis and addictive disorders: A review with focus on alcohol and drugs of abuse. Pharmacol Ther 2018; 196:1-14. [PMID: 30439457 DOI: 10.1016/j.pharmthera.2018.11.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Due to the limited efficacy of existing medications for addictive disorders including alcohol use disorder (AUD), the need for additional medications is substantial. Potential new medications for addiction can be identified through investigation of the neurochemical substrates mediating the ability of drugs of abuse such as alcohol to activate the mesolimbic dopamine system. Interestingly, recent studies implicate neuropeptides of the gut-brain axis as modulators of reward and addiction processes. The present review therefore summarizes the current studies investigating the ability of the gut-brain peptides ghrelin, glucagon-like peptide-1 (GLP-1), amylin and neuromedin U (NMU) to modulate alcohol- and drug-related behaviors in rodents and humans. Extensive literature demonstrates that ghrelin, the only known orexigenic neuropeptide to date, enhances reward as well as the intake of alcohol, and other drugs of abuse, while ghrelin receptor antagonism has the opposite effects. On the other hand, the anorexigenic peptides GLP-1, amylin and NMU independently inhibits reward from alcohol and drugs of abuse in rodents. Collectively, these rodent and human studies imply that central ghrelin, GLP-1, amylin and NMU signaling may contribute to addiction processes. Therefore, the need for randomized clinical trials investigating the effects of agents targeting these aforementioned systems on drug/alcohol use is substantial.
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Affiliation(s)
- Elisabet Jerlhag
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
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Wittekind DA, Kratzsch J, Mergl R, Enzenbach C, Witte AV, Villringer A, Kluge M. Alcohol consumption is positively associated with fasting serum ghrelin in non-dependent adults: Results from the population-based LIFE-Adult-Study. Psychoneuroendocrinology 2018; 97:143-148. [PMID: 30029157 DOI: 10.1016/j.psyneuen.2018.07.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/03/2018] [Accepted: 07/13/2018] [Indexed: 02/01/2023]
Abstract
BACKGROUND Animal experiments and studies in alcohol dependent patients indicate that ghrelin signaling in the brain is causally involved in the regulation of alcohol reward and intake. Increasing ghrelin levels enhances alcohol craving and intake, blocking ghrelin receptors abolishes these effects. If ghrelin is also involved in non-dependent alcohol consumption in humans, though, remains unknown. The aim was therefore to investigate the relationship between ghrelin serum levels and alcohol consumption in a large population-based sample. METHODS Total ghrelin was determined after an overnight fast in 1666 subjects participating in a population-based cross-sectional study ('LIFE') including 10,000 adults. 1521 subjects were included in this analysis. Alcohol consumption was assessed using a food frequency questionnaire (FFQ). Multiple linear regression analyses and extreme group comparisons testing for statistical differences of alcohol consumption between the highest and lowest quartile according to ghrelin levels were performed. RESULTS Alcohol consumption was positively associated with serum ghrelin; total sample: β = 0.003, p = 0.002; men: β = 0.005, p = 0.023; women: β = 0.002, p = 0.007, adjusted for age, BMI and smoking status. Mean alcohol consumption in men/women belonging to the highest quartile of serum ghrelin levels (men: 21.5 (21.1) g/day; women: 7.5 (11.4) g/day) was considerably higher than in those belonging to the lowest quartile (men: 16.5 (19.3) g/day p < 0.002; women: 4.59 (10.7) g/day p = 0.0001). CONCLUSION This is the first study showing that alcohol consumption is positively associated with serum ghrelin in a population-based sample. The study provides an initial indication that ghrelin is also involved in the regulation of alcohol consumption in non-dependent subjects.
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Affiliation(s)
| | - Jürgen Kratzsch
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany
| | - Roland Mergl
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | - Cornelia Enzenbach
- Institute for Medical Informatics, Statistics, and Epidemiology (IMISE), University of Leipzig, Leipzig, Germany
| | - A Veronica Witte
- Department of Neurology, Max Planck Institute for Cognitive and Brain Sciences, Leipzig, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Cognitive and Brain Sciences, Leipzig, Germany
| | - Michael Kluge
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
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13
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Suchankova P, Yan J, Schwandt ML, Stangl BL, Jerlhag E, Engel JA, Hodgkinson CA, Ramchandani VA, Leggio L. The Leu72Met Polymorphism of the Prepro-ghrelin Gene is Associated With Alcohol Consumption and Subjective Responses to Alcohol: Preliminary Findings. Alcohol Alcohol 2018; 52:425-430. [PMID: 28481975 DOI: 10.1093/alcalc/agx021] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/29/2017] [Indexed: 11/12/2022] Open
Abstract
Aims The orexigenic peptide ghrelin may enhance the incentive value of food-, drug- and alcohol-related rewards. Consistent with preclinical findings, human studies indicate a role of ghrelin in alcohol use disorders (AUD). In the present study an a priori hypothesis-driven analysis was conducted to investigate whether a Leu72Met missense polymorphism (rs696217) in the prepro-ghrelin gene (GHRL), is associated with AUD, alcohol consumption and subjective responses to alcohol. Method Association analysis was performed using the National Institute on Alcohol Abuse and Alcoholism (NIAAA) clinical sample, comprising AUD individuals and controls (N = 1127). Then, a post-hoc analysis using data from a human laboratory study of intravenous alcohol self-administration (IV-ASA, N = 144) was performed to investigate the association of this SNP with subjective responses following a fixed dose of alcohol (priming phase) and alcohol self-administration (ad libitum phase). Results The case-control study revealed a trend association (N = 1127, OR = 0.665, CI = 0.44-1.01, P = 0.056) between AUD diagnosis and Leu72Met. In AUD subjects, the SNP was associated with significantly lower average drinks per day (n = 567, β = -2.49, 95% CI = -4.34 to -0.64, P = 0.008) and significantly fewer heavy drinking days (n = 567, β = -12.00, 95% CI = -19.10 to -4.89, P < 0.001). The IV-ASA study further revealed that 72Met carriers had greater subjective responses to alcohol (P < 0.05) when compared to Leu72Leu both at priming and during ad lib self-administration. Conclusion Although preliminary, these findings suggest that the Leu72Leu genotype may lead to increased risk of AUD possibly via mechanisms involving a lower response to alcohol resulting in excessive alcohol consumption. Further investigations are warranted. Short Summary We investigated whether a Leu72Met missense polymorphism in the prepro-ghrelin gene, is associated with alcohol use disorder, alcohol consumption and subjective responses to alcohol. Although preliminary, results suggest that the Leu72Leu genotype may lead to increased risk of alcohol use disorder possibly via mechanisms involving a lower response to alcohol.
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Affiliation(s)
- Petra Suchankova
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism (NIAAA) and National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), 10 Center Drive (10CRC/15330), Bethesda, MD 20892, USA.,Department of Pharmacology, The Sahlgrenska Academy at University of Gothenburg, Box 431, 405 30 Gothenburg, Sweden
| | - Jia Yan
- Section on Human Psychopharmacology, NIAAA, NIH, 10 Center Drive (10CRC/15330), Bethesda, MD 20892, USA.,Department of Psychiatry, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, 1101 E Marshall Street, Box 980033, Richmond, VA 23298, USA
| | - Melanie L Schwandt
- Office of the Clinical Director, NIAAA, NIH, 10 Center Drive (10CRC/15330), Bethesda, MD 20892, USA
| | - Bethany L Stangl
- Section on Human Psychopharmacology, NIAAA, NIH, 10 Center Drive (10CRC/15330), Bethesda, MD 20892, USA
| | - Elisabet Jerlhag
- Department of Pharmacology, The Sahlgrenska Academy at University of Gothenburg, Box 431, 405 30 Gothenburg, Sweden
| | - Jörgen A Engel
- Department of Pharmacology, The Sahlgrenska Academy at University of Gothenburg, Box 431, 405 30 Gothenburg, Sweden
| | - Colin A Hodgkinson
- Laboratory of Neurogenetics, NIAAA, NIH, 5625 Fishers Lane, Rockville, MD 20892, USA
| | - Vijay A Ramchandani
- Section on Human Psychopharmacology, NIAAA, NIH, 10 Center Drive (10CRC/15330), Bethesda, MD 20892, USA
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism (NIAAA) and National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), 10 Center Drive (10CRC/15330), Bethesda, MD 20892, USA.,Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, 121 South Main Street, Providence, RI 02912, USA
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14
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Koopmann A, Schuster R, Kiefer F. The impact of the appetite-regulating, orexigenic peptide ghrelin on alcohol use disorders: A systematic review of preclinical and clinical data. Biol Psychol 2018; 131:14-30. [DOI: 10.1016/j.biopsycho.2016.12.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 10/13/2016] [Accepted: 12/15/2016] [Indexed: 12/13/2022]
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15
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Prom-Wormley EC, Ebejer J, Dick DM, Bowers MS. The genetic epidemiology of substance use disorder: A review. Drug Alcohol Depend 2017; 180:241-259. [PMID: 28938182 PMCID: PMC5911369 DOI: 10.1016/j.drugalcdep.2017.06.040] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 06/20/2017] [Accepted: 06/23/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND Substance use disorder (SUD) remains a significant public health issue. A greater understanding of how genes and environment interact to regulate phenotypes comprising SUD will facilitate directed treatments and prevention. METHODS The literature studying the neurobiological correlates of SUD with a focus on the genetic and environmental influences underlying these mechanisms was reviewed. Results from twin/family, human genetic association, gene-environment interaction, epigenetic literature, phenome-wide association studies are summarized for alcohol, nicotine, cannabinoids, cocaine, and opioids. RESULTS There are substantial genetic influences on SUD that are expected to influence multiple neurotransmission pathways, and these influences are particularly important within the dopaminergic system. Genetic influences involved in other aspects of SUD etiology including drug processing and metabolism are also identified. Studies of gene-environment interaction emphasize the importance of environmental context in SUD. Epigenetic studies indicate drug-specific changes in gene expression as well as differences in gene expression related to the use of multiple substances. Further, gene expression is expected to differ by stage of SUD such as substance initiation versus chronic substance use. While a substantial literature has developed for alcohol and nicotine use disorders, there is comparatively less information for other commonly abused substances. CONCLUSIONS A better understanding of genetically-mediated mechanisms involved in the neurobiology of SUD provides increased opportunity to develop behavioral and biologically based treatment and prevention of SUD.
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Affiliation(s)
- Elizabeth C Prom-Wormley
- Dvision of Epidemiology, Department of Family Medicine and Population Health, Virginia Commonwealth University, PO Box 980212, Richmond, VA 23298-0212, USA.
| | - Jane Ebejer
- School of Cognitive Behavioural and Social Sciences, University of New England, Armidale, NSW 2350, Australia
| | - Danielle M Dick
- Department of Psychology, Virginia Commonwealth University, PO Box 842509, Richmond, VA 23284-2509, USA
| | - M Scott Bowers
- Faulk Center for Molecular Therapeutics, Biomedical Engeneering, Northwestern University, Evanston, IL 60201, USA
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16
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Koopmann A, Lippmann K, Schuster R, Reinhard I, Bach P, Weil G, Rietschel M, Witt SH, Wiedemann K, Kiefer F. Drinking water to reduce alcohol craving? A randomized controlled study on the impact of ghrelin in mediating the effects of forced water intake in alcohol addiction. Psychoneuroendocrinology 2017; 85:56-62. [PMID: 28822300 DOI: 10.1016/j.psyneuen.2017.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/17/2017] [Accepted: 08/03/2017] [Indexed: 11/26/2022]
Abstract
BACKGROUND Recent data suggest that ghrelin is involved in the pathophysiology of alcohol use disorders, affecting alcohol self-administration and craving. Gastric ghrelin secretion is reduced by stomach distension. We now tested the hypothesis whether the clinically well-known effects of high-volume water intake on craving reduction in alcoholism is mediated by acute changes in ghrelin secretion. METHODS In this randomized human laboratory study, we included 23 alcohol-dependent male inpatient subjects who underwent alcohol cue exposure. Participants of the intervention group drank 1000ml of mineral water within 10min directly thereafter, compared to the participants of the control group who did not. Craving and plasma concentrations of acetylated ghrelin were measured ten times during the 120min following the alcohol cue exposure session. RESULTS In the intervention group, a significant decrease in acetylated ghrelin in plasma compared to the control group was observed. This decrease was correlated to a reduction in patients' subjective level of craving. In the control group, no decrease of acetylated ghrelin in plasma and no association between alcohol craving and changes in plasma concentrations of acetylated ghrelin were observed. CONCLUSIONS Our results present new evidence that the modulation in the ghrelin system by oral water intake mediates the effects of volume intake with craving reduction in alcohol use disorders. Hence, in addition to pharmacological interventions with ghrelin antagonists, the reduction of physiological ghrelin secretion might be a target for future interventions in the treatment of alcohol craving.
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Affiliation(s)
- Anne Koopmann
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Germany; Feuerlein Center on Translational Addiction Medicine (FCTS), University of Heidelberg, Germany.
| | - Katharina Lippmann
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Germany
| | - Rilana Schuster
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Germany; Feuerlein Center on Translational Addiction Medicine (FCTS), University of Heidelberg, Germany
| | - Iris Reinhard
- Department of Biostatistics, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Germany
| | - Patrick Bach
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Germany; Feuerlein Center on Translational Addiction Medicine (FCTS), University of Heidelberg, Germany
| | - Georg Weil
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Germany
| | - Marcella Rietschel
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Germany
| | - Stephanie H Witt
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Germany
| | - Klaus Wiedemann
- Department of Psychiatry & Psychotherapy, University Medical Center, Hamburg, Martinistr. 52, 20246 Hamburg, Germany
| | - Falk Kiefer
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Germany; Feuerlein Center on Translational Addiction Medicine (FCTS), University of Heidelberg, Germany
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17
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Zallar LJ, Farokhnia M, Tunstall BJ, Vendruscolo LF, Leggio L. The Role of the Ghrelin System in Drug Addiction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2017; 136:89-119. [PMID: 29056157 DOI: 10.1016/bs.irn.2017.08.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the past years, a significant volume of research has implicated the appetitive hormone ghrelin in the mechanisms underlying drug use and addiction. From a neuroscientific standpoint, ghrelin modulates both reward and stress pathways, two key drivers of substance use behaviors. Previous investigations support a connection between the ghrelin system and alcohol, stimulants, and tobacco use in both animals and humans, while the research on opioids and cannabis is scarce. In general, upregulation of the ghrelin system seems to enhance craving for drugs as well as substances use. On the other hand, acute and chronic exposure to drugs of abuse influences the ghrelin system at different levels. This chapter summarizes the literature on the relationship between the ghrelin system and substance-related behaviors. We also review recent work investigating the ghrelin system as a potential pharmacological target for treating substance use disorders and discuss the need for additional research.
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Affiliation(s)
- Lia J Zallar
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, United States; Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | - Mehdi Farokhnia
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, United States
| | - Brendan J Tunstall
- Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | - Leandro F Vendruscolo
- Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, United States; Center for Alcohol and Addiction Studies, Brown University, Providence, RI, United States.
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18
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Ayu AP, Dijkstra B, Golbach M, De Jong C, Schellekens A. Good Psychometric Properties of the Addiction Version of the Revised Illness Perception Questionnaire for Health Care Professionals. PLoS One 2016; 11:e0164262. [PMID: 27824872 PMCID: PMC5100923 DOI: 10.1371/journal.pone.0164262] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 09/22/2016] [Indexed: 12/21/2022] Open
Abstract
Background Addiction, or substance dependence, is nowadays considered a chronic relapsing condition. However, perceptions of addiction vary widely, also among healthcare professionals. Perceptions of addiction are thought to contribute to attitude and stigma towards patients with addiction. However, studies into perceptions of addiction among healthcare professionals are limited and instruments for reliable assessment of their perceptions are lacking. The Illness Perception Questionnaire (IPQ) is widely used to evaluate perceptions of illness. The aim of this study was to evaluate the psychometric properties of the IPQ: factor structure, internal consistency, and discriminant validity, when applied to evaluate healthcare professionals’ perceptions of addiction. Methods Participants were 1072 healthcare professionals in training and master students from the Netherlands and Indonesia, recruited from various addiction-training programs. The revised version of the IPQ was adapted to measure perceptions of addiction (IPQ-A). Maximum likelihood method was used to explore the best-fit IPQ factor structure. Internal consistency was evaluated for the final factors. The final factor structure was used to assess discriminant validity of the IPQ, by comparing illness perceptions of addiction between 1) medical students from the Netherlands and Indonesia, 2) medical students psychology students and educational science students from the Netherlands, and 3) participants with different training levels: medical students versus medical doctors. Results Factor analysis revealed an eight-factor structure for the perception subscale (demoralization, timeline chronic, consequences, personal control, treatment control, illness coherence, timeline cyclical emotional representations) and a four-factor structure for the attribution subscale (psychological attributions, risk factors, smoking/alcohol, overwork). Internal reliability was acceptable to good. The IPQ-A was able to detect differences in perceptions between healthcare professionals from different cultural and educational background and level of training. Conclusions The IPQ-A is a valid and reliable instrument to assess healthcare professionals’ perceptions of addiction.
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Affiliation(s)
- Astri Parawita Ayu
- Department of Psychiatry, School of Medicine, Atma Jaya Catholic University of Indonesia, Jakarta, Indonesia.,Nijmegen Institute for Scientist-Pracititoners in Addiction, Radboud University, Nijmegen, The Netherlands
| | - Boukje Dijkstra
- Nijmegen Institute for Scientist-Pracititoners in Addiction, Radboud University, Nijmegen, The Netherlands
| | | | - Cor De Jong
- Nijmegen Institute for Scientist-Pracititoners in Addiction, Radboud University, Nijmegen, The Netherlands
| | - Arnt Schellekens
- Nijmegen Institute for Scientist-Pracititoners in Addiction, Radboud University, Nijmegen, The Netherlands.,Department of Psychiatry, Radboud University Medical Centre, Nijmegen, the Netherlands
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19
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Suchankova P, Nilsson S, Pahlen B, Santtila P, Sandnabba K, Johansson A, Jern P, Engel JA, Jerlhag E. Genetic variation of the growth hormone secretagogue receptor gene is associated with alcohol use disorders identification test scores and smoking. Addict Biol 2016; 21:481-8. [PMID: 26059200 PMCID: PMC5033010 DOI: 10.1111/adb.12277] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The multifaceted gut‐brain peptide ghrelin and its receptor (GHSR‐1a) are implicated in mechanisms regulating not only the energy balance but also the reward circuitry. In our pre‐clinical models, we have shown that ghrelin increases whereas GHSR‐1a antagonists decrease alcohol consumption and the motivation to consume alcohol in rodents. Moreover, ghrelin signaling is required for the rewarding properties of addictive drugs including alcohol and nicotine in rodents. Given the hereditary component underlying addictive behaviors and disorders, we sought to investigate whether single nucleotide polymorphisms (SNPs) located in the pre‐proghrelin gene (GHRL) and GHSR‐1a gene (GHSR) are associated with alcohol use, measured by the alcohol use disorders identification test (AUDIT) and smoking. Two SNPs located in GHRL, rs4684677 (Gln90Leu) and rs696217 (Leu72Met), and one in GHSR, rs2948694, were genotyped in a subset (n = 4161) of a Finnish population‐based cohort, the Genetics of Sexuality and Aggression project. The effect of these SNPs on AUDIT scores and smoking was investigated using linear and logistic regressions, respectively. We found that the minor allele of the rs2948694 SNP was nominally associated with higher AUDIT scores (P = 0.0204, recessive model) and smoking (P = 0.0002, dominant model). Furthermore, post hoc analyses showed that this risk allele was also associated with increased likelihood of having high level of alcohol problems as determined by AUDIT scores ≥ 16 (P = 0.0043, recessive model). These convergent findings lend further support for the hypothesized involvement of ghrelin signaling in addictive disorders.
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Affiliation(s)
- Petra Suchankova
- Department of Pharmacology Institute of Neuroscience and Physiology The Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Staffan Nilsson
- Department of Mathematical Statistics Institute of Mathematical Sciences Chalmers University of Technology Gothenburg Sweden
| | - Bettina Pahlen
- Department of Psychology and Logopedics Abo Akademi University Turku Finland
| | - Pekka Santtila
- Department of Psychology and Logopedics Abo Akademi University Turku Finland
| | - Kenneth Sandnabba
- Department of Psychology and Logopedics Abo Akademi University Turku Finland
| | - Ada Johansson
- Department of Pharmacology Institute of Neuroscience and Physiology The Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
- Department of Psychology and Logopedics Abo Akademi University Turku Finland
| | - Patrick Jern
- Department of Psychology and Logopedics Abo Akademi University Turku Finland
- Department of Behavioral Sciences and Philosophy University of Turku Turku Finland
| | - Jörgen A. Engel
- Department of Pharmacology Institute of Neuroscience and Physiology The Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Elisabet Jerlhag
- Department of Pharmacology Institute of Neuroscience and Physiology The Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
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20
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Suchankova P, Engel JA, Jerlhag E. Sub-chronic Ghrelin Receptor Blockade Attenuates Alcohol- and Amphetamine-Induced Locomotor Stimulation in Mice. Alcohol Alcohol 2015; 51:121-7. [DOI: 10.1093/alcalc/agv100] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/16/2015] [Indexed: 11/14/2022] Open
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