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1.
Br J Psychiatry ; : 1-3, 2022 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-35172915

RESUMEN

There are many structural problems facing the UK at present, from a weakened National Health Service to deeply ingrained inequality. These challenges extend through society to clinical practice and have an impact on current mental health research, which was in a perilous state even before the coronavirus pandemic hit. In this editorial, a group of psychiatric researchers who currently sit on the Academic Faculty of the Royal College of Psychiatrists and represent the breadth of research in mental health from across the UK discuss the challenges faced in academic mental health research. They reflect on the need for additional investment in the specialty and ask whether this is a turning point for the future of mental health research.

2.
Mol Psychiatry ; 26(6): 2616-2625, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32296127

RESUMEN

A loss of GABA signaling is a prevailing hypothesis for the pathogenesis of schizophrenia. Preclinical studies indicate that blockade of the α5 subtype of the GABA receptor (α5-GABAARs) leads to behavioral phenotypes associated with schizophrenia, and postmortem evidence indicates lower hippocampal α5-GABAARs protein and mRNA levels in schizophrenia. However, it is unclear if α5-GABAARs are altered in vivo or related to symptoms. We investigated α5-GABAARs availability in antipsychotic-free schizophrenia patients and antipsychotic-medicated schizophrenia patients using [11C]Ro15-4513 PET imaging in a cross-sectional, case-control study design. Thirty-one schizophrenia patients (n = 10 antipsychotic free) and twenty-nine matched healthy controls underwent a [11C]Ro15-4513 PET scan and MRI. The α5 subtype GABA-A receptor availability was indexed using [11C]Ro15-4513 PET imaging. Dynamic PET data were analyzed using the two-tissue compartment model with an arterial plasma input function and total volume of distribution (VT) as the outcome measure. Symptom severity was assessed using the PANSS scale. There was significantly lower [11C]Ro15-4513 VT in the hippocampus of antipsychotic-free patients, but not in medicated patients (p = 0.64), relative to healthy controls (p < 0.05; effect size = 1.4). There was also a significant positive correlation between [11C]Ro15-4513 VT and total PANSS score in antipsychotic-free patients (r = 0.72; p = 0.044). The results suggest that antipsychotic-free patients with schizophrenia have lower α5-GABAARs levels in the hippocampus, consistent with the hypothesis that GABA hypofunction underlies the pathophysiology of the disorder.


Asunto(s)
Receptores de GABA-A , Esquizofrenia , Estudios de Casos y Controles , Estudios Transversales , Humanos , Tomografía de Emisión de Positrones , Receptores de GABA-A/genética , Esquizofrenia/diagnóstico por imagen
3.
BMC Psychiatry ; 22(1): 228, 2022 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-35361184

RESUMEN

BACKGROUND: People with substance use disorders may be at a greater risk of contracting COVID-19 infection and developing medical complications. Several institutional and governmental health agencies across the world developed ad hoc guidance for substance use disorder services and care of individuals misusing substances. We aimed to synthesise the best available recommendations on management and care of people with or at risk of substance use disorders during the COVID-19 pandemic from existing guidelines published in UK, USA, Australia, Canada, New Zealand, and Singapore. METHODS: We systematically searched existing guidelines and websites from 28 international institutions and governmental bodies in the context of the COVID-19 pandemic (May 4th 2021). We summarized the extracted data as answers to specific clinical questions. RESULTS: We organised the available recommendations from 19 sources in three sections. First, we focused on general advice and recommendations for people who misuse alcohol or drugs during the COVID-19 pandemic, the design of contingency plans, safeguarding issues for children and families of service users and advice to the public, patients, and carers. Then, we summarised specific guidelines for people who use illicit drugs and related services, such as opioid substitution treatment and needle and syringe programmes. Finally, we provided a synthesis on specific recommendations for services supporting people who misuse alcohol and key topics in the field, such as management of alcohol detoxification and safe transition between supervised and unsupervised consumption. CONCLUSIONS: Available guidance reflected different approaches, ranging from being extremely cautious in providing recommendations other than generic statements to proposing adaptation of previously available guidelines to confront the challenges of the COVID-19 pandemic. After the early phase, guidance focused on reduction of infection transmission and service delivery. Guidance did not provide advice on infection prevention via vaccination programmes and service access strategies tailored to individuals with substance use disorders.


Asunto(s)
Alcoholismo , COVID-19 , Trastornos Relacionados con Sustancias , Alcoholismo/psicología , Alcoholismo/terapia , Niño , Guías como Asunto , Personal de Salud , Humanos , Pandemias , Trastornos Relacionados con Sustancias/psicología
4.
Alcohol Alcohol ; 57(5): 602-608, 2022 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-35292814

RESUMEN

AIMS: To understand service users' views and experiences of alcohol relapse prevention medication, views of a telephone behavioural modification intervention delivered by pharmacists and the use of Contingency Management (CM) to support acamprosate adherence following assisted alcohol withdrawal. METHODS: Four focus groups were conducted within four alcohol treatment and recovery groups across England (UK), with service users with lived experience of alcohol dependence (26 participants). Semi-structured topic guide was used to explore participants' views and experiences of alcohol relapse prevention medication, a telephone behavioural modification medication intervention delivered by pharmacists, and the use of CM to support acamprosate adherence. These were audio-recorded, transcribed verbatim and thematically analysed inductively and deductively. RESULTS: Four themes were identified: concerns about support and availability of alcohol relapse prevention medication; lack of knowledge and understanding about acamprosate treatment; positive perceptions of acamprosate adherence telephone support from pharmacists; and negative perceptions of CM to support acamprosate adherence. There were misunderstandings about acamprosate's mode of action and strong negative beliefs about CM. However, most were positive about pharmacists' new role to support acamprosate adherence. CONCLUSION: This study highlighted challenges service users face to commence alcohol relapse prevention medication. It appears service users could benefit from a pharmacist-led telephone intervention to improve understanding about acamprosate medication, particularly, if delivered in an engaging and motivating way.


Asunto(s)
Alcoholismo , Servicios Comunitarios de Farmacia , Síndrome de Abstinencia a Sustancias , Acamprosato , Alcoholismo/tratamiento farmacológico , Alcoholismo/prevención & control , Actitud del Personal de Salud , Humanos , Cumplimiento de la Medicación , Farmacéuticos , Rol Profesional , Prevención Secundaria
5.
Pharm Stat ; 21(2): 476-495, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34891221

RESUMEN

There is a growing interest in early phase dose-finding clinical trials studying combinations of several treatments. While the majority of dose finding designs for such setting were proposed for oncology trials, the corresponding designs are also essential in other therapeutic areas. Furthermore, there is increased recognition of recommending the patient-specific doses/combinations, rather than a single target one that would be recommended to all patients in later phases regardless of their characteristics. In this paper, we propose a dose-finding design for a dual-agent combination trial motivated by an opiate detoxification trial. The distinguishing feature of the trial is that the (continuous) dose of one compound is defined externally by the clinicians and is individual for every patient. The objective of the trial is to define the dosing function that for each patient would recommend the optimal dosage of the second compound. Via a simulation study, we have found that the proposed design results in high accuracy of individual dose recommendation and is robust to the model misspecification and assumptions on the distribution of externally defined doses.


Asunto(s)
Neoplasias , Alcaloides Opiáceos , Simulación por Computador , Relación Dosis-Respuesta a Droga , Humanos , Dosis Máxima Tolerada , Oncología Médica , Neoplasias/tratamiento farmacológico , Alcaloides Opiáceos/uso terapéutico , Proyectos de Investigación
6.
Br J Psychiatry ; 218(3): 128-130, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33234181

RESUMEN

Women in academic publishing and academic psychiatry face many challenges of gender inequality, including significant pay differentials, poor visibility in senior positions and a male-dominated hierarchical system. We discuss this problem and outline how the BJPsych plans to tackle these issues it in its own publishing.


Asunto(s)
Equidad de Género , Psiquiatría , Femenino , Humanos , Masculino , Edición
7.
Mol Psychiatry ; 25(8): 1749-1758, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-29942043

RESUMEN

Addiction has been proposed as a 'reward deficient' state, which is compensated for with substance use. There is growing evidence of dysregulation in the opioid system, which plays a key role in reward, underpinning addiction. Low levels of endogenous opioids are implicated in vulnerability for developing alcohol dependence (AD) and high mu-opioid receptor (MOR) availability in early abstinence is associated with greater craving. This high MOR availability is proposed to be the target of opioid antagonist medication to prevent relapse. However, changes in endogenous opioid tone in AD are poorly characterised and are important to understand as opioid antagonists do not help everyone with AD. We used [11C]carfentanil, a selective MOR agonist positron emission tomography (PET) radioligand, to investigate endogenous opioid tone in AD for the first time. We recruited 13 abstinent male AD and 15 control participants who underwent two [11C]carfentanil PET scans, one before and one 3 h following a 0.5 mg/kg oral dose of dexamphetamine to measure baseline MOR availability and endogenous opioid release. We found significantly blunted dexamphetamine-induced opioid release in 5 out of 10 regions-of-interest including insula, frontal lobe and putamen in AD compared with controls, but no significantly higher MOR availability AD participants compared with HC in any region. This study is comparable to our previous results of blunted dexamphetamine-induced opioid release in gambling disorder, suggesting that this dysregulation in opioid tone is common to both behavioural and substance addictions.


Asunto(s)
Alcoholismo/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Dextroanfetamina/administración & dosificación , Dextroanfetamina/farmacología , Péptidos Opioides/metabolismo , Administración Oral , Adulto , Fentanilo/administración & dosificación , Fentanilo/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Tomografía de Emisión de Positrones , Receptores Opioides mu/agonistas , Receptores Opioides mu/metabolismo
8.
Nat Rev Neurosci ; 16(5): 305-12, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25873042

RESUMEN

For several decades, addiction has come to be viewed as a disorder of the dopamine neurotransmitter system; however, this view has not led to new treatments. In this Opinion article, we review the origins of the dopamine theory of addiction and discuss the ability of addictive drugs to elicit the release of dopamine in the human striatum. There is robust evidence that stimulants increase striatal dopamine levels and some evidence that alcohol may have such an effect, but little evidence, if any, that cannabis and opiates increase dopamine levels. Moreover, there is good evidence that striatal dopamine receptor availability and dopamine release are diminished in individuals with stimulant or alcohol dependence but not in individuals with opiate, nicotine or cannabis dependence. These observations have implications for understanding reward and treatment responses in various addictions.


Asunto(s)
Conducta Adictiva/metabolismo , Dopamina/metabolismo , Receptores Dopaminérgicos/metabolismo , Recompensa , Animales , Conducta Adictiva/diagnóstico , Conducta Adictiva/psicología , Humanos
9.
Br J Psychiatry ; 216(4): 178-179, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31685040

RESUMEN

There are few topics that divide public opinion as sharply as the use of psychoactive substances and it is easy to see why. Substance use is complex and can be examined from numerous perspectives, including legal, health, economic, cultural and ethical. These varying approaches can lead to a range of different conclusions. Here we explore some of the common approaches adopted towards drug policy and suggest a number of principles, which may inform a psychiatrist's own view.


Asunto(s)
Drogas Ilícitas , Enfermos Mentales , Psiquiatría , Trastornos Relacionados con Sustancias , Humanos , Drogas Ilícitas/legislación & jurisprudencia , Legislación de Medicamentos , Enfermos Mentales/legislación & jurisprudencia , Psiquiatría/normas , Trastornos Relacionados con Sustancias/terapia
10.
Compr Psychiatry ; 96: 152135, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31810026

RESUMEN

BACKGROUND: People with substance use disorder (SUD) are at significantly greater risk of suicide compared with the general population. In recent years the number of suicides resulting from drug poisoning in England and Wales has increased. We sought to identify and evaluate the effect of interventions to prevent suicide or reduce self-harm among people with SUD. METHODS: We conducted a systematic review of randomised controlled trials (RCTs) of interventions for people with SUD that included suicide or self-harm-related primary outcomes. We searched Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, PubMed, Embase and Web of Science from inception until 13th January 2019. Studies were assessed for bias using the Cochrane Risk of Bias 2 tool. A random effects meta-analysis of standardised mean differences (SMD) was conducted. RESULTS: We identified six RCTs from four countries (Australia, Iran, the United States of America and the United Kingdom) comprising 468 participants in total. All but one study investigated psychosocial interventions. On average across studies there was weak evidence of a small positive effect of interventions on suicide or self-harm outcomes (d=-0.20, 95% CI=-0.39-0.00). LIMITATIONS: Studies were heterogeneous in terms of population, intervention, controls and outcome. There were some concerns regarding bias for all trials. All trials were liable to type II error. CONCLUSIONS: Evidence is currently lacking regarding the effectiveness of interventions to prevent suicide and reduce self-harm amongst people with SUD.


Asunto(s)
Conducta Autodestructiva/prevención & control , Trastornos Relacionados con Sustancias/psicología , Prevención del Suicidio , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Conducta Autodestructiva/complicaciones , Conducta Autodestructiva/psicología , Trastornos Relacionados con Sustancias/complicaciones , Suicidio/psicología
11.
Eur J Neurosci ; 50(3): 2311-2321, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30402987

RESUMEN

Identifying key neural substrates in addiction disorders for targeted drug development remains a major challenge for clinical neuroscience. One emerging target is the opioid system, where substance-dependent populations demonstrate prefrontal opioid dysregulation that predicts impulsivity and relapse. This may suggest that disturbances to the prefrontal opioid system could confer a risk for relapse in addiction due to weakened 'top-down' control over impulsive behaviour. Naltrexone is currently licensed for alcohol dependence and is also used clinically for impulse control disorders. Using a go/no-go (GNG) task, we examined the effects of acute naltrexone on the neural correlates of successful motor impulse control in abstinent alcoholics (AUD), abstinent polysubstance-dependent (poly-SUD) individuals and controls during a randomised double blind placebo controlled fMRI study. In the absence of any differences on GNG task performance, the AUD group showed a significantly greater BOLD response compared to the control group in lateral and medial prefrontal regions during both placebo and naltrexone treatments; effects that were positively correlated with alcohol abstinence. There was also a dissociation in the positive modulating effects of naltrexone in the orbitofrontal cortex (OFC) and anterior insula cortex (AIC) of the AUD and poly-SUD groups respectively. Self-reported trait impulsivity in the poly-SUD group also predicted the effect of naltrexone in the AIC. These results suggest that acute naltrexone differentially amplifies neural responses within two distinct regions of a salience network during successful motor impulse control in abstinent AUD and poly-SUD groups, which are predicted by trait impulsivity in the poly-SUD group.


Asunto(s)
Abstinencia de Alcohol , Disuasivos de Alcohol/uso terapéutico , Alcoholismo/diagnóstico por imagen , Conducta Impulsiva/fisiología , Naltrexona/uso terapéutico , Desempeño Psicomotor/fisiología , Adulto , Disuasivos de Alcohol/farmacología , Alcoholismo/tratamiento farmacológico , Método Doble Ciego , Femenino , Humanos , Conducta Impulsiva/efectos de los fármacos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Naltrexona/farmacología , Desempeño Psicomotor/efectos de los fármacos , Trastornos Relacionados con Sustancias/diagnóstico por imagen , Trastornos Relacionados con Sustancias/tratamiento farmacológico , Adulto Joven
12.
Brain ; 141(2): 459-471, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29272357

RESUMEN

Survivors of a traumatic brain injury can deteriorate years later, developing brain atrophy and dementia. Traumatic brain injury triggers chronic microglial activation, but it is unclear whether this is harmful or beneficial. A successful chronic-phase treatment for traumatic brain injury might be to target microglia. In experimental models, the antibiotic minocycline inhibits microglial activation. We investigated the effect of minocycline on microglial activation and neurodegeneration using PET, MRI, and measurement of the axonal protein neurofilament light in plasma. Microglial activation was assessed using 11C-PBR28 PET. The relationships of microglial activation to measures of brain injury, and the effects of minocycline on disease progression, were assessed using structural and diffusion MRI, plasma neurofilament light, and cognitive assessment. Fifteen patients at least 6 months after a moderate-to-severe traumatic brain injury received either minocycline 100 mg orally twice daily or no drug, for 12 weeks. At baseline, 11C-PBR28 binding in patients was increased compared to controls in cerebral white matter and thalamus, and plasma neurofilament light levels were elevated. MRI measures of white matter damage were highest in areas of greater 11C-PBR28 binding. Minocycline reduced 11C-PBR28 binding (mean Δwhite matter binding = -23.30%, 95% confidence interval -40.9 to -5.64%, P = 0.018), but increased plasma neurofilament light levels. Faster rates of brain atrophy were found in patients with higher baseline neurofilament light levels. In this experimental medicine study, minocycline after traumatic brain injury reduced chronic microglial activation while increasing a marker of neurodegeneration. These findings suggest that microglial activation has a reparative effect in the chronic phase of traumatic brain injury.


Asunto(s)
Lesiones Traumáticas del Encéfalo/complicaciones , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Microglía/efectos de los fármacos , Minociclina/uso terapéutico , Enfermedades Neurodegenerativas/etiología , Adulto , Anciano , Lesiones Traumáticas del Encéfalo/diagnóstico por imagen , Trastornos del Conocimiento/diagnóstico por imagen , Trastornos del Conocimiento/etiología , Estudios Transversales , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Microglía/patología , Persona de Mediana Edad , Enfermedades Neurodegenerativas/inducido químicamente , Proteínas de Neurofilamentos/metabolismo , Pruebas Neuropsicológicas , Tomografía de Emisión de Positrones , Pirimidinas/farmacocinética , Estadísticas no Paramétricas , Adulto Joven
13.
Alcohol Alcohol ; 54(3): 196-203, 2019 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-30916313

RESUMEN

AIM: To review current alcohol hangover research in animals and humans and evaluate key evidence for contributing biological factors. METHOD: Narrative review with alcohol hangover defined as the state the day after a single episode of heavy drinking, when the alcohol concentration in the blood approaches zero. RESULTS: Many of the human studies of hangover are not well controlled, with subjects consuming different concentrations of alcohol over variable time periods and evaluation not blinded. Also, studies have measured different symptoms and use varying methods of measurement. Animal studies show variations with respect to the route of administration (intragastric or intraperitoneal), the behavioural tests utilised and discrepancy in the timepoint used for hangover onset. Human studies have the advantage over animal models of being able to assess subjective hangover severity and its correlation with specific behaviours and/or biochemical markers. However, animal models provide valuable insight into the neural mechanisms of hangover. Despite such limitations, several hangover models have identified pathological changes which correlate with the hangover state. We review studies examining the contribution of alcohol's metabolites, neurotransmitter changes with particular reference to glutamate, neuroinflammation and ingested congeners to hangover severity. CONCLUSION: Alcohol metabolites, neurotransmitter alterations, inflammatory factors and mitochondrial dysfunction are the most likely factors in hangover pathology. Future research should aim to investigate the relationship between these factors and their causal role.


Asunto(s)
Intoxicación Alcohólica/metabolismo , Etanol/farmacocinética , Inflamación/metabolismo , Neurotransmisores/metabolismo , Animales , Encéfalo/metabolismo , Etanol/efectos adversos , Humanos , Inflamación/inducido químicamente
14.
Br J Psychiatry ; 213(6): 679-681, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30475195

RESUMEN

Society is undergoing a shift in gender politics. Science and medicine are part of this conversation, not least as women's representation and pay continue to drop as one progresses through more senior academic and clinical levels. Naming and redressing these inequalities needs to be a priority for us all.Declaration of interestNone.


Asunto(s)
Movilidad Laboral , Fuerza Laboral en Salud , Liderazgo , Sexismo , Derechos de la Mujer , Academias e Institutos , Humanos , Reino Unido
15.
Addict Biol ; 23(1): 425-436, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28247526

RESUMEN

Naltrexone, an opioid receptor antagonist, is commonly used as a relapse prevention medication in alcohol and opiate addiction, but its efficacy and the mechanisms underpinning its clinical usefulness are not well characterized. In the current study, we examined the effects of 50-mg naltrexone compared with placebo on neural network changes associated with substance dependence in 21 alcohol and 36 poly-drug-dependent individuals compared with 36 healthy volunteers. Graph theoretic and network-based statistical analysis of resting-state functional magnetic resonance imaging (MRI) data revealed that alcohol-dependent subjects had reduced functional connectivity of a dispersed network compared with both poly-drug-dependent and healthy subjects. Higher local efficiency was observed in both patient groups, indicating clustered and segregated network topology and information processing. Naltrexone normalized heightened local efficiency of the neural network in alcohol-dependent individuals, to the same levels as healthy volunteers. Naltrexone failed to have an effect on the local efficiency in abstinent poly-substance-dependent individuals. Across groups, local efficiency was associated with substance, but no alcohol exposure implicating local efficiency as a potential premorbid risk factor in alcohol use disorders that can be ameliorated by naltrexone. These findings suggest one possible mechanism for the clinical effects of naltrexone, namely, the amelioration of disrupted network topology.


Asunto(s)
Disuasivos de Alcohol/farmacología , Alcoholismo/diagnóstico por imagen , Encéfalo/efectos de los fármacos , Naltrexona/farmacología , Adulto , Alcoholismo/fisiopatología , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Femenino , Neuroimagen Funcional , Voluntarios Sanos , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Vías Nerviosas , Trastornos Relacionados con Sustancias/diagnóstico por imagen , Trastornos Relacionados con Sustancias/fisiopatología , Adulto Joven
17.
Alcohol Alcohol ; 52(2): 151-158, 2017 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-27915236

RESUMEN

AIMS: To investigate the underlying neurobiology between alcohol use, misuse and dependence and cognitive impairment, particularly Alzheimer's disease (AD). METHODS: Review of the literature using searches of Medline, Pubmed, EMBASE, PsycInfo, and meeting abstracts and presentations. RESULTS: The role of alcohol as a risk factor and contributor for cognitive decline associated with AD has received little attention. This is despite the high prevalence of alcohol use, the potential reversibility of a degree of cognitive impairment and the global burden of AD. Until now the focus has largely been on the toxic effects of alcohol, neuronal loss and the role of thiamine. CONCLUSION: We propose alcohol adds to the cognitive burden seen in dementia through additional mechanisms to neurodegenerative processes or may contribute at various mechanistic points in the genesis and sustenance of AD pathology via neuroinflammation. We describe the common underlying neurobiology in alcohol and AD, and examine ways alcohol likely contributes to neuroinflammation directly via stimulation of Toll-like receptors and indirectly from small bowel changes, hepatic changes, withdrawal and traumatic brain injury to the pathogenesis of AD. SHORT SUMMARY: Alcohol use, misuse and dependence cause cognitive impairment. We propose alcohol adds to the cognitive burden seen in dementia through additional mechanisms to neurodegenerative processes or may contribute at various mechanistic points in the genesis and sustenance of AD pathology via neuroinflammation.


Asunto(s)
Consumo de Bebidas Alcohólicas/efectos adversos , Alcoholismo/complicaciones , Alcoholismo/patología , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/patología , Inflamación/patología , Degeneración Nerviosa/patología , Placa Amiloide/patología , Humanos , Inflamación/complicaciones , Degeneración Nerviosa/complicaciones , Placa Amiloide/complicaciones
19.
Addict Biol ; 22(6): 1576-1589, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27600363

RESUMEN

There is a concerted research effort to investigate brain mechanisms underlying addiction processes that may predicate the development of new compounds for treating addiction. One target is the brain's opioid system, because of its role in the reinforcing effects of substances of abuse. Substance-dependent populations have increased numbers of the mu opioid receptor (MOR) in fronto-striatal regions that predict drug relapse, and demonstrate disturbances in these regions during the processing of non-drug rewards. Naltrexone is currently licensed for alcohol and opiate dependence, and may remediate such disturbances through the blockade of MORs in fronto-striatal reward circuitry. Therefore, we examined the potential acute modulating effects of naltrexone on the anticipation of, and instrumental responding for, non-drug rewards in long-term abstinent alcoholics, alcoholic poly substance-dependent individuals and controls using a monetary incentive delay (MID) task during a randomized double blind placebo controlled functional MRI study. We report that the alcoholic poly substance-dependent group exhibited slower and less accurate instrumental responding compared to alcoholics and controls that was less evident after acute naltrexone treatment. However, naltrexone treatment was unable to remediate disturbances within fronto-striatal regions during reward anticipation and 'missed' rewards in either substance-dependent group. While we have not been able to identify the underlying neural mechanisms for improvement observed with naltrexone in the alcoholic poly-substance dependent group, we can confirm that both substance-dependent groups exhibit substantial neural deficits during an MID task, despite being in long-term abstinence.


Asunto(s)
Alcoholismo/fisiopatología , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/fisiopatología , Descuento por Demora/fisiología , Naltrexona/farmacología , Antagonistas de Narcóticos/farmacología , Adulto , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Motivación , Recompensa , Trastornos Relacionados con Sustancias/fisiopatología , Reino Unido
20.
Addict Biol ; 22(6): 1601-1609, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27739164

RESUMEN

As a behavioural addiction, gambling disorder (GD) provides an opportunity to characterize addictive processes without the potentially confounding effects of chronic excessive drug and alcohol exposure. Impulsivity is an established precursor to such addictive behaviours, and GD is associated with greater impulsivity. There is also evidence of GABAergic dysregulation in substance addiction and in impulsivity. This study therefore investigated GABAA receptor availability in 15 individuals with GD and 19 healthy volunteers (HV) using [11 C]Ro15-4513, a relatively selective α5 benzodiazepine receptor PET tracer and its relationship with impulsivity. We found significantly higher [11 C]Ro15-4513 total distribution volume (VT ) in the right hippocampus in the GD group compared with HV. We found higher levels of the 'Negative Urgency' construct of impulsivity in GD, and these were positively associated with higher [11 C]Ro15-4513 VT in the amygdala in the GD group; no such significant correlations were evident in the HV group. These results contrast with reduced binding of GABAergic PET ligands described previously in alcohol and opiate addiction and add to growing evidence for distinctions in the neuropharmacology between substance and behavioural addictions. These results provide the first characterization of GABAA receptors in GD with [11 C]Ro15-4513 PET and show greater α5 receptor availability and positive correlations with trait impulsivity. This GABAergic dysregulation is potential target for treatment.


Asunto(s)
Conducta Adictiva/metabolismo , Conducta Adictiva/fisiopatología , Encéfalo/fisiopatología , Juego de Azar/metabolismo , Juego de Azar/fisiopatología , Conducta Impulsiva/fisiología , Receptores de GABA-A/metabolismo , Adulto , Azidas , Benzodiazepinas , Encéfalo/diagnóstico por imagen , Radioisótopos de Carbono , Humanos , Masculino , Tomografía de Emisión de Positrones/métodos
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