Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 75
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-33618016

RESUMO

BACKGROUND: Smoking behavior during the first 24 hours of a quit attempt is a significant predictor of longer term abstinence, yet little is known about the neurobiology of early tobacco abstinence. Specifically, the effects of acute tobacco deprivation and reinstatement on brain function-particularly at the level of large-scale network dynamics and assessed across the entire brain-remain incompletely understood. To address this gap, this study uses a mixed within- and between-subjects design to assess the effects of smoking status (yes/no smoker) and state (deprived versus satiated) on whole-brain patterns of intrinsic connectivity. METHODS: Forty-two tobacco smokers participated in resting state fMRI following overnight abstinence (deprived state) and following smoking reinstatement (satiated state, randomized order across participants). Sixty healthy control non-smokers participated in a single resting state scan using the same acquisition parameters. Functional connectivity data were analyzed using both a canonical network-of-interest (NOI) approach and a whole-brain, data driven approach, intrinsic connectivity distribution (ICD). RESULTS: NOI-based analyses indicated decreased functional connectivity within frontoparietal and salience networks among smokers relative to nonsmokers, as well as effects of smoking state on default mode connectivity. In addition, ICD analyses identified novel between-group differences in subcortical-cerebellar and cortico-cerebellar networks that were largely smoking state dependent. CONCLUSIONS: These data demonstrate the importance of considering smoking state and the utility of using both theory- and data-driven analysis approaches. These data provide much needed insight into the functional neurobiology of early abstinence, which may be used in the development of novel treatments.

2.
Chronic Stress (Thousand Oaks) ; 4: 2470547020966561, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33210057

RESUMO

Background: Natural disasters can affect mental health and result in symptoms of depression, anxiety, and post-traumatic stress disorder (PTSD). Playback Theatre (PT) is a form of improvisation where actors play-back personal stories told by audience members. Whether PT can be therapeutic in post-disaster settings is not known. Method: We used a series of PT performances and studied levels of depression, anxiety, and PTSD symptoms in a sample of 13 people affected by Hurricane Harvey that happened in Houston, TX, August 2017. Brain imaging, specifically resting state functional connectivity of the amygdala was also studied before and after the PT performances. Results: Both anxiety (p = .001, Cohen's d = -1.25) and PTSD (p = .002, Cohen's d = -1.0) symptoms significantly decreased after a series of 4 PT performances from January 2019 - February 2019. Depression reduction was not significant. We performed resting state functional connectivity (RSFC) MRI before and after the series of performances. We used the right and left amygdala as seeds for RSFC analysis and found that the connectivity between the left amygdala and the bilateral supramarginal gyri was increased after PT. The bilateral supramarginal connectivity with the default mode and the saliency networks increased too, which correlated with reduction in anxiety scores. Conclusions: PT may offer a form of intervention for anxiety caused by disasters. An increase in left amygdala/supramarginal gyri connectivity may be the underlying mechanism.

3.
Am J Addict ; 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33232571

RESUMO

BACKGROUND AND OBJECTIVES: Substance use disorder (SUD) includes maladaptive patterns of substance use despite negative consequences. Previous structural neuroimaging studies showed some structural alterations in SUD, but it remains unknown whether these alterations are specifically associated with SUD or common comorbidities. This study attempts to validate the findings of structural differences between SUD, healthy controls (HC), and psychiatric controls (PC). METHODS: We used HC (N = 86) matched for demographics, and PC (N = 86) matched for demographics and psychiatric diagnoses to a group of SUD patients (N = 86). We assessed the group differences of subcortical volumes, cortical volumes, thickness, and surface areas between SUD and HC. We then analyzed the group differences between SUD and PC within regions showing differences between SUD and HC. RESULTS: SUD had smaller left nucleus accumbens, right thalamus, right hippocampus, left caudal anterior cingulate cortex (ACC) volume, and larger right caudal ACC volume, and right caudal ACC, right caudal middle frontal gyrus (MFG), and right posterior cingulate cortex (PCC) surface than HC. Increased right caudal ACC volume and right PCC surface in SUD were the only findings when compared with PC. Several areas showed thickness alterations between SUD and HC, but none survived multiple comparisons vs PC. DISCUSSION AND CONCLUSIONS: Our findings suggest that cingulate structures may be altered in SUD compared with both HC and PC. SCIENTIFIC SIGNIFICANCE: These results are among the first to indicate that some structural alterations may be SUD-specific, and highlight a cautionary note about using HC in psychiatric biomarker research. (Am J Addict 2020;00:00-00).

4.
Artigo em Inglês | MEDLINE | ID: mdl-33249434

RESUMO

BACKGROUND: Ketamine's potent and rapid antidepressant properties have shown great promise to treat severe forms of major depressive disorder (MDD). A recently hypothesized antidepressant mechanism of action of ketamine is the inhibition of N-methyl-D-aspartate receptor-dependent bursting activity of the habenula (Hb), a small brain structure which modulates reward and affective states. METHODS: Resting-state functional magnetic resonance imaging was conducted in 35 patients with MDD at baseline and 24 hours following treatment with intravenous ketamine. A seed-to-voxel functional connectivity (FC) analysis was performed with the Hb as a seed-of-interest. Pre-post changes in FC and the associations between changes in FC of the Hb and depressive symptom severity were examined. RESULTS: A reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) scores from baseline to 24 hours after ketamine infusion was associated with an increase in FC between the right Hb and a cluster in the right frontal pole (t=4.65, P=0.03, FDR-corrected). A reduction in Quick Inventory of Depressive Symptomatology-Self Report (QIDS-SR) score following ketamine was associated with increased FC between the right Hb and clusters in the right occipital pole (t=5.18, p<0.0001, FDR-corrected), right temporal pole (t=4.97, P<0.0001, FDR-corrected), right parahippocampal gyrus (t=5.80, P=0.001, FDR-corrected), and left lateral occipital cortex (t=4.73, P=0.03, FDR-corrected). Given the small size of the Hb, it is possible that peri-habenular regions contributed to the results. CONCLUSIONS: These preliminary results suggest that the Hb might be involved in ketamine's antidepressant action in patients with MDD, although these findings are limited by the lack of a control group.

5.
J Affect Disord ; 274: 1057-1061, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32663932

RESUMO

BACKGROUND: Avoidant personality disorder (AvPD) is a condition typified by social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluation. AvPD has a high comorbidity rate with other personality disorders and other psychological diagnostic categories. There is very little research investigating subcortical volumetry in AvPD. We studied subcortical brain morphometry in AvPD as compared to both healthy controls and comorbidity-matched psychiatric controls (patients in the same clinic matched for age, sex and all psychiatric diagnoses except for AvPD). METHODS: We compared volumetric measures of 9 bilateral subcortical brain regions between AvPD patients, healthy controls, and psychiatric controls (n = 100 each group). The Bonferroni correction was used to control for multiple comparisons across regions (p < 0.0028). RESULTS: Compared to healthy controls, AvPD patients had lower volume of the left accumbens and left thalamus. However, no significant results were found when comparing AvPD patients and psychiatric controls. An exploratory study of cortical regions showed similar results: statistically significant differences between HC and AvPD (left lateral occipital, left and right pericalcarine smaller in AvPD) but no differences between AvPD and PC. LIMITATIONS: MRI and neuroimaging provides correlational information, and no causal claims can be made. CONCLUSIONS: These results suggest there may be no overt subcortical volumetric differences specific to AvPD, and provide strong cautionary advice when comparing patients to healthy controls, a common practice in psychiatry biomarker research.

6.
Hum Brain Mapp ; 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32596977

RESUMO

The ENIGMA group on Generalized Anxiety Disorder (ENIGMA-Anxiety/GAD) is part of a broader effort to investigate anxiety disorders using imaging and genetic data across multiple sites worldwide. The group is actively conducting a mega-analysis of a large number of brain structural scans. In this process, the group was confronted with many methodological challenges related to study planning and implementation, between-country transfer of subject-level data, quality control of a considerable amount of imaging data, and choices related to statistical methods and efficient use of resources. This report summarizes the background information and rationale for the various methodological decisions, as well as the approach taken to implement them. The goal is to document the approach and help guide other research groups working with large brain imaging data sets as they develop their own analytic pipelines for mega-analyses.

7.
J Affect Disord ; 273: 318-327, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32421619

RESUMO

BACKGROUND: Emerging literature suggests that the arousal and regulatory systems as measured by sleep-wakefulness, heart rate (HR) and heart rate variability (HRV) may be powerful objective warning signs of suicidality. However, there is no systematic literature review examining the association between objective measurements of these variables with suicide and suicidal behavior. METHODS: A web-based, systematic literature search using PubMed and EMBASE was conducted for articles that measured sleep-wakefulness and HR/HRV quantitatively in association with suicide. Search results were limited to human subjects and articles published in peer-reviewed journals in English. There were no restrictions for age, sex, settings and durations of measurements, types of mental illnesses, or comorbidity. RESULTS: Twenty-three studies were included in the current systematic review. Across the studies, consistent patterns of disturbed sleep-wakefulness such as greater sleep onset latency and lower sleep efficiency were related to suicide. In addition, higher HR and lower variance of R-R intervals was an indicator of risk of suicide. LIMITATIONS: Studies that used different equipment for sleep studies (i.e., polysomnography, electroencephalogram, actigraphy) were combined, and potential differences in their findings due to the different equipment were not considered. CONCLUSIONS: Findings provide initial evidence for consistent patterns of sleep-wakefulness and HR/HRV possibly associated with suicidality; however, more studies are needed in order to identify the precise objective variables (e.g., sleep onset latency, high-frequency HRV), as well as time-varying patterns in these variables, that are related to acute suicide risk.

8.
Addict Behav ; 108: 106457, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32371303

RESUMO

Substance abuse is commonly defined as the persistence of drug use despite negative consequences. Recent preclinical work has shown that higher input from the orbitofrontal cortex (OFC) to the dorsal striatum was associated with compulsive reward-seeking behavior despite negative effects. It remains unknown whether drug use is associated with the connectivity between the OFC and dorsal striatum in humans. We studied the resting state functional connectivity (RSFC) between the OFC, dorsal striatum, and habenula (and the whole brain in a separate analysis) in psychiatric inpatients with high (PU, problem users) and low (LU, low users) substance use. We matched PU and LU for psychiatric comorbidities. We found that PU showed higher RSFC between the left OFC and the left dorsal striatum than LU. RSFC between the habenula and both OFC and dorsal striatum was also higher in PU, which suggests the habenula may be a part of the same circuit. Finally, higher RSFC between the OFC and insula was also observed in PU. Our data shows that OFC, habenula, dorsal striatum, and insula may play an important role in PU. Furthermore, we postulate that the habenula may link the mesolimbic and cortico-striatal systems, which are altered in PU.

9.
Chronic Stress (Thousand Oaks) ; 4: 2470547020906799, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32440605

RESUMO

Background: Many research papers claim that patients with specific psychiatric disorders (major depressive disorder, posttraumatic stress disorder, borderline personality disorder, alcohol use disorder, and others) have smaller hippocampi, but most of those reports compared patients to healthy controls. We hypothesized that if psychiatrically matched controls (psychiatric control, matched for demographics and psychiatric comorbidities) were used, much of the biomarker literature in psychiatric research would not replicate. We used hippocampus and amygdala volume only as examples, as these are very commonly replicated results in psychiatry biomarker research. We propose that psychiatry biomarker research could benefit from using psychiatric controls, as the use of healthy controls results in data that are not disorder-specific. Method: Hippocampus/amygdala volumes were compared between major depressive disorder, sex-/age-/race-matched healthy control, and psychiatric control (N = 126/group). Similar comparisons were performed for posttraumatic stress disorder (N = 67), borderline personality disorder (N = 111), and alcohol use disorder (N = 136). Results: Major depressive disorder patients had smaller left (p = 8.79 × 10-3) and right (p = 3.13 × 10-3) hippocampal volumes than healthy control. Posttraumatic stress disorder had smaller left (p = 0.018) and right (p = 8.64 × 10-4) hippocampi than healthy control. Borderline personality disorder had smaller right hippocampus (p = 7.90 × 10-3) and amygdala (p = 1.49 × 10-3) than healthy control. Alcohol use disorder had smaller right hippocampus (p = 0.034) and amygdala (p = .024) than healthy control. No differences were found between any of the four diagnostic groups and psychiatric control. Conclusion: When psychiatric controls were used, there was no difference in hippocampal or amygdalar volume between any of the diagnoses studied and controls. This strategy (keeping all possible relevant variables matched between experimental groups) has been used to advance science for hundreds of years, and we propose should also be used in biomarker psychiatry research.

10.
J Neurosci Methods ; 339: 108695, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32201351

RESUMO

BACKGROUND: Linking human genetics and brain imaging data is extremely challenging, among other reasons because both fields suffer from multiple comparison problems. NEW METHOD: ProcessGeneLists (PGL) links genetics and human brain imaging by using genes associated with a disease and calculating a normalized mRNA expression average of those genes in each brain region. Brain regions in which those genes are most co-expressed become regions of interest (ROIs) to perform brain imaging in participants with and without the disease, decreasing multiple comparisons. Once a region is identified as "imaging-relevant", the genes most responsible for that ROI being highlighted can be genotyped in the imaged sample. This allows to re-analyze imaging data under the light of likely relevant genetics, to study possible brain imaging/gene variant interactions. RESULTS: As proof-of-concept, we created two lists of genes expressed in the habenula and the striatum, to verified that PGL would highlight those regions. Next, we used a list of genes likely important in alcohol abuse from the literature, which identified several brain regions previously associated with alcohol abuse such as the striatum, habenula, and hippocampus. COMPARISON WITH EXISTING METHODS: To our knowledge there is no current method to obtain brain regions of interest from genetics data. CONCLUSIONS: Genetics typically asks "which genes are associated with a disease?" while human brain imaging typically asks "which brain regions are associated with a disease?" PGL asks "which genes, via modulation within specific brain regions, are found to be associated with a disease?".

11.
Artigo em Inglês | MEDLINE | ID: mdl-32084508

RESUMO

Previous magnetic resonance imaging studies of post-traumatic stress disorder (PTSD) have reported cortical volume alterations in the parahippocampal, anterior cingulate cortex, and temporal pole. It is unclear, however, if these cortical regions are specifically associated with PTSD or associated with common comorbidities. Here, we present the result of cortical volume differences between PTSD and healthy and psychiatric controls. In this study, healthy controls (n = 67) were matched for demographic characteristics (age, sex, race) and psychiatric controls (n = 67) were matched for demographic characteristics plus all other psychiatric diagnoses (past and current) to a group of PTSD patients (N = 67). We assessed group differences of 34 bilateral cortical structure volumes using statistically defined brain regions-of-interest from FreeSurfer between PTSD patients and healthy controls. We found 10 regions to be significantly different between PTSD and healthy controls and analyzed the group differences between PTSD and psychiatric controls within these regions. The right temporal pole volume in PTSD was found to be significantly smaller than both healthy and psychiatry controls. Our finding suggests only right temporal pole volume reduction is specifically associated with PTSD, and also highlights the need for using appropriate controls in psychiatry research.

12.
Bull Menninger Clin ; 84(1): 21-34, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31939683

RESUMO

This study aimed to examine habenular resting state functional connectivity (RSFC) abnormalities in tobacco-smoking veterans. The authors explored RSFC in sated smokers (n = 3D 18), overnight deprived smokers (n = 3D 13), and nonsmoker controls (n = 3D 26). Seed-to-voxel analysis was used to explore RSFC in the habenula. Compared to sated smokers, deprived smokers demonstrated higher RSFC between the right habenula and two clusters of voxels: one in the right fusiform gyrus, and one in the left lingual gyrus. To study nicotine withdrawal, the authors used the Shiffman-Jarvik Withdrawal Questionnaire (SJWQ) score as a regressor and found higher RSFC between the right habenula and the left frontal pole in deprived compared to sated smokers. Right habenula RSFC distinguished between sated and deprived smokers and differentiated between sated and deprived smokers when using SJWQ as a regressor, suggesting a habenular role in tobacco withdrawal.

13.
Eat Weight Disord ; 25(5): 1475-1480, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31376112

RESUMO

PURPOSE: Despite anorexia nervosa having the highest mortality rate of mental illnesses, little is known regarding the brain mechanisms involved. Given that lack of interest for food in anorexic patients is related to alterations in the reward system, we tested the hypothesis that patients with past anorexia nervosa (pAN) have altered resting state functional connectivity (RSFC) between the habenula (a major component of the reward system) and its targets. METHODS: RSFC between the habenula and major targets (locus coeruleus, median and dorsal raphe nuclei, substantia nigra, and ventral tegmental area) was studied in 14 psychiatric inpatients with pAN and 14 psychiatric inpatient controls (PC, never-anorexic patients in same clinic, matched for comorbidities). Next, we tested possible correlations between RSFC and suicidal ideation, depression, and anxiety as determined by self-report questionnaires. RESULTS: Left habenula/locus coeruleus RSFC was lower in pAN patients compared to PC. The left habenula/locus coeruleus RSFC was positively correlated with suicidal ideation (past 2 months) in pAN patients, but not in controls. CONCLUSIONS: pAN patients showed long lasting alterations in habenular connectivity. This may have clinical implications, possibly including future evaluation of the habenula as a therapeutic target and the need to carefully monitor suicidality in pAN patients. NO LEVEL OF EVIDENCE: Basic science.

14.
Eur Arch Psychiatry Clin Neurosci ; 270(5): 633-642, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30923939

RESUMO

Variants in three genes coding for components of the serotonergic system, the tryptophan hydroxylase 1 (TPH1) rs1799913, serotonin transporter (SLC6A4) 5-HTTLPR, and serotonin receptor 2A (HTR2A) rs6311, were evaluated for association with suicidal ideation (SI) and with recovery from SI in a psychiatric inpatient population. Five hundred and eighty-two adult inpatients, including 390 patients who had SI, collected from December 2012 to April 2016 were assessed. SI recovery, calculated as change in SI between the first two-week period after admission and weeks 5 and 6, was appraised for association with the three variants. In this preliminary study, both TPH1 and 5-HTTLPR genotypes were associated with recovery (TPH1: recessive model, increased recovery with AC genotype, P = 0.026; additive model, increased recovery with AC genotype, P = 0.037; 5-HTTLPR: recessive model, increased recovery with AC, P = 0.043). When patients with comorbid alcohol use disorder (AUD) were removed, given that TPH1 has been associated with alcoholism, the associations of those recovered from SI with TPH1 rs1799913 remained significant for the additive (increased recovery with AC, P = 0.045) and recessive (increased recovery with C-carriers, P = 0.008) models, and with 5-HTTLPR using the dominant model (increased recovery with S'S', P = 0.016). In females, an association of SI recovery with TPH1 rs1799913 was found using a recessive model (increased recovery with C-carriers, P = 0.031), with 5-HTTLPR using additive (increased recovery with L'S', P = 0.048) and recessive (increased recovery with S'S', P = 0.042) models. Additionally, an association of SI with TPH1 rs1799913 was found in females using both additive (increased risk in AC, P = 0.033) and recessive (increased risk in C-carriers, P = 0.043) models, and with 5-HTTLPR using a recessive model (increased risk in S'S', P = 0.030). This study provides evidence that variation in the TPH1 and serotonin transporter genes play key roles in moderating recovery from SI during treatment in an inpatient psychiatric clinic.

15.
J Clin Invest ; 129(10): 4290-4304, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31483291

RESUMO

Electronic nicotine delivery systems (ENDS) or e-cigarettes have emerged as a popular recreational tool among adolescents and adults. Although the use of ENDS is often promoted as a safer alternative to conventional cigarettes, few comprehensive studies have assessed the long-term effects of vaporized nicotine and its associated solvents, propylene glycol (PG) and vegetable glycerin (VG). Here, we show that compared with smoke exposure, mice receiving ENDS vapor for 4 months failed to develop pulmonary inflammation or emphysema. However, ENDS exposure, independent of nicotine, altered lung lipid homeostasis in alveolar macrophages and epithelial cells. Comprehensive lipidomic and structural analyses of the lungs revealed aberrant phospholipids in alveolar macrophages and increased surfactant-associated phospholipids in the airway. In addition to ENDS-induced lipid deposition, chronic ENDS vapor exposure downregulated innate immunity against viral pathogens in resident macrophages. Moreover, independent of nicotine, ENDS-exposed mice infected with influenza demonstrated enhanced lung inflammation and tissue damage. Together, our findings reveal that chronic e-cigarette vapor aberrantly alters the physiology of lung epithelial cells and resident immune cells and promotes poor response to infectious challenge. Notably, alterations in lipid homeostasis and immune impairment are independent of nicotine, thereby warranting more extensive investigations of the vehicle solvents used in e-cigarettes.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Imunidade Inata/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Adolescente , Adulto , Animais , Modelos Animais de Doenças , Feminino , Homeostase , Humanos , Lipidômica , Pulmão/patologia , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patologia , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Transmissão , Nicotina/administração & dosagem , Nicotina/efeitos adversos , Fosfolipídeos/metabolismo , Enfisema Pulmonar/etiologia , Enfisema Pulmonar/metabolismo , Enfisema Pulmonar/patologia , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/metabolismo , Mucosa Respiratória/patologia , Fumaça/efeitos adversos , Solventes/administração & dosagem , Solventes/efeitos adversos
16.
Am J Addict ; 28(5): 361-366, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31066987

RESUMO

BACKGROUND AND OBJECTIVES: Recent surveys confirm continued increases in the use of electronic-cigarettes (e-cigarettes) in adolescents and adults. Users often state that e-cigarettes reduce tobacco craving and withdrawal symptoms in addition to their smoking. Data from laboratory studies and clinical trials have confirmed these statements, though there are inconsistencies in the outcomes. In this pilot study, we set out to evaluate the effects of e-cigarettes, as compared to the participants' own cigarettes, on baseline craving and smoking severity. METHODS: Using a within-subjects, placebo-controlled study design, 15 tobacco-dependent, e-cigarette naïve participants sustained abstinence overnight. They completed distinct phases of this protocol during four separate study sessions. Participants were randomized to an e-cigarette device containing one of three doses of nicotine (0, 18, or 36 mg/ml) or their own cigarette. Each study visit was ~3 hours long and separated by at least 7 days. Visits included assessments of craving and smoking severity. RESULTS: The data showed that after 10 puffs in both the Own cigarette and e-cigarette conditions, breath carbon monoxide levels increased significantly in the former but not the latter. Questionnaire of Smoking Urges and Choices to Smoke scores were not statistically different across groups after two distinct bouts of 10 puffs each. Additionally, E-cigarette Perceptions Questionnaire responses were not significantly different according to dose. CONCLUSION AND SCIENTIFIC SIGNIFICANCE: This experiment provides data demonstrating that e-cigarettes did not reduce craving or smoking severity in e-cigarette naïve users. However, since this was a pilot study, the conclusions that can be drawn are limited. (Am J Addict 2019;28:361-366).


Assuntos
Monóxido de Carbono/sangue , Fumar Cigarros , Fissura/efeitos dos fármacos , Sistemas Eletrônicos de Liberação de Nicotina , Nicotina/farmacologia , Vaping , Adulto , Fumar Cigarros/sangue , Fumar Cigarros/prevenção & controle , Fumar Cigarros/psicologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Agonistas Nicotínicos/farmacologia , Projetos Piloto , Abandono do Hábito de Fumar/métodos , Síndrome de Abstinência a Substâncias/prevenção & controle , Inquéritos e Questionários , Vaping/sangue , Vaping/psicologia
17.
Philos Trans R Soc Lond B Biol Sci ; 374(1766): 20180132, 2019 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-30966917

RESUMO

Immediate and long-term mechanisms interact in the regulation of action. We will examine neurobiology and practical clinical consequences of these interactions. Long-term regulation of immediate behavioural control is based on analogous responses to highly rewarding or stressful stimuli: (i) impulsivity is a failure of the balance between activation and inhibition in the immediate regulation of action. (ii) Sensitization is a persistently exaggerated behavioural or physiological response to highly salient stimuli, such as addictive stimuli or inescapable stress. Sensitization can generalize across classes of stimuli. (iii) Impulsivity, possibly related to poor modulation of catecholaminergic and glutamatergic functions, may facilitate development of long-term sensitized responses to stressful or addictive stimuli. In turn, impulsivity is prominent in sensitized behaviour. (iv) While impulsivity and sensitization are general components of behaviour, their interactions are prominent in the course of bipolar disorder, emphasizing roles of substance-use, recurrent course and stressors. (v) Suicide is a complex and severe behaviour that exemplifies the manner in which impulsivity facilitates behavioural sensitization and is, in turn, increased by it, leading to inherently unpredictable behaviour. (vi) Interactions between impulsivity and sensitization can provide targets for complementary preventive and treatment strategies for severe immediate and long-term behavioural disorders. Progress along these lines will be facilitated by predictors of susceptibility to behavioural sensitization. This article is part of the theme issue 'Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications'.


Assuntos
Transtorno Bipolar/psicologia , Comportamento Impulsivo , Inibição Psicológica , Recompensa , Transtornos Relacionados ao Uso de Substâncias/psicologia , Humanos
18.
J Atten Disord ; : 1087054719843177, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31014160

RESUMO

OBJECTIVE: The habenula is a small region in the epithalamus that contributes to the regulation of midbrain dopaminergic circuits implicated in attention-deficit hyperactivity disorder (ADHD). This investigation aims to evaluate the intrinsic functional connectivity (iFC) of the habenula in children with ADHD. METHOD: A total of 112 children (5-9 years; 75 ADHD, 37 healthy comparisons) completed anatomical and resting-state functional magnetic resonance imaging (MRI) scans. Habenula regions of interest (ROIs) were identified individually on normalized T1-weighted anatomical images. Seed-based iFC analyses and group comparisons were conducted for habenula ROIs, as well as thalamic ROIs to test the specificity of habenula findings. RESULTS: Children with ADHD exhibited reduced habenula-putamen iFC compared with healthy comparisons. Group differences in thalamic iFC showed no overlap with habenular findings. CONCLUSION: These preliminary findings suggest that habenula-putamen iFC may be disrupted in children with ADHD. Further work is needed to confirm and elucidate the role of this circuit in ADHD pathophysiology.

19.
J Affect Disord ; 242: 211-219, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30195174

RESUMO

INTRODUCTION: The habenula (Hb) is a small midbrain structure that signals negative events and may play a major role in the etiology of psychiatric disorders including depression. The lateral Hb has three major efferent connections: serotonergic raphe nuclei, noradrenergic locus coeruleus, and dopaminergic ventral tegmental area/substantia nigra compacta. We wanted to test whether Hb connectivity may be important to predict treatment outcomes in depression patients. METHODS: We studied whether habenular connectivity at admission into a psychiatric clinic can predict treatment response. We used an inpatient sample (N = 175) to assess habenular connectivity (diffusion tensor imaging and resting state functional connectivity (RSFC) between the Hb and its targets) close to admission. In addition, we obtained the Patient Health Questionnaire-depression module (PHQ-9) close to admission and at discharge. Inpatients in the study entered the clinic with at least moderately severe depression (score 15 and up). Inpatients considered treatment resistant had scores of 9 or more at discharge. RESULTS: Compared to responders, treatment non-responders had lower fractional anisotropy in the right Hb afferent fibers and lower RSFC between right Hb and median raphe, but higher RSFC between left Hb and locus coeruleus. A logistic regression model was significantly different from chance, and explained 27.7% of the variance in treatment resistance (sensitivity = 75%; specificity = 71.9%). DISCUSSION: The anatomical and functional connectivity of the Hb may be a predictor of treatment success in psychiatric populations. Limitations include the Hb small size and the limited time (5 min) of resting state data obtained.


Assuntos
Transtorno Depressivo Maior/diagnóstico por imagem , Imagem de Tensor de Difusão/estatística & dados numéricos , Habenula/diagnóstico por imagem , Adulto , Antidepressivos/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/fisiopatologia , Neurônios Dopaminérgicos/fisiologia , Feminino , Habenula/fisiopatologia , Humanos , Pacientes Internados/psicologia , Locus Cerúleo/diagnóstico por imagem , Locus Cerúleo/fisiopatologia , Modelos Logísticos , Masculino , Valor Preditivo dos Testes , Núcleos da Rafe/diagnóstico por imagem , Núcleos da Rafe/fisiopatologia , Sensibilidade e Especificidade , Resultado do Tratamento
20.
J Neuropsychiatry Clin Neurosci ; 31(1): 49-56, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30282513

RESUMO

The habenula is a small midbrain structure that is important for brain signaling and learning from negative events. Thus, the habenula is strongly connected to both the reward system and motor regions. Increasing evidence suggests a role for the habenula in the etiology of psychiatric disorders, including mood and substance use disorders. However, no studies to date have investigated habenular resting-state functional connectivity (rsFC) in suicide-related behaviors (SB). The authors enrolled 123 individuals with major depressive disorder (MDD) or bipolar disorder and a history of suicide-related behaviors (SB+), 74 individuals with MDD or bipolar disorder and a history of suicidal ideation but no history of SB (SB-), and 75 healthy control subjects (HC). A seed-based approach was used to identify regions showing different rsFC with the habenula followed by region of interest to region of interest post hoc comparisons. Compared with both the SB- and HC groups, the SB+ group showed higher connectivity between the left habenula and the left parahippocampal gyrus, the right amygdala, and the right precentral and postcentral gyri. Patients with mood disorders displayed higher rsFC between the left habenula and left middle temporal gyrus, the left angular gyrus, and the left posterior cingulate cortex, as well as lower rsFC between the right habenula and the left thalamus, when compared with HCs. These findings suggest that the habenula is involved in the neural circuitry of suicide. The higher habenular rsFC found in the SB+ group may mediate a dysfunction in the mechanism that links the habenula with motor activity and contextual associative processing.


Assuntos
Transtorno Bipolar/fisiopatologia , Conectoma/métodos , Transtorno Depressivo Maior/fisiopatologia , Habenula/fisiopatologia , Ideação Suicida , Tentativa de Suicídio , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Tonsila do Cerebelo/fisiopatologia , Transtorno Bipolar/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiopatologia , Transtorno Depressivo Maior/diagnóstico por imagem , Feminino , Habenula/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética , Masculino , Tálamo/diagnóstico por imagem , Tálamo/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA