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Importance: Tobacco use disorder is associated with dysregulated neurocognitive function in the right inferior frontal gyrus (IFG)-one node in a corticothalamic inhibitory control (IC) network. Objective: To examine associations between IC neural circuitry structure and function and lapse/relapse vulnerability in 2 independent studies of adult smokers. Design, Setting, and Participants: In study 1, treatment-seeking smokers (n = 81) completed an IC task during functional magnetic resonance imaging (fMRI) before making a quit attempt and then were followed up for 10 weeks after their quit date. In study 2, a separate group of smokers (n = 26) performed the same IC task during fMRI, followed by completing a laboratory-based smoking relapse analog task. Study 1 was performed at Duke University Medical Center between 2008 and 2012; study 2 was conducted at the Medical University of South Carolina between 2013 and 2016. Main Outcomes and Measures: Associations between corticothalamic-mediated IC, gray-matter volume, and smoking lapse/relapse. Results: Of the 81 study participants in study 1 (cessation study), 45 were women (56%), with mean (SD) age, 38.4 (10.2) years. In study 1, smoking relapse was associated with less gray-matter volume (F1,74 = 28.32; familywise error P threshold = 0.03), greater IC task-related blood oxygenation level-dependent (BOLD) response in the right IFG (F1,78 = 14.87) and thalamus (F1,78 = 14.97) (P < .05), and weaker corticothalamic task-based functional connectivity (tbFC) (F1,77 = 5.87; P = .02). Of the 26 participants in study 2 (laboratory study), 15 were women (58%), with mean (SD) age, 34.9 (10.3). Similar to study 1, in study 2, greater IC-BOLD response in the right IFG (t23 = -2.49; ß = -0.47; P = .02), and weaker corticothalamic tbFC (t22 = 5.62; ß = 0.79; P < .001) were associated with smoking sooner during the smoking relapse-analog task. In both studies, corticothalamic tbFC mediated the association between IC performance and smoking outcomes. Conclusions and Relevance: In these 2 studies, baseline differences in corticothalamic circuitry function were associated with mediated IC and smoking relapse vulnerability. These findings warrant further examination of interventions for augmenting corticothalamic neurotransmission and enhancing IC during the course of tobacco use disorder treatment.
Assuntos
Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiopatologia , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Rede Nervosa/fisiopatologia , Inibição Neural/fisiologia , Abandono do Hábito de Fumar/psicologia , Fumar/fisiopatologia , Tálamo/diagnóstico por imagem , Tálamo/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiopatologia , Recidiva , Fatores de Risco , Fumar/psicologia , Estatística como Assunto , Transmissão SinápticaRESUMO
BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a risk factor for problematic cannabis use. However, clinical and anecdotal evidence suggest an increasingly popular perception that cannabis is therapeutic for ADHD, including via online resources. Given that the Internet is increasingly utilized as a source of healthcare information and may influence perceptions, we conducted a qualitative analysis of online forum discussions, also referred to as threads, on the effects of cannabis on ADHD to systematically characterize the content patients and caregivers may encounter about ADHD and cannabis. METHODS: A total of 268 separate forum threads were identified. Twenty percent (20%) were randomly selected, which yielded 55 separate forum threads (mean number of individual posts per forum thread = 17.53) scored by three raters (Cohen's kappa = 0.74). A final sample of 401 posts in these forum threads received at least one endorsement on predetermined topics following qualitative coding procedures. RESULTS: Twenty-five (25%) percent of individual posts indicated that cannabis is therapeutic for ADHD, as opposed to 8% that it is harmful, 5% that it is both therapeutic and harmful, and 2% that it has no effect on ADHD. This pattern was generally consistent when the year of each post was considered. The greater endorsement of therapeutic versus harmful effects of cannabis did not generalize to mood, other (non-ADHD) psychiatric conditions, or overall domains of daily life. Additional themes emerged (e.g., cannabis being considered sanctioned by healthcare providers). CONCLUSIONS: Despite that there are no clinical recommendations or systematic research supporting the beneficial effects of cannabis use for ADHD, online discussions indicate that cannabis is considered therapeutic for ADHD-this is the first study to identify such a trend. This type of online information could shape ADHD patient and caregiver perceptions, and influence cannabis use and clinical care.
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Transtorno do Deficit de Atenção com Hiperatividade/terapia , Atitude Frente a Saúde , Cannabis , Maconha Medicinal/uso terapêutico , Educação de Pacientes como Assunto , Percepção , Feminino , Humanos , Conhecimento , Masculino , Maconha Medicinal/efeitos adversos , Fatores de RiscoRESUMO
Posttraumatic stress disorder (PTSD) is associated with increased smoking initiation, maintenance, and relapse. Dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) are neurosteroids that have been associated with mood measures as well as smoking status, and nicotine is associated with increased DHEA and DHEAS levels. Given the difficulties with mood experienced by smokers with PTSD, the purpose of the current study was to evaluate the association between negative affect and anxiety sensitivity with DHEA and DHEAS levels. Ninety-six smokers with and without PTSD provided blood samples for neurosteroid analyses and completed self-report measures of anxiety sensitivity and electronic diary ratings of negative affect. As expected, PTSD smokers reported higher levels of anxiety sensitivity (F(1,94) = 20.67, partial η2 = 0.18, P < 0.0001) and negative affect (F(1,91) = 7.98, partial η2 = 0.08, P = 0.006). After accounting for age and sex, DHEAS was significantly inversely associated with both anxiety sensitivity (F(3,92) = 6.97, partial η2 = 0.07, P = 0.01) and negative affect (F(3,87) = 10.52, partial η2 = 0.11, P = 0.002) across groups. Effect sizes indicated that these effects are moderate to high. No significant interactions of diagnosis and DHEA(S) levels with mood measures were detected. Given that nicotine is known to elevate DHEA(S) levels, these results suggest that DHEAS may serve as a biomarker of the association between mood and nicotine among smokers. Implications for the results include (1) the use of DHEAS measurement across time and across quit attempts and (2) the potential for careful use of DHEA supplementation to facilitate abstinence during smoking cessation.
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Afeto , Ansiedade/sangue , Sulfato de Desidroepiandrosterona/sangue , Desidroepiandrosterona/sangue , Fumar/sangue , Transtornos de Estresse Pós-Traumáticos/sangue , Adulto , Ansiedade/diagnóstico , Ansiedade/psicologia , Biomarcadores/sangue , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Autorrelato , Fumar/psicologia , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/psicologiaRESUMO
Mindfulness meditation involves attending to emotions without cognitive fixation of emotional experience. Over time, this practice is held to promote alterations in trait affectivity and attentional control with resultant effects on well-being and cognition. However, relatively little is known regarding the neural substrates of meditation effects on emotion and cognition. The present study investigated the neurocognitive correlates of emotion interference on cognition in Yoga practitioners and a matched control group (CG) underwent fMRI while performing an event-related affective Stroop task. The task includes image viewing trials and Stroop trials bracketed by neutral or negative emotional distractors. During image viewing trials, Yoga practitioners exhibited less reactivity in right dorsolateral prefrontal cortex (dlPFC) to negative as compared to neutral images; whereas the CG had the opposite pattern. A main effect of valence (negative > neutral) was observed in limbic regions (e.g., amygdala), of which the magnitude was inversely related to dlPFC activation. Exploratory analyses revealed that the magnitude of amygdala activation predicted decreased self-reported positive affect in the CG, but not among Yoga practitioners. During Stroop trials, Yoga practitioners had greater activation in ventrolateral prefrontal cortex (vlPFC) during Stroop trials when negative, compared to neutral, emotional distractor were presented; the CG exhibited the opposite pattern. Taken together, these data suggest that though Yoga practitioners exhibit limbic reactivity to negative emotional stimuli, such reactivity does not have downstream effects on later mood state. This uncoupling of viewing negative emotional images and affect among Yoga practitioners may be occasioned by their selective implementation of frontal executive-dependent strategies to reduce emotional interference during competing cognitive demands and not during emotional processing per se.
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Meditation practice alters intrinsic resting-state functional connectivity (rsFC) in the default mode network (DMN). However, little is known regarding the effects of meditation on other resting-state networks. The aim of current study was to investigate the effects of meditation experience and meditation-state functional connectivity (msFC) on multiple resting-state networks (RSNs). Meditation practitioners (MPs) performed two 5-minute scans, one during rest, one while meditating. A meditation naïve control group (CG) underwent one resting-state scan. Exploratory regression analyses of the relations between years of meditation practice and rsFC and msFC were conducted. During resting-state, MP as compared to CG exhibited greater rsFC within the Dorsal Attention Network (DAN). Among MP, meditation, as compared to rest, strengthened FC between the DAN and DMN and Salience network whereas it decreased FC between the DAN, dorsal medial PFC, and insula. Regression analyses revealed positive correlations between the number of years of meditation experience and msFC between DAN, thalamus, and anterior parietal sulcus, whereas negative correlations between DAN, lateral and superior parietal, and insula. These findings suggest that the practice of meditation strengthens FC within the DAN as well as strengthens the coupling between distributed networks that are involved in attention, self-referential processes, and affective response.
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Hatha yoga techniques, including physical postures (asanas), breathing exercises (pranayama), and meditation, involve the practice of mindfulness. In turn, yoga meditation practices may induce the state of mindfulness, which, when evoked recurrently through repeated practice, may accrue into trait or dispositional mindfulness. Putatively, these changes may be mediated by experience-dependent neuroplastic changes. Though prior studies have identified differences in gray matter volume (GMV) between long-term mindfulness practitioners and controls, no studies to date have reported on whether yoga meditation is associated with GMV differences. The present study investigated GMV differences between yoga meditation practitioners (YMP) and a matched control group (CG). The YMP group exhibited greater GM volume in frontal, limbic, temporal, occipital, and cerebellar regions; whereas the CG had no greater regional greater GMV. In addition, the YMP group reported significantly fewer cognitive failures on the Cognitive Failures Questionnaire (CFQ), the magnitude of which was positively correlated with GMV in numerous regions identified in the primary analysis. Lastly, GMV was positively correlated with the duration of yoga practice. Results from this preliminary study suggest that hatha yoga practice may be associated with the promotion of neuroplastic changes in executive brain systems, which may confer therapeutic benefits that accrue with repeated practice.
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RATIONALE: Exaggerated startle response is a prominent feature of posttraumatic stress disorder (PTSD) although results examining differences in the acoustic startle response (ASR) between those with and without PTSD are mixed. One variable that may affect ASR among persons with PTSD is smoking. Individuals with PTSD are more likely to smoke and have greater difficulty quitting smoking. While smokers with PTSD report that smoking provides significant relief of negative affect and PTSD symptoms, the effects of smoking or nicotine deprivation on startle reactivity among smokers with PTSD are unknown. OBJECTIVES: The purposes of the current study were to (1) examine baseline acoustic startle response (ASR) in smokers with and without PTSD under conditions of overnight abstinence, (2) evaluate the effect of smoking on ASR, and (3) evaluate the contextual effects of trauma versus neutral script presentations. METHODS: ASR was measured among 48 smokers with and without PTSD in the context of a 2 (group: PTSD vs. non-PTSD) x 2 (context: trauma vs. neutral) x 3 (smoking condition: usual brand cigarette vs. denicotinized cigarette vs. no smoking) design. RESULTS: Effects of modest size indicated that (1) PTSD participants demonstrated higher ASR (2) compared to non-PTSD participants, PTSD participants reported greater negative affect following a trauma-related script, and (3) following a trauma-related script and smoking a usual brand cigarette, PTSD participants demonstrated higher ASR. CONCLUSIONS: Although many smokers with PTSD report that smoking reduces PTSD symptoms, results suggest that smoking may actually potentiate or maintain an exaggerated startle response.
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Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Reflexo de Sobressalto/efeitos dos fármacos , Filtro Sensorial/fisiologia , Fumar/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Estimulação Acústica/métodos , Adulto , Monóxido de Carbono/metabolismo , Eletromiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Escalas de Graduação Psiquiátrica , Filtro Sensorial/efeitos dos fármacos , Índice de Gravidade de DoençaRESUMO
Preliminary studies suggest an extinction-based smoking cessation treatment using reduced nicotine content (RNC) cigarettes decreases self-report craving for cigarettes prior to quitting and may be an effective smoking cessation treatment. The aims of this study was to evaluate the effect of an extinction-based smoking cessation treatment on brain responses to smoking cues using blood-oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI). Sixteen (n = 16) dependent smokers were scanned using BOLD fMRI at baseline, following 2-4 weeks of smoking RNC cigarettes while wearing a 21-mg nicotine patch, and 2-4 weeks following quitting smoking. During scanning, participants viewed smoking-related pictures (e.g. lit cigarette) and pictures of people engaged in everyday activities (e.g. using a stapler). Event-related BOLD responses to smoking and control cues were analyzed in regions of interest (ROIs) known to subserve reward, attention, motivation and emotion. The extinction-based treatment simultaneously attenuated responses to smoking cues in amygdala while potentiating responses to control cues. Exploratory analysis indicated that this pattern was also observed in the thalamus of future abstinent but not relapsing smokers. The results of this preliminary study suggest that an extinction-based treatment for smoking cessation alters brain responses to smoking and control cues in amygdala--a region previously associated with drug cue reactivity and extinction.
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Tonsila do Cerebelo/fisiopatologia , Sinais (Psicologia) , Extinção Psicológica/fisiologia , Imageamento por Ressonância Magnética , Oxigênio/sangue , Abandono do Hábito de Fumar , Fumar/fisiopatologia , Administração Cutânea , Adulto , Atenção/fisiologia , Feminino , Humanos , Masculino , Motivação , Nicotina/administração & dosagem , Recidiva , Tálamo/fisiopatologia , Resultado do TratamentoRESUMO
The study investigated the effects of smoking a nicotinized or denicotinized cigarette on craving, affect and posttraumatic stress disorder (PTSD) symptoms while recalling neutral, stressful and traumatic events in smokers with and without PTSD. Smokers completed laboratory sessions during which they were presented with audiotapes of personalized scripts followed by smoking a cigarette. The effect of the script and cigarette conditions on dependent variables was evaluated. There was a main effect of script type across groups for smoking craving, negative affect and PTSD symptoms, with increased symptoms in trauma and stressful conditions. Responses were significantly higher in PTSD smokers. Smoking either cigarette type resulted in decreased craving, negative affect and PTSD symptoms in both groups. A second script presentation following smoking elicited similar responses, suggesting the ameliorative effect of having smoked a cigarette was short-lived. These results support that context and non-pharmacologic effects of smoking are important variables in smoking craving and mood, particularly in smokers with PTSD.