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Contains fulltext : 182022.pdf (Publisher’s version ) (Closed access) The putamen has been shown to play a key role in inhibitory control and addiction, and consists of distinct subregions associated with distinct functions. The anterior putamen is thought to be specialized in goal-directed control or response-monitoring in connection with frontal regions, whereas the posterior part is specialized in habitual or automatic responding in connection with sensorimotor regions. The present study is the first to delineate functional networks of the anterior and posterior putamen in a Go-NoGo response inhibition task, and to examine differences between smokers (n = 25) and non-smokers (n = 23) within these networks. Functional connectivity analyses were conducted on fMRI data from a Go-NoGo study, using the generalized form of psychophysiological interaction with anterior and posterior putamen seed regions. In the context of inhibition, the anterior putamen exhibited connectivity with the anterior cingulate cortex (ACC) and precuneus (pFWE

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Contains fulltext : 157565.pdf (Publisher’s version ) (Closed access) 1 p.

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Contains fulltext : 157567.pdf (Publisher’s version ) (Closed access) 1 p.

Contains fulltext : 143439.pdf (Publisher’s version ) (Open Access) BACKGROUND: Children of parents with a substance use disorder (CPSUD) are at increased risk for developing problematic substance use later in life. Endophenotypes may help to clarify the mechanism behind this increased risk. However, substance use and externalizing symptoms may confound the relation between dysregulated physiological stress responding and familial risk for substance use disorders (SUDs). METHODS: We examined whether heart rate (HR) responses differed between CPSUDs and controls. Participants (aged 11-20years) were CPSUDs (N=75) and controls (N=363), semi-matched on the basis of sex, socioeconomic status, and ethnicity. HR was measured continuously during a psychosocial stress procedure. Substance use and externalizing symptoms were self-reported and mother-reported, respectively. RESULTS: A piecewise, mixed-effects model was fit for HR across the stress procedure, with fixed effects for HR reactivity and HR recovery. CPSUDs showed a blunted HR recovery. CPSUDs reported drinking more frequently, were more likely to use tobacco daily, were more likely to report ever use of cannabis and used cannabis more frequently, and exhibited more externalizing symptoms. These variables did not confound the relation between familial risk for SUDs and a blunted HR recovery. CONCLUSION: Our findings suggest dysregulated autonomic nervous system (ANS) responding in CPSUDs and contribute to the accumulating evidence for ANS dysregulation as a potential endophenotype for SUDs. 9 p.

Contains fulltext : 128485.pdf (Publisher’s version ) (Open Access) Background: Several current theories emphasize the role of cognitive control in addiction. The present review evaluates neural deficits in the domains of inhibitory control and error processing in individuals with substance dependence and in those showing excessive addiction-like behaviours. The combined evaluation of event-related potential (ERP) and functional magnetic resonance imaging (fMRI) findings in the present review offers unique information on neural deficits in addicted individuals. Methods: We selected 19 ERP and 22 fMRI studies using stop-signal, go/no-go or Flanker paradigms based on a search of PubMed and Embase. Results: The most consistent findings in addicted individuals relative to healthy controls were lower N2, error-related negativity and error positivity amplitudes as well as hypoactivation in the anterior cingulate cortex (ACC), inferior frontal gyrus and dorsolateral prefrontal cortex. These neural deficits, however, were not always associated with impaired task performance. With regard to behavioural addictions, some evidence has been found for similar neural deficits; however, studies are scarce and results are not yet conclusive. Differences among the major classes of substances of abuse were identified and involve stronger neural responses to errors in individuals with alcohol dependence versus weaker neural responses to errors in other substance-dependent populations. Limitations: Task design and analysis techniques vary across studies, thereby reducing comparability among studies and the potential of clinical use of these measures. Conclusion: Current addiction theories were supported by identifying consistent abnormalities in prefrontal brain function in individuals with addiction. An integrative model is proposed, suggesting that neural deficits in the dorsal ACC may constitute a hallmark neurocognitive deficit under lying addictive behaviours, such as loss of control.

Contains fulltext : 103016.pdf (Publisher’s version ) (Closed access) Aims Hypothalamicpituitaryadrenal (HPA) axis activity may prove a viable biomarker for identifying those susceptible to alcohol use disorders. The purpose of this study was to examine the relation of the age at which adolescents begin drinking with diurnal and stress cortisol. Design Adolescents' diurnal cortisol levels on a normal day and cortisol levels during a stress procedure were examined in relation to the age of onset of alcohol use. Setting and participants All adolescents (aged 14-20 years) were part of a general population study in the Netherlands (n = 2286). Measurements Ten assessments of salivary cortisol taken on a normal day (diurnal cortisol), as well as during a social stress procedure (stress cortisol) were used as indicators of HPA axis activity. Findings The age at which the first alcoholic drink was consumed varied as a function of cortisol levels at the onset of as well as during the stress procedure. Those who began drinking at an earlier age showed lower cortisol levels at the onset of the stressful tasks (r(2) = 0.14, P < 0.001) and during the stressful tasks (r(2) = 0.10, P < 0.05), although not after the tasks (cortisol recovery). Effects were strongest for anticipatory pre-task cortisol levels. Differences in diurnal cortisol levels did not explain variance in the age at which adolescents had begun drinking. Conclusions Lessened activity of the hypothalamic-pituitary-adrenal axis at the onset of and during a stress procedure is present in adolescents who begin drinking at an early age. 11 p.