Uncovering the underlying mechanisms and whole-brain dynamics of deep brain stimulation for Parkinson's disease

Deep brain stimulation (DBS) for Parkinson's disease is a highly effective treatment in controlling otherwise debilitating symptoms. Yet the underlying brain mechanisms are currently not well understood. Whole-brain computational modeling was used to disclose the effects of DBS during resting-state functional Magnetic Resonance Imaging in ten patients with Parkinson's disease. Specifically, we explored the local and global impact that DBS has in creating asynchronous, stable or critical oscillatory conditions using a supercritical bifurcation model. We found that DBS shifts global brain dynamics of patients towards a Healthy regime. This effect was more pronounced in very specific brain areas such as the thalamus, globus pallidus and orbitofrontal regions of the right hemisphere (with the left hemisphere not analyzed given artifacts arising from the electrode lead). Global aspects of integration and synchronization were also rebalanced. Empirically, we found higher communicability and coherence brain measures during DBS-ON compared to DBS-OFF. Finally, using our model as a framework, artificial in silico DBS was applied to find potential alternative target areas for stimulation and whole-brain rebalancing. These results offer important insights into the underlying large-scale effects of DBS as well as in finding novel stimulation targets, which may offer a route to more efficacious treatmentsIn this work, Gustavo Deco is supported by the ERC Advanced Grant: DYSTRUCTURE (n. 295129), by the Spanish Research Project PSI2016-75688-P and by the the European Union's Horizon 2020 research and innovation programme under grant agreement n. 720270 (HBP SGA1). Morten Kringelbach is supported by the ERC Consolidator Grant CAREGIVING (n. 615539) and the Center for Music in the Brain, funded by the Danish National Research Foundation (DNRF117). Victor M Saenger is supported by the Research Personnel Training program PSI2013-42091-P funded by the Spanish Ministry of Economy and Competitiveness.info:eu-repo/semantics/publishedVersio

Season of Birth and Dopamine Receptor Gene Associations with Impulsivity, Sensation Seeking and Reproductive Behaviors

Season of birth (SOB) has been associated with many physiological and psychological traits including novelty seeking and sensation seeking. Similar traits have been associated with genetic polymorphisms in the dopamine system. SOB and dopamine receptor genetic polymorphisms may independently and interactively influence similar behaviors through their common effects on the dopaminergic system.Based on a sample of 195 subjects, we examined whether SOB was associated with impulsivity, sensation seeking and reproductive behaviors. Additionally we examined potential interactions of dopamine receptor genes with SOB for the same set of traits. Phenotypes were evaluated using the Sociosexual Orientation Inventory, the Barratt Impulsivity Scale, the Eysenck Impulsivity Questionnaire, the Sensation Seeking Scale, and the Delay Discounting Task. Subjects were also asked about their age at first sex as well as their desired age at the birth of their first child. The dopamine gene polymorphisms examined were Dopamine Receptor D2 (DRD2) TaqI A and D4 (DRD4) 48 bp VNTR. Primary analyses included factorial genderxSOB ANOVAs or binary logistic regression models for each dependent trait. Secondary analysis extended the factorial models by also including DRD2 and DRD4 genotypes as independent variables. Winter-born males were more sensation seeking than non-winter born males. In factorial models including both genotype and season of birth as variables, two previously unobserved effects were discovered: (1) a SOBxDRD4 interaction effect on venturesomeness and (2) a DRD2xDRD4 interaction effect on sensation seeking.These results are consistent with past findings that SOB is related to sensation seeking. Additionally, these results provide tentative support for the hypothesis that SOB modifies the behavioral expression of dopaminergic genetic polymorphism. These findings suggest that SOB should be included in future studies of risky behaviors and behavioral genetic studies of the dopamine system

Observational studies of depression in primary care: what do we know?

<p>Abstract</p> <p>Background</p> <p>We undertook a systematic review of observational studies of depression in primary care to determine 1) the nature and scope of the published studies 2) the methodological quality of the studies; 3) the identified recovery and risk factors for persistent depression and 3) the treatment and health service use patterns among patients.</p> <p>Methods</p> <p>Searches were conducted in MEDLINE, CINAHL and PsycINFO using combinations of topic and keywords, and Medical Subject Headings in MEDLINE, Headings in CINAHL and descriptors in PsycINFO. Searches were limited to adult populations and articles published in English during 1985–2006.</p> <p>Results</p> <p>40 articles from 17 observational cohort studies were identified, most were undertaken in the US or Europe. Studies varied widely in aims and methods making it difficult to meaningfully compare the results. Methodological limitations were common including: selection bias of patients and physicians; small sample sizes (range 35–108 patients at baseline and 20–59 patients at follow-up); and short follow-up times limiting the extent to which these studies can be used to inform our understanding of recovery and relapse among primary care patients with depression. Risk factors for the persistence of depression identified in this review were: severity and chronicity of the depressive episode, the presence of suicidal thoughts, antidepressant use, poorer self-reported quality of life, lower self-reported social support, experiencing key life events, lower education level and unemployment.</p> <p>Conclusion</p> <p>Despite the growing interest in depression being managed as a chronic illness, this review identified only 17 observational studies of depression in primary care, most of which have included small sample sizes and been relatively short-term. Future research should be large enough to investigate risk factors for chronicity and relapse, and should be conducted over a longer time frame.</p

Excessive substance use in bipolar disorder is associated with impaired functioning rather than clinical characteristics, a descriptive study

<p>Abstract</p> <p>Background</p> <p>There is a strong association between bipolar disorder (BD) and substance use disorder (SUD). The clinical and functional correlates of SUD in BD are still unclear and little is known about the role of excessive substance use that does not meet SUD criteria. Thus, the aims of the current study were to investigate lifetime rates of illicit substance use in BD relative to the normal population and if there are differences in clinical and functional features between BD patients with and without excessive substance use.</p> <p>Methods</p> <p>125 consecutively recruited BD in- and outpatients from the Oslo University Hospitals and 327 persons randomly drawn from the population in Oslo, Norway participated. Clinical and functional variables were assessed. Excessive substance use was defined as DSM-IV SUD and/or excessive use according to predefined criteria.</p> <p>Results</p> <p>The rate of lifetime illicit substance use was significantly higher among patients compared to the reference population (OR = 3.03, CI = 1.9-4.8, p < .001). Patients with excessive substance use (45% of total) had poorer educational level, occupational status, GAF-scores and medication compliance, with a trend towards higher suicidality rates, compared to patients without. There were no significant group differences in current symptom levels or disease course between groups.</p> <p>Conclusion</p> <p>The percentage of patients with BD that had tried illicit substances was significantly higher than in the normal population. BD patients with excessive substance use clearly had impaired functioning, but not a worse course of illness compared to patients without excessive substance use. An assessment of substance use beyond SUD criteria in BD is clinically relevant.</p

Mindfulness-based-relapse prevention (MBRP): Evaluation of the impact of a group of Mindfulness Therapy in alcohol relapse prevention for alcohol use disorders

International audienceFor several years, the learning of mindfulness has developed in a psychological intervention perspective, particularly in the field of addiction. Presently, the management of addictions with substances is centered on two questions: the motivation in the change of behaviour and in a significant change in alcohol consumption. Concerning alcohol dependence, the evolution of behaviour is variable and characterized by forgiveness episodes and relapses. Over many years, a treatment for the abuse of substance associated with techniques based on full consciousness (Kabat-Zinn, 1990; Segal et al., 2002) Mindfulness-based relapse prevention (MBRP) was developed by Marlatt et al. (2011). The prevention of the relapse therapy, based on full consciousness, is a program of eight sessions integrating techniques of "mindfulness" into the techniques of prevention of the relapse. However, not much research has focused on the MBRP, the publication of the manual regarding this intervention is too recent (Bowen S et al., 2011). OBJECTIVE: We are interested in the active mechanisms, which are at stake in the MBRP. Indeed, the meditation acts presents many mechanisms in the addicting disorders. Our non-controlled research was based on a protocol in order to evaluate the alcohol consummation, mindfulness, impulsiveness, automatic thoughts, anxiety and abilities to cope. The first results are interesting: reduction of alcohol consummation, increase of mindfulness, reduction of trigger relapse, increasing cognitive flexibility and high degree of satisfaction among participants. METHODOLOGY: An intervention MBRP was proposed to 26~patients who were assigned to three groups. They were questioned about their alcohol consumption and assessed by a protocol of seven evaluations before and after the group MBRP: Five Facets Mindfulness (FFMQ), Impulsive Behavior Scale (UPPS), Acceptance and Action Questionnaire (AAQ II), State Trait Anxiety Inventory (STAI-A, STAI-B), Questionnaire of the automatic thoughts (QPA), and The Drug-Taking Confidence Questionnaire (DTCQ-8). This study exposes the preliminary results of an intervention for substance use disorders called mindfulness-based relapse prevention (mbrp) administered to five groups of alcohol dependent patients in a psychiatric department and a department of alcohol science in France. RESULTS: The results show maintained abstinence and a moderation leading to abstinence for the still consuming patients. According to our evaluations, we obtained several significant results after the therapy, despite our small cohort: patients accepted their thoughts and feelings better (FFMQ-judgment); the tendency to give in to the impulses decreased (urgency-UPPS), and their tolerance to anxiety increased (STAI-YA-YB). Moreover, this study appears to confirm that the MBRP program allows an improvement of self-efficiency. The study continues in order to confirm these results on a larger sample and to explore the long-term results, so as to propose a new work-tool for patients and caregivers

Intérêt et usage des psychostimulants dans le traitement de la dépression du sujet âgé [Psychostimulants for late life depression]

The use of psychostimulants in the treatment of depressive disorders is receiving renewed interest. Recent publications suggest a particular interest of psychostimulants in the treatment of depression in the elderly. The aim of this article is to review the literature on the role of psychostimulants in the treatment of depression in older adults. The literature review focused on efficacy and tolerability studies of psychostimulants in the treatment of depression for the elderly that were published between 1980 and 2016. The only inclusion criterion applied was an average age of the sample studied greater than or equal to 60 years. Overall, 12 trials were selected: 3 controlled trials and 9 uncontrolled trials. Of the 3 controlled trials, one compared parallel groups and the other two were cross-tests. Among the psychostimulants, methylphenidate was the most studied molecule. The trials demonstrate an efficacy of this molecule in particular as an add-on therapy in old-age depression but for the most part with a level of proof that remains insufficient. The small size of the samples and the methodological limitations of the studies obviate the possibility of extracting definitive conclusions concerning the place of psychostimulants in the treatment of depression in the elderly. Further studies are required in particular in the treatment of resistant depressive episodes

DRD2 C957T and taqIA genotyping reveals gender effects and unique low-risk and high-risk genotypes in alcohol dependence

AIMS: As recent conflicting reports describe a genetic association between both the C- and the T-alleles of the dopamine D2 receptor (DRD2) C957T polymorphism (rs6277) in alcohol-dependent subjects, our aim was to examine this polymorphism and TaqIA (rs1800497) in Australian alcohol-dependent subjects. METHODS: The C957T polymorphism was genotyped in 228 patients with alcohol dependence (72 females and 156 males) and 228 healthy controls. RESULTS: The C-allele and C/C genotype of C957T was associated with alcohol dependence, whereas the TaqIA polymorphism was not. When analysed separately for C957T, males showed an even stronger association with the C-allele and females showed no association. The C957T and TaqIA haplotyping revealed a strong association with alcohol dependence and a double-genotype analysis (combining C957T and TaqIA genotypes) revealed that the relative risk of different genotypes varied by up to 27-fold with the TT/A1A2 having an 8.5-fold lower risk of alcohol dependence than other genotypes. CONCLUSION: Decreased DRD2 binding associated with the C-allele of the DRD2 C957T polymorphism is likely to be important in the underlying pathophysiology of at least some forms of alcohol dependence, and this effect appears to be limited to males only