Combined effects of age and BMI are related to altered cortical thickness in adolescence and adulthood

Overweight and obesity are associated with functional and structural alterations in the brain, but how these associations change across critical developmental periods remains unknown. Here, we examined the relationship between age, body mass index (BMI) and cortical thickness (CT) in healthy adolescents (n = 70; 14–19 y) and adults (n = 75; 25–45 y). We also examined the relationship between adiposity, impulsivity, measured by delay discounting (DD), and CT of the inferior frontal gyrus (IFG), a region key to impulse control. A significant age-by-BMI interaction was observed in both adolescents and adults; however, the direction of this relationship differed between age groups. In adolescents, increased age-adjusted BMI Z-score attenuated age-related CT reductions globally and in frontal, temporal and occipital regions. In adults, increased BMI augmented age-related CT reductions, both globally and in bilateral parietal cortex. Although DD was unrelated to adiposity in both groups, increased DD and adiposity were both associated with reduced IFG thickness in adolescents and adults. Our findings suggest that the known age effects on CT in adolescence and adulthood are moderated by adiposity. The association between weight, cortical development and its functional implications would suggest that future studies of adolescent and adult brain development take adiposity into account.     

Ordalie,recherche de sensations et impulsivité. Analyse critique des définitions

BackgroundIn the fields of psychology and psychiatry, the use of the terms impulsivity, sensation-seeking and ordalie to refer to risk-taking behaviors can sometimes be confusing.ObjectiveThe objective of this study was to establish a clinical definition of the concepts of ordalie, sensation-seeking and impulsivity, in order to analyze the similarities and differences between these concepts.MethodsWe prioritized literature review articles with or without meta-analysis from the Medline database and supplemented with the Google-Scholar database. The articles were included in this review if their objectives were in line with ours. The research was conducted in November 2018.ResultsTwenty-seven articles were selected. There are similarities in the clinical definitions of these concepts with measurable heterogeneous constructions, and an exacerbation in adolescence for engagement in harmful behaviors, but there are also nuances that highlight their differences.ConclusionWe were able to describe areas of divergence and convergence between these three concepts but not to establish a quantitative diagram of the areas of divergence and convergence. It would seem that the coexistence of sensation-seeking and impulsivity in the same individual could explain that individual's involvement in ordalique behaviors. Further studies approaching this hypothesis would seem useful in terms of preventing risk-taking behaviors such as addictive behaviors.     

Les conduites suicidaires dans le trouble bipolaire de type 1

ObjectivesBipolar disorder is one of the most common and severe psychiatric conditions. It is frequently complicated by suicidal behaviors, and patients with BD are among those at higher risk of suicide. The aims of our study were to evaluate the predictive factors of suicidal behaviors in patients with BD type 1, through the assessment of their socio-demographic, clinical and evolutionary characteristics as well as to study the implications of the childhood traumas and impulsivity as predictive factors for suicidal behaviors in these patients with bipolar disorder.MethodsOne hundred patients with bipolar disorder type 1were recruited in order to conduct a cross-sectional, analytical and comparative study. The recruitment involved a first group made up of 40 patients suffering from type 1 bipolar disorder with a history of suicidal acts. This group was compared with a second group made up of 60 patients with no history of attempted suicide. We used a pre-established collection sheet for collecting socio-demographic, clinical and therapeutic data. We also used the Childhood Trauma Questionnaire for the assessment of childhood adversities, the Barratt Impulsivity Scale in its eleventh version for the assessment of impulsivity levels and the Global Assessment of Functioning Scale for the evaluation of overall functioning.ResultsThe suicidal behaviors in patients with bipolar disorder were significantly associated with: female gender (P < 0.001), professional instability (P = 0.002), family history of BD (P = 0.02), family history of other psychiatric disorders (P = 0.003), frequency of depressive episodes (P = 0.002), shorter remission (P = 0.025), more subsyndromal symptoms (P = 0.029), sexual abuse dimension (P = 0.009), and a high level of impulsivity (P < 0.001). The predictive factors for suicidal behaviors in multivariate analysis, after adjusting for the confounding variables were: childhood sexual abuse (P = 0.01; adjusted OR 4.5; 95% CI 1.44–14.2), a high level of impulsivity (P = 0.002; adjusted OR 6.6; 95% CI 2–20), a higher rate of depressive episodes (P = 0.003; adjusted OR 5; 95% CI 1.69–14.2) and more subyndromal symptoms (P = 0.007; adjusted OR 5.8; 95% CI 1.63–20).ConclusionsSuicide prevention is an important mental health subject. It would be imperative to include systematic screening for childhood adversities and adequate management of bipolar disorder and impulsivity.     

COMT genotype,gambling activity,and cognition

Neuropsychological studies of adults with problem gambling indicate impairments across multiple cognitive domains. Catechol-O-methyltransferase (COMT) plays a unique role in the regulation of dopamine in the prefrontal cortex, and has been implicated in the cognitive dysfunction evident in problem gambling. This study examined adults with varying levels of gambling behavior to determine whether COMT genotype was associated with differences in gambling symptoms and cognitive functioning. 260 non-treatment-seeking adults aged 18–29 years with varying degrees of gambling behavior provided saliva samples for genotyping COMT val158met (rs4680). All subjects underwent clinical evaluations and neurocognitive assessment of decision-making, working memory, and impulsivity. The Val/Val COMT genotype was associated with the largest percentage of subjects with gambling disorder (31.8%), a rate significantly different from the Val/Met (13.2%) group (p = 0.001). The Val/Val COMT group was also associated with significantly more gambling disorder diagnostic criteria being met, greater frequency of gambling behavior, and significantly worse cognitive performance on the Cambridge Gamble Task (risk adjustment and delay aversion) and the Spatial Working Memory task (total errors). This study adds to the growing literature on the role of COMT in impulsive behaviors by showing that the Val/Val genotype was associated with specific clinical and cognitive elements among young adults who gamble, in the absence of differences on demographic measures and other cognitive domains. Future work should consider using genotyping to explore whether certain polymorphisms predict subsequent development of impulsive behaviors including gambling disorder, and treatment outcomes.     

Fronto-striatal glutamatergic compounds in compulsive and impulsive syndromes: A review of magnetic resonance spectroscopy studies

Compulsivity and impulsivity are cross-disorder traits observed in autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD) and obsessive compulsive disorder (OCD). Aberrant fronto-striatal glutamatergic signalling is core to the understanding of compulsive and impulsive disorders. In this review, the glutamate (Glu) neurochemistry of fronto-striatal circuits in paediatric and adult ASD, ADHD and OCD, as described in 59 studies, is outlined from the perspective of proton magnetic resonance spectroscopy (¹H MRS). Despite the methodological inconsistencies between studies, two observations stand out that form possible hypotheses for future studies. Firstly, a possible increase in Glx (combination of Glu, glutamine and GABA) in the striatum across ADHD, OCD and ASD. Secondly, an increased Glx signal in the anterior cingulate cortex in paediatric ASD and ADHD but a lower Glx signal in adult ASD and ADHD. This suggests neurodevelopmental changes in fronto-striatal glutamatergic circuits across the lifespan. Future studies should incorporate more homogeneous samples, perform MRS at field strengths of at least 3 Tesla and provide much more precise and standardized information on methods to improve our understanding of fronto-striatal glutamatergic transmission in compulsive and impulsive syndromes.     

Associations of symptoms and subtypes of attention-deficit hyperactivity disorder with visuospatial planning ability in youth

Little is known about which ADHD core symptom or subtype is most associated with visuospatial planning deficit. This issue was investigated in a sample of 408 youths with current DSM-IV diagnosis of ADHD, and 332 youths without lifetime ADHD, aged 8–17 years (mean age 12.02 ± 2.24). All the participants and their mothers were interviewed using the Chinese Kiddie Epidemiologic version of the Schedule for Affective Disorders and Schizophrenia to obtain information about ADHD symptoms and diagnosis and other psychiatric disorders. In addition to clinical assessments, the participants were assessed with the WISC-III and the Stocking of Cambridge task of the Cambridge Neuropsychological Test Automated Battery. Multi-level regression models were used for data analysis. The results showed that univariate analyses revealed that inattention, hyperactivity, and impulsivity were significantly associated with visuospatial planning, and the magnitude of such association was amplified with increased task difficulties. Only inattention independently predicted visuospatial planning in a model that included all three ADHD symptoms. After further controlling for comorbidity, age of assessment, treatment with methylphenidate, and Full-scale IQ, inattention was still independently associated with visuospatial planning indexed by mean moves needed to solve problems. In subtype comparison, participants with combined subtype and those with prominently inattentive subtype, rather than prominently hyperactivity/impulsivity subtype, had poorer visuospatial planning performance. Our findings indicate that inattention is independently associated with impaired visuospatial planning, and dimensional approach retains the important distinction among ADHD symptoms than subtype approach in understanding the neuropsychological functioning of ADHD.     

Olfactory identification deficits and associated response inhibition in obsessive-compulsive disorder: On the scent of the orbitofronto–striatal model

Olfactory identification ability implicates the integrity of the orbitofrontal cortex (OFC). The fronto–striatal circuits including the OFC have been involved in the neuropathology of Obsessive Compulsive Disorder (OCD). However, only a few studies have examined olfactory function in patients with OCD. The Brief Smell Identification Test (B-SIT) and tests from the Cambridge Neuropsychological Automated Battery (CANTAB) were administered to 25 patients with OCD and to 21 healthy matched controls. OCD patients showed a significant impairment in olfactory identification ability as well as widely distributed cognitive deficits in visual memory, executive functions, attention, and response inhibition. The degree of behavioural impairment on motor impulsivity (prolonged response inhibition Stop-Signal Reaction Time) strongly correlated with the B-SIT score. Our study is the first to indicate a shared OFC pathological neural substrate underlying olfactory identification impairment, impulsivity, and OCD. Deficits in visual memory, executive functions and attention further indicate that regions outside of the orbitofronto–striatal loop may be involved in this disorder. Such results may help delineate the clinical complexity of OCD and support more targeted investigations and interventions. In this regard, research on the potential diagnostic utility of olfactory identification deficits in the assessment of OCD would certainly be useful.