Improving decision-making and cognitive impulse control in bulimia nervosa by rTMS: An ancillary randomized controlled study.

OBJECTIVE: Impaired decision-making and inhibitory control may be involved in the pathophysiology of psychiatric disorders like bulimia nervosa (BN). Their improvement after neuromodulation may underpin clinical improvement. We assessed the effects of rTMS on these cognitive functions in a sample of women with BN. METHODS: Thirty-nine participants (22 in a sham group and 17 in an rTMS group) were assessed before and after 10 high frequency rTMS sessions over the left dorsolateral prefrontal cortex (DLPFC). RESULTS: The between-group analyses revealed no differences in the final neuropsychological performances. The within-group analyses showed that inhibitory control improved in both the go/no-go task (p = .03) and the BIS cognitive impulsivity subscale (p = .01) in the rTMS group only. Switches toward good choices on the Iowa gambling task significantly improved in the rTMS group only (p = .002), and understanding of the task contingencies increased between the two assessments, also in the rTMS group only (p = .03). DISCUSSION: This preliminary evidence suggests that modulation of left DLPFC might improve two putative cognitive biomarkers of BN.

A Lack of Clinical Effect of High-frequency rTMS to Dorsolateral Prefrontal Cortex on Bulimic Symptoms: A Randomised, Double-blind Trial.

Studies suggest that stimulation of the left dorsolateral prefrontal cortex (DLPFC) reduces food craving in bulimic patients, but evidence supporting repetitive transcranial magnetic stimulation (rTMS) as a therapeutic tool is lacking. We investigated the safety and therapeutic efficacy of an adjunct high-frequency rTMS programme targeting the left DLPFC. Forty-seven women with bulimia nervosa were randomised to a real or sham stimulation group. The real group underwent 10 rTMS sessions, each consisting of 20 trains of 5 seconds with 55-second intervals between trains, at a frequency of 10 Hz. The main outcome was the number of binge episodes in the 15 days following the end of stimulation. Overall, no significant improvement in bingeing and purging symptoms was noted after the programme. rTMS was well tolerated. This suggests that 10 sessions of high-frequency rTMS to the left DLPFC provide no greater benefit than placebo. Future studies should consider methodological issues as well as alternative targets. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

Differentiating constitutional thinness from anorexia nervosa in DSM 5 era.

INTRODUCTION: Constitutional thinness (CT) is an underweight state characterized by normal menstruations and no change in feeding behaviour. Thinness is the only resemblance between Anorexia Nervosa (AN) and CT. Removal of amenorrhea from the new DSM 5 definition of AN might result in misdiagnosis between these two populations. The objective of this study was to compare CT, AN and Control subjects in terms of biological, anthropometric, and psychological markers in order to better distinguish AN from CT subjects. MATERIALS AND METHODS: Body composition, nutritional markers, pituitary hormones, bone markers and psychological scores were evaluated in three groups of young women: fifty-six CT, forty restrictive-type AN and fifty-four Control subjects. For every marker, a receiver Operator Characteristics (ROC) curve was calculated to evaluate the accuracy of differentiation between AN and CT groups. RESULTS: For most studied parameters, CT subjects were similar to Controls but dramatically different from AN subjects. DEBQ Restrained Eating subscale score was identified by ROC data analysis as the only psychological parameter tested to successfully differentiate AN from CT. Free-T3 and Leptin were shown to be powerful markers to differentiate AN and CT populations as they were highly specific and sensitive ones. CONCLUSION: The exclusive use of psychological testing criteria is not always sufficient to differentiate AN and CT patients. Minimally, additional testing of Free T3 levels, which is cheap and widely accessible for general practitioners, should be completed to avoid misdiagnosis which could result in the implementation of ineffective treatment plans and social stigmatization for CT women.

Childhood trauma and emotional processing circuits in schizophrenia: A functional connectivity study.

Childhood trauma strongly impacts emotional responses in schizophrenia. We have explored an association between early trauma and the amygdala functional connectivity using generalized psychophysiological interaction during an emotional task. Twenty-one schizophrenia patients and twenty-five controls were included. In schizophrenia patients, higher levels of sexual abuse and physical neglect during childhood were associated with decreased connectivity between the amygdala and the posterior cingulate/precuneus region. Additionally, patients showed decreased coupling between the amygdala and the posterior cingulate/precuneus region compared to controls. These findings suggest that early trauma could impact later connectivity in specific stress-related circuits affecting self-consciousness and social cognition in schizophrenia.

Wide impairment of cerebral serotoninergic activity but inter-individual heterogeneity in bulimia nervosa patients: a pilot [(18)F]MPPF/PET study.

OBJECTIVES: Bulimia nervosa (BN) is associated with abnormalities of serotoninergic system. Functional or ligand specific brain imaging studies revealed abnormalities in non-overlapping regions. [(18)F]MPPF (4-(2-methoxyphenyl)-1-[2-(N-2-pyridinyl)-p-fluorobenzamido]-ethylpiperazine) is a selective 5-HT1A receptor antagonist with a serotonin-like affinity, capable to assess changes of brain serotoninergic activity in BN patients. METHODS: [(18)F]MPPF cerebral binding potential (BPND) was measured by positron emission tomography scan in nine purging-type BN patients and eleven age-matched controls. Voxel-based statistical parametric mapping (SPM) analyses were performed to assess BPND differences between the two groups and between each BN patient and controls group. RESULTS: Mean [(18)F]MPPF BPND was overall increased in BN patients. SPM analysis with revealed symmetrical large clusters of increased [(18)F]MPPF binding in insula, temporo-parietal cortex, prefrontal cortex, in limbic, paralimbic cortex and raphe nuclei. SPM individual analysis indicated significant heterogeneity of [(18)F]MPPF mapping within BN group, including cases with isolated up to widespread increased binding. [(18)F]MPPF BPND did not covariate with depression or eating behaviour-related scores. CONCLUSIONS: Large clusters of increased [(18)F]MPPF binding in severe BN overlap previous results, separately described within fMRI or PET studies. The relationship between the inter-individual [(18)F]MPPF binding heterogeneity and serotoninergic modulators efficacy in these patients remains to be assessed.