BackgroundA number of characteristics associated with Autism Spectrum Disorders (ASD) are over-represented among patients with Anorexia Nervosa (AN) as well as among relatives of these patients. Yet the co-occurrence of autistic traits in AN has not been fully explored and no previous study has directly compared self-reported evaluations of cognitive and socio-affective skills in AN and ASD.MethodsWe aimed to determine the degree of overlap between AN and ASD from scores on questionnaires classically used to measure ASD impairments. Fifteen AN participants, 15 ASD participants and two groups of matched controls completed a battery of self-reports measuring: autistic traits (Autism-Spectrum Quotient), empathy (Empathy Quotient-short and Interpersonal Reactivity Index), systemizing (Systemizing Quotient-short) and alexithymia (Bermond-Vorst Alexithymia Questionnaire-B). Univariate comparisons of mean totalled scores were performed on each measure (patients vs. controls, and AN vs. ASD), and a Principal Component Analysis was used to study subject proximities in a reduced-factor space constructed from AQ, BVAQ-B and IRI subscales.ResultsThese analyses revealed similarities in a few cognitive domains (Attention Switching, Perspective Taking and Fantasy, lack of emotional introspection) and in some nonspecific affective dimensions (depression and feelings of distress), but also marked dissimilarities in social skills (the ability to communicate emotions to others, empathizing).ConclusionThe AN and ASD participants reported similar needs for sameness, and similar difficulties understanding their emotions and taking the perspective of another, but contrasting abilities to feel concerned in interpersonal situations. Our mixed findings encourage further exploration of transdiagnostic similarities and associations between these disorders.

It is currently unknown whether the antidepressant effect of repetitive transcranial magnetic stimulation (rTMS) depends on specific characteristics of the stimulated frontal area, such as metabolic changes. We investigated the effect of high-frequency rTMS, administered over the most hypometabolic prefrontal area in depressed patients in a two-site, double-blind, randomized placebo-controlled add-on study. Forty-eight patients with medication-resistant major depression underwent magnetic resonance imaging and [(18)F]-fluorodeoxyglucose positron emission tomography (PET) in order to determine a target area for rTMS. After randomization to PET-guided (n = 16), standard (n = 18), or sham rTMS (n = 14) conditions, the patients received 10 sessions of 10-Hz rTMS (1600 pulses/session) at 90% motor threshold. Change from baseline in Montgomery-Asberg Depression Rating Scale (MADRS) scores did not differ between PET-guided, standard and sham groups at 2-wk end-point. Exploratory comparison of left PET-guided (n = 9), right PET-guided, standard, and sham rTMS revealed significant effects. The highest improvement in MADRS scores was observed with left PET-guided (60 + or - 31%), significantly superior to sham (30 + or - 37%, p = 0.01) and right-guided (31 + or - 33%, p = 0.02) stimulation. Comparison between left PET-guided and standard rTMS (49 + or - 28%) was not significant (p = 0.12). Comparison between stimulation over dorsolateral prefrontal cortex (BA 9-46), stimulation of other areas, and sham rTMS was statistically significant. Stimulation over BA 9-46 region (n = 15) was superior to sham rTMS (p = 0.02). The results do not support the general hypothesis of increased antidepressant effects of high-frequency rTMS with prefrontal hypometabolism-related PET guidance. Nonetheless, whether metabolism and anatomy characteristics of left frontal area underneath the coil might account for an increase or speeding up of rTMS effects needs further investigation.