Search

Abstract Background Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by persistent deficits in social interaction and repetitive behaviors (RBs). Therapies specifically targeting RBs have been underexplored despite advances in understanding their neurobiological basis. This study aims to evaluate whether high-definition transcranial direct current stimulation (HD-tDCS) can reduce dysfunctional RBs in autistic children and investigate whether improvements differ between lower-order and higher-order RBs based on the brain regions stimulated. Methods The study entails a multi-session, sham-controlled, site-controlled, double-blind, and between-subjects design. The study will include participants with an ASD diagnosis (aged 8–13 years; IQ ≥ 70), who will undergo the HD-tDCS intervention for 10 sessions. Participants will be randomly assigned to three conditions: (1) Pre-Motor Active Group (active HD-tDCS over pre-SMA cortex); (2) Frontal Active Group (active HD-tDCS over dlPFC); (3) Placebo Control Group. In the active HD-tDCS conditions, the current will be delivered through a 4 × 1 montage; small circular electrodes will be used with the cathode placed centrally with a current intensity of 0.5 mA for a total of 20 min (30 s ramp up/down) per session. Participants during the sham condition will undergo the same procedures as those in the both active conditions actual placement of electrodes, and turning on the HD-tDCS equipment (30 s). The assessment will be completed at baseline (T0), immediately after the end of the intervention (T1) and 3 months after the end of the intervention (T2). The primary outcome measure will be the Total Score of the Repetitive Behavior Scale-Revised. The secondary outcomes measures will comprise ASD symptoms, sensory processing pattern, emotional/behavioral problems, sleep functioning, parental stress, neuropsychological features and High-Density EEG connectivity. We hypothesize that active HD-tDCS will lead to significant reduction in the total score of the primary outcome compared to Sham Group, with site-specific effects on lower-order and higher-order RBs. Discussion HD-tDCS is an easy-to-deliver, time-efficient, neurobiologically-driven intervention that could be performed as add-on to reduce the time of conventional therapy for ASD. Given the inherent limitations of specific interventions for RBs, tDCS represents an important “third” treatment arm to address the burden of interventions for ASD. Trial registration details The trial has been registered at ClinicalTrials.gov (ID: NCT06645587). Registered 17 October 2024.

IntroductionAutistic individuals may show several psychiatric co-occurrences, including Feeding and Eating Disorders (FEDs). Avoidant and Restrictive Food Intake Disorder (ARFID) consists of avoidance or restriction in food intake, leading to significant weight loss, nutritional deficiencies, and marked interference with psychosocial functioning. Both Autism Spectrum Disorder (ASD) and ARFID are characterized by the two main features of cognitive rigidity and sensory sensitivity, which may complicate differential diagnosis. There is a notable lack of information on the manifestation of ASD-ARFID co-occurrence, as well as tailored assessment tools and practice, and therapeutic approaches.Case descriptionThis report provides a detailed description of L., a young girl with a late diagnosis of ASD who also developed unspecific depressive mood disorder and ARFID in co-occurrence. After the diagnosis of ASD, L. underwent multiple evaluations to address emerging psychiatric co-occurrences and symptom exacerbation, and in order to develop the most effective integrated treatment.ConclusionThe case of L. expands the knowledge on the phenotype of Autistic females and exemplifies how delayed diagnosis may exacerbate functioning differences and increase the camouflage phenomenon. Additionally, it underscores the importance of improving tailored evaluation, combined treatment plans, with both cognitive-behavioral therapy and drugs, and monitoring the evolving patterns of Autistic manifestations and associated psychiatric co-occurrences.

Autism Spectrum Disorder (ASD), characterized by socio-communicative abnormalities and restricted, repetitive, and stereotyped behaviors, is part of Neurodevelopmental Disorders (NDDs), a diagnostic category distinctly in accordance with the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, (DSM-5), clearly separated from Schizophrenia Spectrum Disorder (SSD) (schizophrenia, schizophreniform disorder, schizoaffective disorder, schizotypal personality disorder). Over the last four decades, this clear distinction is gradually being replaced, describing ASD and SSD as two heterogeneous conditions but with neurodevelopmental origins and overlaps. Referring to the proposal of a neurodevelopmental continuum model, the current research’s aim is to provide an update of the knowledge to date on the course of clinical symptoms and their overlaps among ASD and SSD. A narrative review of the literature published between January 2010 and June 2023 was conducted. Five studies were included. All studies show a global impairment in both conditions. Two studies show a focus on neurodevelopmental perspective in ASD and SSD. Only one study of these adopts a longitudinal prospective in terms of prognostic markers among ASD and SSD. Three studies underline the overlap between ASD and SSD in terms of negative, disorganized and positive symptomatology. To date, there is a gap in the current scientific literature focused on ASD-SSD course of clinical symptoms and their overlaps from a neurodevelopmental perspective. Future longitudinal studies to identify risk markers and tailored treatments are needed.