Sensory over-responsivity and symptoms across the obsessive-compulsive spectrum: a web-based study (Preprint)

Childhood obsessive-compulsive disorder, epigenetics, and heterochrony: An evolutionary and developmental approach

Childhood obsessive-compulsive disorder (OCD) stems from a bunch of restricted and repetitive behaviors, which are part of normal behavioral repertoire up to the age of 7. The persistence of compulsive-like behaviors after that age is often associated with unique comorbidity patterns, which are age-at-onset dependent and reflect different developmental stages. In particular, OCD synchronically co-occurs with a broad constellation of neurodevelopmental disorders, whereas diachronically it is related to an increased risk of major adult psychoses. Moreover, OCD is associated with trait-like sensory phenomena, suggesting a common disrupted sensorimotor grounding.The present study is aimed at exploring the hypothesis that this specific temporal and comorbidity OCD profile may be due to a developmental heterochronic mechanism of delay in attenuation of ontogenetically early behavioral patterns. The developmental shift of highly evolutionarily conserved behavioral phenotypes might be regulated by epigenetic changes induced by different conditions of sensory unbalance. This evolutionary and developmental model allows capturing childhood OCD in light of the ultimate causes of ritual behavior throughout phylogeny, namely its "homeostatic" function over conditions of unpredictability. Moreover, it may have important clinical implications, as OCD symptoms could represent putative biomarkers of early divergent developmental trajectories, with a pathoplastic effect on course and outcome.

Development and validation of the Gastrointestinal Symptom Severity Scale in Spanish children and adolescents

Functional gastrointestinal disorders (FGIDs) are characterized by chronic or recurrent gastrointestinal symptoms (GS) that are not explained by structural or biochemical abnormalities. FGIDs are related to lower quality of life, increased demands on medical resources, and greater somatization and emotional instability. Furthermore, GS appears to be an indicator of dysbiosis in gut-microbiota, affecting the gut-microbiota-brain relationship. To develop and evaluate the psychometric properties of a new instrument called the Gastrointestinal Symptom Severity Scale (GSSS) using a web-based survey in a sample of neurotypical children and adolescents from Spain. Instrument development and validation processes were applied to the GSSS following its administration as part of an online survey. The sample included 1242 neurotypical children and adolescents. The mean age of participants was 13.95 years, with a standard deviation of 1.37 years. Overall, 13.8% suffered infectious diarrhea, 12.6% suffered abdominal pain, 5% suffered dyspepsia and 2.6% suffered gastro-esophageal reflux. A single-factor model produced good fit indices. Furthermore, internal consistency and test-retest reliability outcomes were acceptable. The GSSS was found to have acceptable metric measurement invariance. Significant correlations with other instruments were produced and were of expected direction and magnitude, confirming scale validity for hypothesis testing.     Conclusions: The GSSS shows promising psychometric properties for assessing GS in neurotypical Spanish adolescents and children. What is Known: • To the best of our knowledge, instruments assessing the severity of gastrointestinal symptoms in children and adolescents are still too few. What is New: • The GSSS shows promising psychometric properties for assessing GS in neurotypical adolescents and children. The GSSS may help improve understanding of GS involvement in the gut-brain microbiota axis in children and adolescents.

Psychometric Properties of the Gastrointestinal Symptom Severity Scale in a Sample of Adolescents and Young Adults

Background: Functional gastrointestinal disorders (FGIDs) are a set of chronic or recurrent gastrointestinal symptoms (GS) with great psychobiological complexity. The appearance of FGIDs harms quality of life and drains medical resources. Methods: Psychometric properties of the Gastrointestinal Symptom Severity Scale (GSSS) based on Rome IV criteria were examined in a sample of 1247 individuals with typical development. Observations were randomly divided into two subsets, namely, subsample 1 (n = 624) and subsample 2 (n = 623). Exploratory factor analysis (EFA) was performed with data from subsample 1, whilst confirmatory factor analysis (CFA) was performed with data from subsample 2. Internal consistency of the scale was assessed for the whole dataset according to ordinal alpha, whilst four-week reliability was measured according to the intraclass correlation coefficient (ICC). Measurement invariance as a function of sex was also examined, and discriminant-convergent validity of the GSSS was examined through hypothesis testing. Results: EFA revealed a two-factor structure with a moderate percentage of explained variance (51.3%), whilst CFA exhibited an excellent fit of the data to the model. A one-factor CFA model demonstrated an acceptable but slightly lower fit. Internal consistency was moderate and test-retest reliability was deemed adequate. Metric invariance was demonstrated as a function of sex. Hypothesis testing demonstrated strong convergent-discriminant validity with measures of sensory sensitivity, obsessive-compulsive symptoms, and pain. Conclusions: The GSSS is a tool with acceptable and promising psychometric properties when administered to neurotypical adolescents and young adults. The self-report GSSS may promote better understanding of GS involvement in the gut microbiota-brain axis in the general population.

Obsessive-Compulsive Symptoms in Children Are Related to Sensory Sensitivity and to Seeking Proxies for Internal States

Symptoms of obsessive-compulsive disorder are related to atypical sensory processing, particularly sensory over-responsivity, in both children and adults. In adults, obsessive-compulsive symptoms are also associated with the attenuation of access to the internal state and compensatory reliance on proxies for these states, including fixed rules and rituals. We aimed to examine the associations between sensory over-responsivity, the tendency to seek proxies for internal states, and obsessive-compulsive symptoms in children. Parents of 404 children between 5 and 10 years of age completed online measures of obsessive-compulsive symptoms, seeking proxies for internal states, sensory over-responsivity, and anxiety. Linear regression, dominance analysis, and network analysis were used to explore the unique associations between these variables. The tendency to seek proxies for internal states was more strongly associated with obsessive-compulsive symptoms than with anxiety symptoms and uniquely associated with all major obsessive-compulsive symptom dimensions except obsessing. Both the tendency to seek proxies for internal states and sensory over-responsivity were significantly associated with obsessive-compulsive symptoms, but the association was significantly stronger for the tendency to seek proxies for internal states. While limited by the sole reliance on the parent-report, the present study shows that the tendency to seek proxies for internal states could help clarify the developmental processes involved in the onset of obsessive-compulsive symptoms during childhood and that sensory sensitivity may be important to consider in this process.