Abstract
Background/Objective: The heterogeneous clinical presentations of individuals with Autism Spectrum Disorders (ASD) pose a significant challenge for sample characterization. Therefore the main goal of DSM-5 must be to identify subgroups of ASD, including comorbidity disorders and severity. The main goal of this study is to explore the psychiatric comorbidities and the severity of symptoms that could be relevant for the phenotype characterization in ASD and also to compare these results according to the different classification criteria between the DSM-IV-TR and the DSM-5. Method: A comparative study of severity and psychiatric comorbidities was carried out between a sample of participants that only met criteria for Pervasive Developmental Disorder (PDD) according to the DSM-IV-TR and a sample of participants that also met ASD criteria according to DSM-5 classification. The recruitment of children was via educational (N = 123). The psychiatric symptoms, comorbid disorders and severity of symptoms were assessed through The Nisonger Child Behavior Rating Form, clinical interview and The Inventory of Autism Spectrum Disorder, respectively. The psychiatric comorbidities considered were: anxiety, eating behavioural problems, self-aggressiveness, hetero-aggressiveness, self-harm, obsessive compulsive disorder and attention deficit and hyperactivity disorder. Results: Statistically significant differences between both groups were found regarding obsessive compulsive disorder, eating behavioural problems and severity. Conclusions: The results support the hypothesis that patients who meet the DSM-5 criteria have more severe symptoms, not only regarding the core autistic symptoms but also in relation with psychiatric comorbidities.