EN
Comorbidity, co-occurence of disorders are terms used to describe symptoms, accompanying psychopathological syndromes, or individual incorrect traits of behavior. It is the presence of one or more diseases (disorders) in addition to the basic disease (disorder) or the effect of additional disorders. In children with developmental disorders, there is a specific model of evolution and a tendency to develop not only one but several disorders. This phenomenon is particularly evident among people with autism spectrum disorders. It is even assumed that the comorbidity of diseases and disorders in this population is more frequent, and incorrect development in only one sphere is rare. The issues of the relationship between the spectrum of autistic disorders and other related disorders are extremely complex and involve many diagnostic dilemmas, both due to the uncertain results of scientific studies evaluating the prevalence of co-occurring disorders and due to the unusual heterogeneity observed within the autism spectrum. According to the latest data, 70% of people with autism spectrum may have one coexistent disorder, and 40% of this population has two or more additional disorders (DSM - 5, 2013). The content of the article is the analysis of comorbidity and co-occurence of disorders in people with autism spectrum, their developmental conditions and diagnostic difficulties resulting from the complexity of the pathomechanism of this phenomenon.