Prevalence of externalising disorder comorbidities in adolescents: a systematic review and meta-analysis protocol

INTRODUCTION: Externalising disorders are some of the most prevalent problems in childhood and particularly during adolescence that can change into more severe psychopathology in adulthood if left unattended. In the research literature, these disorders include attention deficit/hyperactivity disorder, oppositional/defiant disorder, conduct disorder and substance use disorders. The comorbidity prevalence of these disorders is significant and cannot be considered a random factor. The dimensional structure of psychopathology has always been studied by researchers to address disorder comorbidities and aetiology. There has always been controversy over the number of spectra and the lower levels. Currently, the new top-down, Hierarchical Taxonomy of Psychopathology model conceptualising psychopathology is being used, which is a dimensional classification system for the different spectra of psychopathology based on a combination of conceptual modelling and factor analysis of symptoms. This systematic review investigates the comorbidity prevalence of spectra of externalising disorders to provide valuable information and feedback on this model. METHODS AND ANALYSIS: This systematic review will include all the studies conducted from 1/1/1990 to 1/12/2020 to examine the prevalence and comorbidity of each of the externalising disorders in the general population, schools and outpatients using any instrument (questionnaires or interviews). There will be no language restrictions in selecting the studies. The studies are age restricted and must be conducted on adolescents only, but there are no restrictions on the gender and nationality of the participants. ETHICS AND DISSEMINATION: This systematic review is based on previously published articles and therefore will not require ethical approval. The results of the systematic review will be disseminated as publication in a peer-reviewed journal and conference presentation. PROSPERO REGISTRATION NUMBER: CRD42022327629.