The impact of comorbid depression: an exploration of comorbidity and inter-rater reliability of the DSM-5 K-SADS-PL among depressed and non-depressed youth

Depressive disorders are among the most prevalent mental health disorders affecting youth. Comorbidity is very high and affects the course, severity, and treatment outcome of the disorder and increases the risk of suicide. Screening and identification of depression and comorbid conditions is therefore a very important factor when it comes to clinical decision-making and appropriate course of treatment. The aim of this study was twofold; to evaluate the inter-rater reliability of the DSM- 5 Schedule for Affective Disorders and Schizophrenia–Present and Lifetime Version (K-SADS-PL) and to compare inter-rater reliability of diagnoses among depressed and non-depressed youth. Participants consisted of 94 children and adolescents aged 6 to 18 years seeking treatment at two outpatient clinics in from January to March of 2019 to 2021. Inter-rater reliability on diagnoses was measured by using Cohen’s kappa. Agreement ranged from fair to excellent for all diagnoses made and was relatively equal across groups. The largest discrepancy was within anxiety disorders. Agreement for specific phobia was only fair in the depressed group and good in the non-depressed group. For panic disorder, however, agreement was better in the depressed group. Social anxiety disorder also had a relatively higher agreement in the depressed group. The findings suggest that the DSM-5 K-SADS-PL can be used as a reliable diagnostic tool and can reliably identify comorbid disorders among youth suffering from depressive disorders