The revision of DSM-5 and the mental disorders chapter of ICD-11 are informed by concepts of mental disorders, which share some features, and some differences.

To review the similarities and differences in concepts of ICD-11 and DSM-5

By describing the classification of psychotic disorders, we exemplify the different conceptual approaches of both classification systems.

Review of the classification of psychotic disorders in DSM-5 and ICD-11 and the underlying concepts of mental disorders.

Both systems take an anosological approach and base the classification of mental disorders on psychopathology, which takes centerstage in the clinical evaluation for classification purposes. A major difference is the role of functional impairments, which are mandatory in DSM-5, but not ICD-11. Time course criteria were harmonized and dimensional assessments were introduced in both systems. Differences in duration criteria lead to different approaches regarding brief psychotic disorders. Attenuated psychotic symptoms did not receive full diagnostic status.

Neither DSM-5 nor ICD-11 have introduced neurobiological or genetic factors into the classification of psychotic disorders. Both systems take steps towards dimensional symptom assessments, with different practical operationalizations. Some differences prevail regarding time course criteria and the handling of brief psychotic disorders, which may indicate different concepts of chronicity underlying these decisions. An important aspect was the non-inclusion of attenuated psychotic symptoms syndrome among the mental disorders, indicating that the border towards normality is still uncharted terrain in both classification systems and open for discussions about concepts of subclinical or otherwise dimensional ratings of subdiagnostic symptoms in the general population.