What are the key diagnostic criteria for delusional disorder according to the DSM-5?

The key diagnostic criteria for delusional disorder according to the DSM-5 include the presence of one or more delusions lasting for at least one month. These delusions are typically non-bizarre, meaning they involve situations that could occur in real life, such as being followed, poisoned, infected, loved at a distance, or deceived by a spouse or lover.

Unlike schizophrenia, the criteria specify that apart from the impact of the delusions, functioning is not markedly impaired and behavior is not obviously bizarre or odd. Hallucinations, if present, are not prominent and are related to the delusional theme.

The disturbance cannot be better explained by another psychotic disorder, mood disorder with psychotic features, substance use, or a medical condition. The duration must be at least one month, and the symptoms must cause significant distress or impairment in social or occupational functioning.

DSM-5 also categorizes delusional disorder into subtypes based on the predominant delusional theme, such as persecutory, jealous, erotomanic, grandiose, somatic, mixed, or unspecified types.

This diagnostic framework reflects the clinical features of paranoia and delusional content as historically represented and refined through DSM editions, emphasizing the persistence and specificity of delusions without the broader psychotic symptoms seen in schizophrenia (Nakahara et al., 2003; Biedermann and Fleischhacker, 2016; Kendler, 2017) ¹ (Nakahara et al., 2003) (Biedermann and Fleischhacker, 2016) (Kendler, 2017).