Differences in diagnostic subtypes among patients with late and early onset of a single depressive episode

It is unclear whether patients with late onset and patients with early onset present with different subtypes of depression. The aim of the study was to compare the prevalence of subtypes of ICD-10 single depressive episodes for patients with late onset (age >65 years) and patient with early onset (age < or = 65 years) in a nationwide sample of all patients discharged from psychiatric in- or outpatient settings.

All patients who got a diagnosis of a single depressive episode in a period from 1994-2002 at the end of the first outpatient treatment or at the first discharge from psychiatric hospitalisation ever in Denmark were identified in a nationwide register.

In total, 18.192 patients were given a diagnosis of a single depressive episode at the first outpatient contact and 8.396 patients were given a diagnosis of a single depressive episode at the first psychiatric hospitalisation ever. Patients with late onset were more often women, more often presented with a severe depressive episode and more often with psychosis than patients with early onset, in both inpatient and outpatient treatment settings. No differences were found between patients with late and patients with early onset in the prevalence of depression with or without melancholic symptoms-in either of the treatment settings.

Patients with a late onset first depressive episode are more often women and are clinically characterised by more severe depressions and a higher prevalence of psychosis than patients with early onset.