age of onset
The age at which an individual first experiences symptoms or meets diagnostic criteria for a psychiatric disorder.
Full Definition
Age of onset is a critical epidemiological variable that indicates when a mental health condition first manifests in an individual's life. This measure helps researchers understand developmental patterns of psychiatric disorders, identify critical risk periods, and plan age-appropriate interventions. Age of onset can be defined as first symptoms, first diagnosis, or first treatment contact, and researchers must specify which definition they use. The distribution of ages of onset varies significantly across different psychiatric conditions, with some disorders typically emerging in childhood or adolescence and others appearing later in life.
Usage
Usage note: Clearly define whether referring to first symptoms, first diagnosis, or first treatment contact.
In Context
- "The median age of onset for bipolar disorder was 18.2 years in this longitudinal cohort." — clinical research findings
- "Researchers examined whether early age of onset predicted more severe illness course." — prognostic study