Age at onset of generalized anxiety disorder in older adults.

OBJECTIVES: To investigate the distribution of age at onset of generalized anxiety disorder (GAD) as well as the possible differences in demographic and psychosocial risk factors, the comorbidities of other psychiatric disorders, health status, and healthcare utilization in respondents suffering from early onset GAD (<50 years) and late-onset GAD (> or =50 years) in adults aged 55 or above.

DESIGN: Cross-sectional observational study.

SETTING: The National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) (2001-2002), a national representative survey of the noninstitutionalized U.S. household population.

PARTICIPANTS: The 439 respondents aged 55 or above who participated in the NESARC and were found to have lifetime GAD.

MEASUREMENTS: The Alcohol Use Disorder and Associated Disabilities Interview Schedule--DSM-IV version was used to assess psychiatric disorders, and the Medical Outcomes study 12-item Short Form questionnaire was included.

RESULTS: The distribution of age at onset appeared normally distributed for respondents with current or lifetime GAD. Among respondents with lifetime GAD, early-onset cases tended to be younger with a higher education level and to have a significantly higher prevalence of panic disorder (current and lifetime), lifetime social phobia, current bipolar I disorder, lifetime alcohol abuse or dependence, or lifetime nicotine dependence than late-onset cases. In addition, respondents presenting with late-onset GAD were more likely to report hypertension and poor health-related quality of life than those with early-onset GAD.

CONCLUSION: About half of the older adult respondents with GAD reported a late onset and, among those with lifetime GAD, late-onset GAD was distinguished from early-onset GAD by a more frequent association with the presence of hypertension and a poorer health-related quality of life.