Background: Although panic disorder (PD) begins typically in adulthood, an earlier onset is not uncommon. Recent studies on early-onset PD indicate that this subgroup of patients may display distinct clinical characteristics.
Objective: To compare a subgroup of early-onset PD patients with the rest of the sample.
Method: A consecutive series of 442 patients with PD were included. Family histories were investigated, and clinical assessment employed the following instruments: Hamilton's scales, Global Functioning Scale, Marks-Mathews' Fears and Phobia Scale, and Panic-Associated Symptom Scale. The age threshold for 'early-onset' was considered at 18 years.
Results: A total of 45 patients (10.2%) exhibited early-onset PD, with a mean age at onset of 14.6. They were younger and had a longer duration of illness than later-onset patients. No differences were found in severity of panic symptoms, anxiety or depressive symptoms, and social functioning. They had more comorbidity with simple phobia, social phobia, and substance dependence. Rates of PD among first-degree relatives were higher in the early-onset group.
Conclusion: Early-onset PD patients displayed a greater familial loading, but clinical severity of their panic-agoraphobia symptoms was not higher. Comorbidity was greater with phobic and substance-related disorders.