Associations with subsyndromal panic and the validity of DSM-IV criteria.

The purpose of this study was to compare subsyndromal panic--infrequent panic (IP) and limited symptom attacks (LSA)--with panic disorder (PD) in psychiatric comorbidity, quality of life (QOL), and health care utilization and to assess validity of DSM-III-R criteria for panic disorder. Randomly selected adults were screened for the presence of PD, IP, and LSA by using the Structured Clinical Interview of the DSM-IIIR. Subjects with panic symptoms and matched controls completed a structured interview concerning comorbidity, QOL, and utilization. Although PD and IP subjects reported more psychiatric comorbidity than did LSA subjects, LSA subjects had more comorbid conditions than did controls. Differences in utilization were limited to PD subjects. Although subsyndromal panic was associated with poor QOL, panic-related work disability was primarily seen in PD subjects. Regression analyses demonstrated little difference between LSA and IP subjects, but interaction analysis supported the distinction between LSA and full-blown panic attacks. Compared with controls, LSA and IP subjects had more psychiatric comorbidity. PD subjects also had poorer QOL and more utilization. Interaction analysis supports DSM-IV criteria for panic disorder.