[Subtyping panic disorders according to their symptoms]

Panic disorder (PD) is a common illness associated with high levels of disability and with a high utilisation of non-psychiatric health services which is inefficient in most cases. A better understanding of the clinical subtyping of PD may improve diagnosis both in psychiatric and medical settings. The present study is aimed at assessing the frequency, factorial grouping and comorbidity of PD symptoms in a naturalistic sample of patients.

All consecutive cases of PD (n = 442) who contacted with two outpatient clinics in Barcelona (Spain) were assessed by two experienced interviewers. Assessment instrument included SCID-UP-R interview and inventory of panic symptoms based on DSM-III-R.

Palpitations (86.7%), shortness of breath (76.5%), fear of dying (69.9%) and dizziness (63.6%) were the most frequent and intense symptoms reported by the PD patients. The principal component analysis revealed four factors which explained the 56% of the variancel "cardiorespiratory" (23.2%), "depersonalization-derealization" (15.8%), "vestibular" (10%) and "mixed" (7%).

The frequency of presentation of symptoms was similar to other studies. However some disimilarities appeared that may be attributed to transcultural differences as well as terminological problems and the range of symptoms assessed. Factors found in the present study support the clinical subtyping of PD in 3 groups characterised by cardiorespiratory symptoms and fear of dying, cognitive symptoms (depersonalization-derealization) and vestibular symptoms such as dizziness and faintness.