BACKGROUND: Panic disorder (PD) is a common illness associated with hi
gh levels of disability and with a high utilisation of non-psychiatric
health services which is inefficient in most cases, A better understa
nding of the clinical subtyping of PD may improve diagnosis both in ps
ychiatric and medical settings. The present study is aimed at assessin
g the frequency, factorial grouping and comorbity of PD symptoms in a
naturalistic sample of patients. PATIENTS AND METHODS: All consecutive
cases of PD (n = 442) who contacted with two outpatient clinics in Ba
rcelona (Spain) were assessed by two experienced interviewers, Assessm
ent instrument included SCID-UP-R interview and inventory of panic sym
ptoms based on DSM-III-R. RESULTS: Palpitations (86.7%), shortness of
breath (76.5%), fear of dying (69.9%) and dizziness (63.6%) were the m
ost frequent and intense symptoms reported by the PD patients. The pri
ncipal component analysis revealed four factors which explained the 56
% of the variance: ''cardiorespiratory'' (23.2%), ''depersonalization-
derealization'' (15.8%), ''vestibular'' (10%) and ''mixed'' (7%). CONC
LUSIONS: The frequency of presentation of symptoms was similar to othe
r studies. However some disimilarities appeared that may be attributed
to transcultural differences as well as terminological problems and t
he range of symptoms assessed, Factors found in the present study supp
ort the clinical subtyping of PD in 3 groups characterised by cardiore
spiratory symptoms and fear of dying, cognitive symptoms (depersonaliz
ation-derealization) and vestibular symptoms such as dizziness and fai
ntness.