Several studies which focus on the clinical study of the panic disorder have shown its clinical variety, subject to individual variations and which, up to a certain point, may justify a different response to the treatment used. In this sense, but focused on the presence of the depersonalization symptom we have directed our study to see if depersonalization is associated to socio-demographic characteristics, clinical and or personality traits which allow us to differentiate two sub-types of this disorder. Twenty-eight patients with panic disorder completed a structured interview which included a list of symptoms from the Structured Clinical Interview for DSM-III -Upjohn version, together with impairment in social or occupational functions. Fisher's Exact Test and Student's T test were used to analyse the results and showed for depersonalization an earlier onset (p < 0.05) and a more important impairment (p = 0.0021). Thus, the most important conclusion we have reached is an association between depersonalization, an earlier onset of the panic disorder and a more important impairment.