title: A three-year follow-up study of patients with the respiratory subtype of panic disorder after treatment with clonazepam.
abstract: The demographic, clinical and therapeutic features of the respiratory subtype of panic disorder (PD) versus the non-respiratory subtype were studied in a prospective design. Sixty-seven PD outpatients (DSM-IV), who had previously been categorized into respiratory (n=35) and non-respiratory (n=32) subgroups, were openly treated with clonazepam for a 3-year period. The principal measure of efficacy was the number of panic attacks, obtained from the Sheehan Panic and Anticipatory Anxiety Scale. In the first 8 weeks of treatment (acute phase), the respiratory subtype group had a significantly faster response to clonazepam. During the follow-up (weeks 12-156), the two subgroups did not differ significantly in the number of panic attacks experienced from baseline to end point. Patients in the respiratory subtype were characterized by a later onset of disorder and a family history of PD. Patients in the non-respiratory subgroup had a significantly higher number of past depressive episodes than those in the respiratory subgroup. The respiratory subgroup had a faster response after 8 weeks of treatment and an equivalent response in the 3-year follow-up period. Clonazepam had a sustained therapeutic effect over the entire treatment period.
authors.affiliation: Laboratory of Panic & Respiration, Institute of Psychiatry, Federal University of Rio de Janeiro, R. Visconde de Pirajá, 407/702, Rio de Janeiro-RJ-22410-003, Brazil. antonionardi@terra.com.br
authors.forename: Antonio E
authors.initials: AE
authors.lastname: Nardi
authors.forename: Alexandre M
authors.initials: AM
authors.lastname: Valença
authors.forename: Isabella
authors.initials: I
authors.lastname: Nascimento
authors.forename: Fabiana L
authors.initials: FL
authors.lastname: Lopes
authors.forename: Marco A
authors.initials: MA
authors.lastname: Mezzasalma
authors.forename: Rafael C
authors.initials: RC
authors.lastname: Freire
authors.forename: André B
authors.initials: AB
authors.lastname: Veras
authors.forename: Walter A
authors.initials: WA
authors.lastname: Zin
authors.forename: Marcio
authors.initials: M
authors.lastname: Versiani
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use*; D002998:Clonazepam / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D018757:GABA Modulators / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000235:genetics / Q000523:psychology; D011446:Prospective Studies; D012119:Respiration / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D000927:Anticonvulsants; D018757:GABA Modulators; D002998:Clonazepam