Introduction: The objectives of this study were to evaluate the prevalence of drug use in out-patients with panic disorder and their influence in evolution and therapeutic response of panic disorder.
Material and methods: The sample was made up of 79 out-patients diagnosed of panic disorder or agoraphobia with panic disorder according to the ICD-10 criteria and 83 controls from the same center with other psychiatric disorders. Subjects were followed-up for six months.
Results: Prevalence of regular lifetime drug use was: 13 % for alcohol, 52 % for nicotine and 47 % for caffeine. No other drug use was observed. Patients with panic disorder used less caffeine than controls, there being no differences in other drug use. Caffeine use was associated with higher antidepressant dosages.
Conclusions: Thus, prevalence of regular drug use in panic disorder during the lifetime of out-patients with panic disorder was: 13 % for alcohol, 47 % for caffeine use and 52 % for nicotine use. Those with panic disorder use less caffeine than other psychiatric patients, but there were no differences in other drug use. Presence of agoraphobia has no repercussion on consumption. There were no differences in clinical manifestations and treatment responses between users and non-users, but drug use may modify antidepressant dosages.