Several studies have found that cigarette smoking increases the risk of panic attacks and panic disorder in young people. While the mechanism of how smoking increases panic attacks is not fully understood, a few hypotheses have been derived. Smoking cigarettes may lead to panic attacks by causing changes in respiratory function (e.g. feeling short of breath). These respiratory changes in turn can lead to the formation of panic attacks, as respiratory symptoms are a prominent feature of panic. Respiratory abnormalities have been found in children with high levels of anxiety, which suggests that a person with these difficulties may be susceptible to panic attacks, and thus more likely to subsequently develop panic disorder.

About 30% of people with panic disorder use alcohol and 17% use other psychoactive drugs. While alcohol initially helps ease panic disorder symptoms, medium- or long-term alcohol abuse can cause panic disorder to develop or worsen during alcohol intoxication, especially during alcohol withdrawal syndrome. Most stimulant drugs (caffeine, nicotine, cocaine) would be expected to worsen the condition, since they directly increase the symptoms of panic, such as heart rate. Cannabis commonly precipitates panic in panic patients.