Executive Summary

A sample of 201vSydney injecting drug users (IDU) were interviewed about their use of antidepressants. The prevalence of both lifetime and recent antidepressant use was high. Forty percent of subjects had used antidepressants, 21% in the preceding 6 months.

The use of both SSRis and tricyclic antidepressants was common. Similar proportions of subjects had ever used tricyclics (26%) and SSRis (24%), with 8% reporting use of a MAOI. While lifetime exposure to the two major antidepressant classes were almost identical, recent use favoured the SSRis. SSRis were the class last used by 50% of current users, and were the antidepressants most often used by 48% of this group. Despite the predominance of SSRis among current users, tricyclics were still widely used. Nearly a half (45%) of current antidepressant users had used tricyclics during the preceding six months.

The use of antidepressants appeared to be sporadic. The longest continuous use of antidepressants reported by subjects was one month, with females reporting longer maximum use (3 mths v 19 days). Current antidepressant users reported a median of 25 days continuous use in the preceding six months. Seventeen percent of subjects who had been prescribed antidepressants reported that they had exceeded the prescribed dosage on the last use occasion. The injection of antidepressants was rare, with only 3 subjects reporting ever having injected the drugs.

Ninety three percent of current antidepressant users had used other drugs in combination with antidepressants in the preceding six months, and a half had always combined the antidepressants with other drugs. The main drugs used in combination were heroin, methadone, benzodiazepines and alcohol, all CNS depressants.

Procurement of antidepressants was not solely through medical practitioners, with only 52% of current antidepressant users reporting having always obtained these drugs through doctors in the preceding six months. Only 46% of those who continued antidepressant use nominated depression as the main reason for doing so, with 12% reporting that they used the drugs for intoxication.

Antidepressant use was associated with higher levels of polydrug use, poorer health higher levels of psychiatric distress, and a greater risk of heroin overdose. The excess risk of overdose was specifically associated with tricyclics, rather than SSRis.