Impulsiveness has an important role in suicide behaviour and substance abuse.

In this context, it's important to assess suicide risk among drug users and to determine which factors play a protective role and which factors increase the risk.

In this study the authors propose to determine the prevalence of actual or past suicidal ideation in a sample of substance users; to determine the prevalence of previous suicidal behaviours in the same sample; and to study the relation with clinical and sociodemographic variables.

The sample included 119 patients with drug addiction behaviours receiving treatment in an inpatient detoxication unit (Unidade de Desabituação do Norte do IDT - Instituto da Droga e das Toxicodependências), admitted between May 2010 and July 2010.

Data was obtained from the patient clinical chart, including the admission protocol form.

SPSS was used for statistical analysis.

The results founded were:

• 18,5% (n = 22) had previous suicidal ideation at least once in their lifetime.

• 2,5% (n = 3) had suicidal ideation at admission.

• 10,9% (n = 13) had previous suicidal attempts.

According to literature, in general population, lifetime prevalence of suicidal ideation is 10–18% and history of suicidal attempt is 3–5%.

In the studied sample, suicidal ideation during lifetime is slightly raised (18,5%) and history of suicidal behaviours is strongly higher (10.9%).

These data suggest a raised suicidal risk in drug abuse population, probably reflecting a higher impulsiveness in this population.