Evidence suggests a relationship between sleep disturbances and suicidal ideation. The temporal appearance of insomnia has been proposed as a warning sign of imminent suicidal acts. However, there is little information on the temporal relation of insomnia with acts of deliberate self-poisoning (DSP) in particular.

This study aimed to identify the insomnia prevalence in DSP patients and test its predictive value in relation to current psychiatric diagnosis and history of previous DSP acts.

Seventy consecutive patients with DSP admitted from February to September 2010 into three general hospitals had a psychiatric consultation and their sleeping pattern during the week before the DSP act was assessed using the Athens Insomnia Scale.

Patients, with a mean age of 34 ± 2 years, predominantly women (70%), were diagnosed with personality disorders (68%), depression (22%) and psychosis (10%). The overall insomnia prevalence was 69%. A chi-square analysis showed that patients with an Axis I diagnosis were significantly more likely to present insomnia than patients with an Axis II diagnosis. Interestingly, when the number of previous DSP acts was included into the analysis, patients with an Axis I diagnosis with and without previous DSP acts had an equal prevalence of insomnia. On the contrary, in patients with an Axis II diagnosis and previous DSP acts, insomnia was three times more prevalent than in those with no previous DSP acts.

These results suggest that insomnia may be a valid proximal warning sign, particularly in patients with personality disorders and previous DSP acts.