Suicide is one of the leading causes of premature death among people with psychotic disorders. However, little is known about treating suicide in delusional disorder.

To investigate effectiveness of PPLAI in delusional disorder (DD) patients.

To compare effectiveness of PPLAI vs,other atypical antipsychotics (OAA) in psychopathology and suicidality.

Prospective observational study including 45 DD outpatients (DSM-IV-RT) attended at the Department of Psychiatry (Hospital Clinic- BCN) from 2008 to 2012 and followed up for 6 months. Demographic and clinical variables were recorded. Hamilton Rating Scale for Depression-17 (HRSD-17), PANSS for psychopathology, Personal and Social Performance Scale (PSP) and Columbia Suicide Severity Rating Scale (C-SSRS) were assessed at baseline and after 6 months. The sample was divided into four groups according to which treatment they received: oral risperidone, Risperidone Long Acting Injection (RLAI), OAA and PPLAI. For comparisons, Kruskal-Wallis and Chi-square tests were used.

Eighty-two per cent were women. Mean age (SD) at onset: 46.9(11.8) years. 6 patients received oral risperidone, 23 OAA, 7 RLAI and 9 were treated with PPLAI. No statistically significant differences were found regarding demographic features, motives leading for consultation, depressive comorbidity and antidepressant prescription. After 6 months, patients treated with PPLAI presented lower frequency of ideation (0% vs.11.1%;p=0.027) and suicidal behaviour (0% vs.2.2%;p=NS). The group receiving PPILD presented a significant increase in functionality (PSP) (p=0.046) and an improvement in PANSS negative subscale scores (p=0.017).

Patients receiving PPLAI showed a decrease in suicidality, an improvement in psychotic symptoms and functionality.