Poor insight has been associated to positive and negative symptoms in schizophrenia. However, the impact of antipsychotic treatment on insight in delusional disorder (DD) has not well defined.

Our purpose was to investigate the impact of long-acting atypical antipsychotics (PPLAI, RLAI) on insight in DD patients.

We conducted a prospective and observational study by including 60 consecutive cases of DD outpatients, which were followed up for at least 6 months. Outcome variables: Scores in the first three items of the SUMD for Insight, PANSS for psychopathology, HRSD-17 for depression and PSP for functionality. The sample was divided into two groups according to the treatment received: oral or long-acting atypical antipsychotics (RLAI or PPLAI). T and Chi-square tests were used. Insight differences between both groups were investigated by applying Analysis of Covariance.

At baseline, DD patients treated with long-acting injectable antipsychotics had higher scores in awareness of social consequences. Although no statistically significant differences were found, after 6 months of treatment, patients receiving long-acting injectable antipsychotics showed a tendency of improvement of awareness of illness, awareness of the effects of medication and awareness of social consequences. Statistically significant treatment group*PANSS total score interactions were found for awareness for social consequences. After controlling for SUMD baseline and PANSS total scores, DD patients treated with long-acting antipsychotics showed an improvement of awareness of the effects of medications and social consequences.

Patients receiving long-acting injectable antipsychotics showed an improvement in psychotic symptoms and insight dimensions.