Hyperprolactinemia is a frequent side effect observed in patients treated with anti-psychotic drugs. The frequency of clinical signs usually correlates with elevated serum prolactin levels.

To estimate the prevalence of hyperprolactinemia among patients treated with a single anti-psychotic and specify the risk factors for its occurrence.

Cross-sectional study performed in a period of 6 months in the psychiatric department of Mahdia's hospital, for all patients seen in the consultation and treated with a single anti-psychotic for 12 weeks, with a stable dose, and meeting the inclusion and exclusion criteria of the study. Prolactin blood tests have been performed and confirmed by a second one in case of abnormality objectified in the first lab test results. A magnetic resonance imaging (MRI) was intended for patients with prolactin levels greater than 150 ng/mL.

Ninety-two patients were gathered. Prevalence of hyperprolactinemia was 34.8% of which 7.6% had prolactin levels greater than 150 ng/mL. Two macroadenomas’ cases were detected. The analytical study found 7 factors significantly correlated with hyperprolactinemia, which are: female sex, substance use, the presence of side effects, prescription of atypical anti-psychotics, the anti-psychotic treatment prescribed: haloperidol/amisulpride, doses of anti-psychotic greater than 1000 mg equivalent to chlorpromazine and the combination of psychotropic drugs.

Prolactin blood test should be a systematical analysis for all patients treated with anti-psychotics, to prevent the short and long term side effects.

The authors have not supplied their declaration of competing interest.