Comorbidity between drug misuse and mental disorders affects negatively in the prognosis of psychistric illness, so it´s important to guarantee drug abstinence at least during hospitalization. This is even more significant in a medium stay unit because patients are more serious and resistant to treatment.

In February 2003, a multidisciplinary group was formed to evaluate the situation of drug use in a psychiatric hospital and a drug screening protocol was then created.

We evaluate if with the protocol, drug use decreases during hospitalization in a medium stay unit in a psychiatric hospital.

It is compared drug use (positive results in urine samples) from 2000 to 2002 (before protocol: urine samples collected when there´s drug misuse suspicion) with the period after the protocol was enforced (from 2003 to 2006). In the protocol urine samples are collected when there´s a past misuse history, consumption suspicion, randomly and every time they leave for home.

It is proved that drug use decreases during hospitalization since the new protocol came into force.

The introduction and exhaustive completion of a protocol designed to decrease drug misuse in a psychiatric hospitalization unit, provokes a high reduction of drug use, so we think it´s convenient to generalize this kind of measures.