Comorbidity between drug consumption and several psychiatric disorders is a topic of increasing interest. It´s known that between 30% and 80% of psychiatric inpatients use drugs, and these patients often show worse prognosis, for what their identification turns out to be one of the biggest challenges for the clinician.

Based on clinical practice in a psychiatric hospital, we investigate the possible existence of underdiagnosis for misuse of drugs in psychiatric inpatients.

It is analyzed, retrospectively, all admission to a psychiatric hospital in 2000 and 2005, in which diagnosis to the discharge involves drug misuse (dependence, abuse, toxic psychosis). Likewise it´s analyzed laboratory information of drug screening in urine (obtained of every patient suspicion of consumption). Both results are then compared.

Our hypothesis is confirmed, being very scanty the number of diagnosis to the discharge associated with drug misuse, compared to the high prevalence of drug use demonstrated in the laboratory screening.

Although it´s known that drugs are often used by psychiatric patients, clinicians often elude to diagnose it (probably another diagnosis, such as schizophrenia, are so important for us that we don´t pay enough attention to drugs).

This investigation should remind clinicians that drug use is frequent, adds worse prognosis, and must be specifically treated.