Smoking is an important health problem associated with different medical and psychiatric disorders. A high prevalence of smoking has been described in psychiatric patients. Our objective was to determine the prevalence of smoking in inpatients admitted to a psychiatric hospitalisation unit in a general hospital, and to study the possible differences in this prevalence according to the different psychiatric diagnoses.

A retrospective analysis of the medical records and discharge reports of the 659 patients admitted to our psychiatric hospitalisation unit during three consecutive years (2003-2005) was carried out.

At the time of their admission, 70.2% of our patients were smokers. This percentage reached 97.2% among patients with substance-use disorders (SUDs), and 95.5% among patients with dual diagnosis. However, only 48.6% of patients without concurrent SUDs were smokers; this difference reached statistical significance (p<0.001). According to psychiatric diagnosis, significant differences were also found regarding the percentage of smokers: 83.0% in schizophrenia, 80.0% in schizophreniform disorder, 70.7% in bipolar disorder, 29.3% in major depressive disorder and 56.8% in other disorders (p<0.001).

Although smoking prevalence among psychiatric patients is higher than in the general population, differences were found between the various psychiatric diagnoses. Thus, the prevalence of smoking was highest among psychotic patients and among those with concurrent use of other substances, whilst depressive patients had rates of smoking similar to those of the general population.