Dual diagnosis (DD) is the coexistence of a Psychiatric Disorder (PD), and Substance Use Disorder (SUD). The increase of DD observed in recent years has caused serious problems to both public and private services organization.

Our aim is to assess the prevalence and features (including clinical and sociodemographic ones) of DD over a decade, comparing the period 2003–2004 and 2013–2014.

We performed a retrospective study retrieving the medical records of DD patients at their first admission to the Psychiatry Ward AOU “Maggiore della Carità”, Novara, Italy. Sociodemographic and clinical features were recorded. The two groups of patients (2003–2004 vs. 2013–2014) were compared.

In both periods DD patients are usually Italian male, aged 19–40, single. They have usually attended middle school, live with parents, have two or more brothers and/or sisters but no kids. DD patients in 2003–2004 and 2013–2014 showed differences as far as employment and diagnosis are concerned. The first were more frequently employed than the latter: moreover the 2003–2004 patients were more frequently diagnosed with a personality disorder while the 2013–2014 patients had mixed diagnoses. We have found differences in the possible predictors of substance abuse in the two periods, as well.

The identification of changes in the prevalence of first admission DD patients and their clinical and sociodemographic features may help to highlight an evolving pattern of substance use and to identify possible risk factors which may be the target of prevention and treatment approaches.

The authors have not supplied their declaration of competing interest.