Dual disorders (DD) is a common clinical reality, associated with higher degree of complexity. Unfortunately there are few studies on this field. The diagnostic process is difficult and DD has been associated to more severe condition and worse outcomes. Clinically is associated to more relapses, higher suicide risk and less adherence. Dual diagnosis requires complex therapeutic approaches to be able to adapt the treatment to the dual nature of the problem. The treatment should including medical, psychopathologic and social approach. Polymedications and polydrug use is very common, so it is important to understand the effects of the drug and the drug interactions that may be observed during the treatment. There are lacks of guidelines and off-label prescription is common. A lack of resources has been described. Clinicians should be made efforts for detecting DD patients and for adapting treatments.