Definition: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Input: Question: The presence of a mental disorder and the pathological use of toxic substances: 
 Options:  <1> It refers to the concept of Dual Pathology, a specific type of diagnostic comorbidity. <2> It is a pathological entity that does not exist. <3> It is synonymous with bipolar disorder. <4> It refers to elderly people who simultaneously have two or more mental illnesses. <5> It constitutes a diagnostic label without relevance from the clinical or social perspective.
