Task: Question Answering
Input (English): 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.
Output (English): 1