Most people who are alcoholic would just be alcoholic, with drug problem would only have drug problem, or with psychiatric problem would only have psychiatric problem.
But there are people who got dual problems. They can be alcoholic and at the same time is taking drugs, or maybe is taking drugs and has a depression problem. People became health problematic because of personal problems or because of their environment. For people with such case, there are dual diagnosis treatment centers that can help people undergo treatment process.