In recent years, NIMH has introduced a new generation of "real-world" clinical studies. They are called "real-world" studies for several reasons. Unlike traditional clinical trials, they offer multiple different treatments and treatment combinations. In addition, they aim to include large numbers of people with mental disorders living in communities throughout the U.S. and receiving treatment across a wide variety of settings. Individuals with more than one mental disorder, as well as those with co-occurring physical illnesses, are encouraged to consider participating in these new studies. The main goal of the real-world studies is to improve treatment strategies and outcomes for all people with these disorders. In addition to measuring improvement in illness symptoms, the studies will evaluate how treatments influence other important, real-world issues such as quality of life, ability to work, and social functioning. They also will assess the cost-effectiveness of different treatments and factors that affect how well people stay on their treatment plans.