For more than 30 years I have been involved in efforts to improve the lives of those with mental illnesses. During that time, unprecedented knowledge has been gained in understanding mental health. The past decade was a particularly exciting time for the field because we achieved greater recognition of the fact that most mental illnesses are biologically based, just as other physical illnesses. We know that, although family and social conditions interact in important ways with biological functioning, mental illnesses are not the result of weak will or misguided parenting, and we have learned that it is best to use approaches for studying and understanding mental illnesses that integrate each of these constructs.

Unfortunately, although much progress has been made in recent years, depression remains one of the most common and disabling mental illnesses. According to the World Health Report 2001, depression was the fourth leading cause of disability for all diseases in 2000 as measured by disability-adjusted life years, or DALYs, and if current trends continue, it is estimated it will become the second leading cause of disability in 2020.

The World Health Organization also reports that the illness is more common in women than in men. These statistics are distressing. Although the gap in depression rates between women and men has been narrowing, it is tragic that so many people continue to suffer unnecessarily.