Some insurance plans strictly limit coverage for mental health treatment, for instance, paying for only a small number of therapeutic sessions or...

The federal Mental Health Parity and Addiction Equity Act, passed in 2008, states that insurance companies must cover mental health and substance-abuse issues to the same degree that they cover physical care. However, many insurance companies have limits on coverage for mental health care. In addition, the law does not require insurance companies to have mental health care benefits but only states that if they do, they must cover mental health to the same degree...

The federal Mental Health Parity and Addiction Equity Act, passed in 2008, states that insurance companies must cover mental health and substance-abuse issues to the same degree that they cover physical care. However, many insurance companies have limits on coverage for mental health care. In addition, the law does not require insurance companies to have mental health care benefits but only states that if they do, they must cover mental health to the same degree as they cover physical health. In addition, insurance companies can exclude certain diagnoses.

This situation is dire because one in four Americans faces mental illness each year. The reason that insurance companies deny or limit coverage is partly cost. Some mental health and substance abuse issues are chronic, meaning that their treatment is indefinite. Treating these disorders is very expensive yet necessary because, if they are left untreated, mental disorders can not only cause pain and suffering for the individual affected but also can affect their loved ones, employment, and even health. There is evidence, for example, that serious depression has health effects (see "Depression, chronic diseases, and decrements in health: results from the World Health Surveys" by Saba Moussavi, Somnath Chatterji, Emese Verdes, Ajay Tandon, Vikram Patel, and Bedirhan Ustun). In other words, if they are untreated, mental health issues can have physical consequences. 

The reason that insurance companies deny mental health care is that it is expensive. It is also difficult to determine how much care people need to recover from mental illness and to decide when patients are better and can end their care.