Homosexual and bisexual men and women may face higher risks of depression, substance abuse and suicidal behavior than heterosexuals do, a new study suggests.

In an analysis of 25 past studies on sexual orientation and mental health, UK researchers found that across the studies, gay, lesbian and bisexual adults were at least 50 percent more likely than heterosexuals to have a history of depression or an anxiety disorder.

They also have similarly elevated risk of alcohol problems or other forms of substance abuse, and were more than twice as likely as heterosexuals to have attempted suicide at some point in their lives.

The findings, published in the journal BMC Psychiatry, strengthen evidence from smaller studies that gay, lesbian and bisexual people have a relatively higher rate of mental health problems.

However, none of this means that homosexuality is itself some type of disorder that gives rise to poorer mental health, stressed lead researcher Michael King, of University College London.

This study could not examine the reasons for the higher-than-expected rate of mental disorders and substance abuse. However, King told Reuters Health, it is likely that lifelong stress is involved.

Even in relatively liberal societies, he said, gay, lesbian and bisexual people face both overt and subtle discrimination. They may also have to deal with social exclusion and rejection by their own families.

It’s important, King said, for healthcare providers to be aware that homosexual and bisexual patients have a relatively higher risk of mental health disorders. On the other hand, he added, they should not assume that such problems in these patients are necessarily related to their sexuality.

According to King, therapists can have a tendency to automatically see the sexuality as the issue - rather than, for example, the depression itself.

“This occurs quite frequently,” he noted, “much to the irritation of many (lesbian, gay and bisexual) people who seek therapy.”

SOURCE: BMC Psychiatry, August 18, 2008.