(CNN) -- The American Psychological Association concluded Wednesday that there is little evidence that efforts to change a person's sexual orientation from gay or lesbian to heterosexual are effective.
In addition, the 138-page report -- covering 87 peer-reviewed studies -- said that such efforts may cause harm.
"Contrary to claims of sexual orientation change advocates and practitioners, there is insufficient evidence to support the use of psychological interventions to change sexual orientation," said Judith M. Glassgold, chairwoman of the task force that presented the report at the group's annual meeting in Toronto, Canada. The Washington-based association represents more than 150,000 members.
"At most, certain studies suggested that some individuals learned how to ignore or not act on their homosexual attractions. Yet, these studies did not indicate for whom this was possible, how long it lasted or its long-term mental health effects. Also, this result was much less likely to be true for people who started out only attracted to people of the same sex."
In response, the group's governing Council of Representatives passed a resolution Wednesday urging mental health professionals not to recommend to their clients that they can change their sexual orientation through therapy or any other methods.