Colorado is among roughly half the states that prohibit the practice of trying to change a person’s sexual orientation or gender identity through counseling.

The U.S. Supreme Court agreed on Monday to hear a Christian therapist's challenge on free speech grounds to a Democratic-backed Colorado law banning "conversion therapy" intended to change a minor's sexual orientation or gender identity.

Teens who have experienced gay conversion therapy say the treatment left them anxious, depressed or suicidal, but a Christian counselor wants the high court to declare the prohibitions unconstitutional.