The first thing you need to do is to review your school's policies and procedures for accommodating special needs students. Emotional disabilities are normally handled within a standard framework for accommodations. Typically, the disabilities office in your school works with the student and appropriate medical professionals to develop an accommodation plan for each special needs student and your task to is follow that. If the student's behavior issues disrupt the class or interfere with other students' learning, you need to meet with parents, administrators, and the disability office to revise the accommodation plan.
The main thing you should NOT do is play at being a psychologist and try to work this out on your own, independent of expert assistance and existing administrative frameworks. Just as when a student is physically injured, you wouldn't trying performing brain or open heart surgery on your own for a quick fix during class time, so also you need to work with experts through established procedures concerning emotional issues. With all the issues of teen suicide and school violence, handling things on your own can have very bad consequences (and personal liability for you if you do not follow correct procedures).
Another practical issue: every teacher should have professional liability insurance, just in case something does go wrong and you are listed as a party in a law suit.