Be sure that your charge is never left alone until all severe withdrawal symptoms are gone. The atmosphere should be calm. Lights should be on, but not too bright. Take any mention of suicide seriously and get professional advice. If your charge begins to cheer up after talking about suicide, this is not necessarily a good sign.
More people commit suicide emerging from depression than while depressed.
Forget about lectures and sermons. It's important that he or she feels worthy of your efforts and attention. Be a good listener, but don't try to give a lot of advice. Do give direct accurate answers to the best of your ability, and don't be evasive. Be careful not to act as though you don't believe or trust your patient.