Scissors, razors, broken glass, knifes ect. Anything sharp enough to break the skin. Now as far as suicide goes, people shoot them selves, hang themselves, or use drugs.

We prevent this by looking for signs of depression or obvious scars on their body. Look for random mood shifts, and getting very defensive on certain topics!

Use of substances that will get you high. (Pot, Cocaine etc) To stop, you must do less and less of the substance you have abused each day until you are down to a very small amount. From there, knowing you don't need it anymore, you can try to avoid contact with all connections to get the substances. Hope I helped.