Suicide, for the most part, isn't about being weak. Along with depression, it's mainly an effect of certain parts of the brain being underdeveloped (I believe the frontal cortex, which deals with consequences of decision making). In many ways it isn't even the person's fault that they commit suicide, as they often let other people know. Do what you can to help those suffering through depression if they let you know what's going on, and if they don't, make sure you don't abuse your friends...who knows what could happen?