When you are depressed life is hard enough, but being depressed takes our energy and leaves a foggy mind. This makes being social very hard and we have to try hard to make friends, more than other people. Also some of us stopped trusting people for one reason or another and this contributes to making friends hard for us. Try to do something nice for someone and this might lead to a new friend. Forget about yourself and do nice things for others and they will want you to be their friend. Good Luck