You may be surprised how good it feels to talk to such a friend and find out, all over again, how much you have in common. These activities feel good in themselves and they put you in touch with others who may offer some company. You may want to take certain supplements like St. John's Wort that help to fight depression. Often your doctor can switch the medication to something less bothersome. If nothing else, walk - everywhere you can.
Exercise causes the brain to release endorphins that, wonderfully enough, elevate the mood.
Often psychiatrists recommend adding exercise to the treatment of depressed patients, for that very reason. Park the car far away. Go on a hike. It's hard to stay sad when you're helping others. Getting out there and pitching in can help you as much as it helps the people you're helping.