It is very difficult to be happy when you are sleep deprived. People who are depressed often report feeling sleepy throughout the day. This can result in feeling detached and not able to enjoy life to the fullest. A vast majority of people who suffer from depression also have insomnia. Some believe that this is a vicious cycle where one issue feeds into the other. So, if you feel depressed, give yourself a day to rest and sleep, and try to get into a good sleep schedule. For some people, this will not be enough to completely cure the problem, but it will help tremendously.