What I Learned with My Psychology Degree and Personal Experience Depression can take many forms. Most people experience periods at some points in their lives. The tribulations of life in losing health, security, friendships, and loved ones would not make any person happy. When your feelings become a problem interfering with everyday life, clinical depression is diagnosed if the time period is longer than two weeks. When a person feels as though he or she does not enjoy the activities they once did and are sad more often than happy, that person needs to be checked for clinical depression.