The question of whether moods constitute bad habits is an interesting one. Many mood disorders have been identified. These and other psychological problems are seen by some as strictly bad habits.

In fact, it has been shown that continuing to dwell in your present mood perpetuates it. When you decide to pretend you are happy, studies show that you may actually improve your mood in time. This is not a hard and fast rule, but there is some indication that people do have some control over their moods.