- Summarize and differentiate the various forms of mood disorders, in particular dysthymia, major depressive disorder, and bipolar disorder.
- Explain the genetic and environmental factors that increase the likelihood that a person will develop a mood disorder.
The everyday variations in our feelings of happiness and sadness reflect our mood, which can be defined as the positive or negative feelings that are in the background of our everyday experiences. In most cases we are in a relatively good mood, and this positive mood has some positive consequences—it encourages us to do what needs to be done and to make the most of the situations we are in (Isen, 2003). When we are in a good mood our thought processes open up, and we are more likely to approach others. We are more friendly and helpful to others when we are in a good mood than we are when we are in a bad mood, and we may think more creatively (De Dreu, Baas, & Nijstad, 2008). On the other hand, when we are in a bad mood we are more likely to prefer to be alone rather than interact with others, we focus on the negative things around us, and our creativity suffers.
It is not unusual to feel “down” or “low” at times, particularly after a painful event such as the death of someone close to us, a disappointment at work, or an argument with a partner. We often get depressed when we are tired, and many people report being particularly sad during the winter when the days are shorter. Mood (or affective) disorders are psychological disorders in which the person’s mood negatively influences his or her physical, perceptual, social, and cognitive processes. People who suffer from mood disorders tend to experience more intense—and particularly more intense negative—moods. About 10% of the U.S. population suffers from a mood disorder in a given year.
The most common symptom of mood disorders is negative mood, also known as sadness or depression. Consider the feelings of this person, who was struggling with depression and was diagnosed with major depressive disorder: