Subclinical depression is a condition in which a person has clinically relevant depressive symptoms, but does not meet criteria for a depressive disorder. In this presentation, the different operationalizations of subthreshold depression will be presented, and we will focus on the importance from a clinical point of view, as well as from a public health public point of view. Subthreshold depression has important consequences for the quality of life, but not as much as major depression. It also results in huge economic costs on the individual level, but again less than the costs associated with major depression. Because subthreshold depression is more prevalent, the total costs of subthreshold depression on the population level are, however, comparable to those of major depression. It is also clear that subjects with subthreshold depression have an increased risk of developing a major depression. How large that chance is depends on several factors, including the definition of subthreshold depression. Finally, the results of a meta-analysis will be presented in which the effects of psychological treatments of subthreshold depression are examined. This meta-analysis shows that psychological treatments can be treated effectively, and there is a trend indicating that these interventions can prevent the onset of major depression.