The study differentiates among the effects of social support growth, decay, and staticity on well being. Support growth suggests that a person is forging close friendships or that existing social influences are becoming more supportive over time. Support decay could mean that a person is feeling increasingly detached from friends, or is feeling neglected by the family. Social support staticity is when a person might be content with his or her social situation or is reluctant or unable to change it, or that an individual lacks the opportunity or ability to change the situation. The main hypothesis is that support decay is a more powerful force than support growth. The Add Health study was used because it was multidimensional, contained several components, and focused on many health-related behaviors of adolescents. Results show that the effects of support change are more important than even the cumulative effects of experiencing relatively high or relatively low amounts of support. In addition to the importance of adolescents receiving social support at any given time, it is important that they perceive stable or increasing amounts of support over time. Adolescents that experience decay of parental or friendship support experience higher levels of depression on average than those that experience static or increasing amounts of support over time. The effect of social support decay is greater in magnitude than the effects of support staticity or growth. It is easier to make an adolescent more depressed by denying him or her the amount of support (s)he is used to than it is to alleviate an adolescent’s depression by intervening with more support. A decrease in parental support over time appears to be an especially affective, traumatic experience for adolescents. It is more useful to embrace proactive, rather than reactive, approaches to mental health. 6 tables, 11 notes, 45 references