Few prospective studies have examined the relationship between social support and psychological distress and depressive symptoms in adolescents. The aims of this study were to test whether social support is protective against psychological distress and depressive symptoms in an ethnically diverse population of adolescents and whether differences in support are reflected by ethnic differences in psychological distress and depressive symptoms. Based on a longitudinal survey of 821 adolescents, this study found low levels of social support from family members was prospectively associated with depressive symptoms (OR = 2.25, 95% CI 1.43-3.54). Compared with White UK pupils, Black pupils were less likely to display psychological distress (OR = 0.21, 95% CI 0.09-0.51). However, social support did not explain the ethnic variations in psychological distress. Family environment may be a more consistent source of support compared with support from peers. The lower risk of psychological distress among Black pupils compared to White pupils requires further investigation. (Contains 3 tables and 1 figure.)