Epistemological loneliness refers to the isolation adolescents may experience as the result of cognitive relativism, ushered in by the emergence of formal operational thought. To examine the relationship between cognitive relativity, epistemological loneliness, and depression in adolescence, 108 adolescents (29 seventh graders, 29 ninth graders, 21 high school juniors, and 29 college freshmen) completed a battery of tests. The battery included the Defining Issues Test, the UCLA Loneliness Scale, the Adolescent Depression Scale, and the Epistemological Relativity Scale. An analysis of the results showed a significant relationship between cognitive relativism and clinical loneliness and depression. Contrary to expectations, no relationship was found between relativism and advanced social cognitive development, as measured by moral reasoning. The findings support the notion that cognitive relativity has affective consequences. (BL)