Reviews etiology and prevention literatures, exploring relationships between problem and positive youth behaviors, commonalities among predictors, and implications for prevention. Risky/unhealthy/antisocial behaviors, poor mental health, and poor academic achievement are highly prevalent, posing critical dilemmas for adults. All behaviors are highly correlated with, and predict, each other; have similar risk and protective factors; and strongly influence success and happiness. Examples of successful programs are included. (Contains references.) (SM)