Surly youths are more likely to suffer ill health in later life, claims a new study.
However, adolescents with a sunny outlook on life may have better health in their adult years.
According to the study, teenagers are known for their angst-ridden ways, but those who remain happy and positive during the tumultuous teenage years report better general health when they are adults.
The researchers also found that teens with high positive well-being had a reduced risk of engaging in unhealthy behaviour such as smoking, binge drinking, using drugs and eating unhealthy foods.
The study is one of the first to focus on the effect positive psychological characteristics in adolescence can have on long-term health.
"Our study shows that promoting and nurturing positive well-being during the teenage years may be a promising way to improve long-term health," the Daily Mail quoted Study author Lindsay Hoyt, at Northwestern University, as saying.
The results come from the analysis of data collected from 10,147 young people as part of the National Longitudinal Study of Adolescent Health, known as Add Health.
Co-author Emma Adam, an associate professor of education and social policy, said: "Our results show that positive well-being during adolescence is significantly associated with reporting excellent health in young adulthood.
"Positive well-being is more than just the absence of depression; the influence of a teenager's positive well-being on long-term good health is present even after accounting for the negative health effects of experiencing depressive symptoms in adolescence," added Adam.
The study has been published in the Journal of Adolescent Health.