Being unhappy could age you faster than smoking. In a new study published in the journal Aging, researchers looked at the impact of mental health on our biological clocks. They found that psychological factors, such as feeling unhappy or lonely, added over 1.5 years to a person’s biological age. This aging effect of being unhappy or lonely exceeded that of gender, relationship status or even smoking. Maintaining optimal mental health might be just as important as ideal physical health when it comes to longevity.