Feeling sad, mad, critical or otherwise awful? Surprise: negative emotions are essential for mental health. In fact, anger and sadness are an important part of life, and new research shows that experiencing and accepting such emotions are vital to our mental health. Attempting to suppress thoughts can backfire and even diminish our sense of contentment. "Acknowledging the complexity of life may be an especially fruitful path to psychological well-being," says psychologist Jonathan M. Adler of the Franklin W. Olin College of Engineering.