Seeing the glass as half full could have health benefits beyond helping you to be positive and hopeful Australian researchers have found it can prevent depression.
A study of more than 5600 Australian adolescents, conducted by the Royal Children's Hospital in Melbourne, found that positive thinking helped to reduce the likelihood of depression, anxiety, substance abuse and anti-social behaviour.
The research team conducted a three-wave longitudinal study of teenagers aged from 12 to 14 from three Australian states, assessing their way of thinking, emotional and social behaviours each year from 2003 to 2005.
Teenagers who ranked in the highest "optimism quartile" were 50 percent less likely to suffer from depression compared with those who ranked in the lowest quartile, the researchers wrote in the medical journal Pediatrics.
Having an optimistic outlook on life also helped to reduce the chances of teenagers developing substance abuse issues and anti-social behaviours.
Positive thinking had similar protective benefits for both boys and girls, but researchers did find more girls in every level of self-reported optimism suffered from symptoms of depression.
"Promoting optimism along with other aspects of psychological and emotional style has a role in mental health promotion that is likely to be enhanced if an intervention also addresses risk and protective factors in an adolescent's social context," the research team led by Dr George C Patton from the Royal Children's Hospital wrote.
But how do you teach your children to be optimistic? Is optimism nature or nurture? Dr Leslie Walker from Seattle Children's Hospital told Today.com that children are born with their personality traits, but that an optimistic outlook can be created.
Dr Walker said the best way for parents to help their children grow up as optimists is to lead by example.
"Patterning after their parents is how kids figure out how to live," Dr Walker said. "If parents are optimistic about what's going in their lives, you can expect the kids to follow."
Dr Walker herself a mother of an 18-year-old daughter recommended parents should always listen to what their children are saying and let them speak without fear of being judged.
She said it was important not to attach negative labels to children such as "shy" or "naughty" and said children will often live up or down to their parents' expectations.
The doctor also said parents should not dismiss their kids' concerns or complaints, that teenagers want to be taken seriously and parents need to acknowledge their reality. If your child says "I hate school", don't dismiss this with an "it'll be okay"-type comment, Dr Walker said, instead help children to come up with examples of what they do like about school.
Finally, Dr Walker suggested parents should lead by example show your kids there is a silver lining to every dark cloud.
"Optimism and hope are very close and it's something we as parents don't spend a lot of time looking at, and we need to," Dr Walker said. "It's key to why a kid gets up in the morning and tries again."
For more information about teenagers and depression, go to The Lowdown