Newswise — Half of all cases of mental illness start before age 14 and three-fourths start before age 24, underscoring the need for better early detection and treatment, says Dr. Graham Emslie, professor of psychiatry at UT Southwestern Medical Center.

"If your child describes feelings of being anxious, worried or depressed, and/or is having trouble performing at the same level as before in more than one of three key areas " at school, at home or with friends " then it could indicate it's more than a developmental phase he or she is going through," Dr. Emslie says. "Another concern is a child's free time. Does your child have interests, hobbies and activities that excite him and which he likes to pursue? Kids who are functioning well have long lists of these."

If you believe your child is acting out of character, Dr. Emslie suggests a visit to your primary care doctor, a psychiatrist or a psychologist for possible evaluation.