Often, when we think of patients at Children's Hospital, we mentally picture newborns or toddlers. But Children's cares for patients up to the age of 19, and many adolescent patients have trouble admitting that they're sick. The phenomenon is called "denial," and Children's has a special way of dealing with it. My associate Charlise Lyles filed this report:

"Junkies on 14th Street buy needles from a 17-year-old diabetic. Doctors at Children's Hospital provided the teenager with the syringes so he could take insulin injections. But because he doesn't want to admit he's sick, the teenager sells them.

"A 16-year-old epileptic stops taking the phenobarbitol his doctor prescribed to prevent violent seizures that could cause him to swallow his tongue.

"Another 16-year-old suffering from severe acne and osteomyelitis (a painful bone infection) stays in bed all day--refusing to take medication to soothe the stinging sores on his face, back and arms.

"These adolescent patients at Children's Hospital have three very different diseases, but they share a common psychological reaction to chronic illness: denial.

"According to Dr. Dan Davidow, a pediatrician sub-specializing in adolescent medicine at the Children's adolescent clinic, 90 percent of chronically ill adolescents exhibit some form of denial during their illnesses. About 25 percent refuse to believe their survival is dependent on medication, and refuse to take it on a regular basis.

"But Children's has attacked the problem of denial by arranging for adolescent patients to see the same set of doctors every time they come to the hospital.

"By dealing with the same doctor, nurse and pediatrician each time he comes to the hospital, the adolescent is more likely to talk honestly about his feelings toward the illness. In turn, the medical team is better aware of the patient's personality and better able to detect changes in attitude and behavior before failure to take medicine produces a crisis.

" 'Child life' and social workers are also part of the team.

"To change 'denial' attitudes, social worker Dennis Howard encourages peer pressure in his outpatient diabetic support group. Surrounded by other chronically ill adolescents, patients can express anger and frustrations they may be afraid to show around parents and doctors.

" 'Nobody in the world can make a teenager take medicine when he doesn't want to believe he's sick,' Howard said. But in attacking the problem of denial through consistent care and peer-group counseling, the dedicated team at Children's seems to be having more success than most."