Substance abuse, learning disabilities, physical and sexual assault and criminal activity all affect an adolescent's health. But most primary-care physicians devote the majority of their practice to caring for the very young and the very old.

Often they're not up to speed on the issues that play such important roles in a teen's well-being.About 30 primary-care physicians gathered at LDS Hospital Friday to learn more about issues of adolescence. These ranged from an immunizations update to recognizing abused or suicidal teenagers, helping prevent teen pregnancy and coping with HIV in youths. The daylong adolescent health conference was sponsored by Intermountain Health Care and the Association for Utah Community Health.

So many things are interconnected, said 3rd District Juvenile Court Judge Kimberly Hornack during a panel discussion on issues and resources. "We often see kids for abuse and neglect who come into the court system later" for criminal actions.

Children with serious criminal involvement "almost all had abuse and neglect" in their lives, she said.

The judge noted that attention deficit hyperactivity disorder is also common in the youths with whom she deals. And "we find a lot of boys with very serious depression." Girls who get in serious trouble tend to have very low self-esteem. And about 40 percent of them are pregnant or sexually active on a regular basis.

While few of the girls have a learning disability, Hornack said that most of them have been physically or, more commonly, sexually abused.

Her experience has led her to believe there are risk factors: single parent households, not doing well in school, abuse or neglect, a parent or sibling who has been in legal trouble, learning disabilities and more. But she added that some children who become delinquents "don't always fit profiles."

Another piece of the puzzle, said Dr. Michael Crookston, is substance abuse. By their senior year, more than half of the youths have used an illicit drug, according to reputable surveys. That includes alcohol, drugs and tobacco. Alcohol and tobacco are the most common.

Nearly 40 percent of seniors admit to "episodic heavy drinking" and about a quarter used marijuana within the past month at the time of the survey, said Crookston, who is medical director of both Odyssey House's adolescent program and LDS Hospital's Dayspring.

Use of dangerous inhalants is common in middle school, and one-fourth admit to using them. That seems to decrease as teenagers get older.

It's a national problem. According to a Centers for Disease Control survey, 80 percent of adolescents had tried alcohol. In Utah, the number was 41 percent.

For lifelong health, delaying the age at which children experiment with drugs is crucial, he said. The longer they wait, the less apt they are to become dependent on the substance.

Dr. Kathleen M. McElligott, director of the Teen Mother and Child Program at University Hospital, said that one-third of the pregnant teens with whom she deals have reported physical and sexual abuse. Alcohol and drug abuse are common. Between 10 percent and 20 percent have been treated for psychiatric disorders.

The need for career planning and job training is crucial to break the cycle of their lives, McElligott said. And at least half of the teens are not in school when they enter the teen mom program.

That doesn't surprise Eva Jean Pickering, neuro-education director for Specialized Educational Programming Services Inc. She's spent a year working with children who have learning disabilities - and many of those youths have been in programs like Hornack's or Crookston's or McElligott's, she said.

Too many school officials, doctors and others don't recognize the burden a learning disability places on a youth, she said. Yes, they can succeed. But they have to work so much harder and give up a social life. They have to face negative statements every day. And they watch their non-learning-disabled friends cruise through while they slave.

That, in turn, can lead to "self-medicating" with drugs and alcohol. And it interacts with all those other issues, from teen pregnancy to juvenile crime.