TUESDAY, June 7 (HealthDay News) -- Mental health problems are the leading cause of disability among children, teens and young adults worldwide, according to a new study.

Researchers who analyzed global data collected in 2004 found that neuropsychiatric disorders -- including depression, schizophrenia, bipolar disorder and alcohol use -- accounted for 45 percent of the disease burden among those 10 to 24 years old.

The next two most common causes of disability among young people were accidental injuries, most often caused by traffic accidents, at 12 percent, and infectious and parasitic diseases at 10 percent.

The researchers also found that important risk factors among young people that affect their health later in life include unsafe sex, alcohol use, iron deficiency and lack of birth control.

"The disease burden arising in early adolescence from major risk factors is low," the researchers wrote. "However, rates rise sharply in late adolescence and early adulthood for both alcohol and unsafe sex. For other risk factors that commonly start in adolescence, such as tobacco use, low physical activity, high blood pressure, and overweight and obesity, their contribution to disease becomes apparent only in mid- to-late adulthood," according to Fiona M. Gore, of the department of health statistics and informatics at the World Health Organization in Geneva, Switzerland, and colleagues.

"Our risk factor data suggest that preventive strategies should adopt a life-course approach whereby the focus on the adolescent and young-adult years is prominent," the authors concluded in the report published online June 7 in The Lancet.

People aged 10 to 24, numbering more than 1.8 billion, represent 27 percent of the world's population, the report noted.

More information

The U.S. National Institute of Mental Health has more about child and teen mental health.