Children diagnosed with attention deficit/hyperactivity disorder (ADHD) at ages 4 to 6 are more likely to suffer from depression as adolescents than those who did not have ADHD at that age, according to a long-term study published in the October issue of the Archives of General Psychiatry.
Although it was an uncommon occurrence, the children with ADHD also were somewhat more likely to think about or attempt suicide as adolescents.
"This study is important in demonstrating that, even during early childhood, ADHD in is seldom transient or unimportant," said study director Benjamin Lahey, a professor of health studies and psychiatry at the University of Chicago. "It reinforces our belief that parents of young children with ADHD should pay close attention to their child's behavior and its consequences and seek treatment to prevent possible long-term problems."
Children with ADHD have trouble paying attention and controlling impulsive behaviors and are often overly active. This can cause poor performance in school, difficulties in social situations, and a loss of confidence and self-esteem. The Centers for Disease Control and Prevention estimate that about 4.4 million children, including about four percent of those aged 4 to 6, have ADHD.
Earlier studies of the long-term connections between ADHD, depression and suicidal thoughts produced mixed results. This study benefited from a more comprehensive assessment of depression over a decade, a focus on specific child and family factors that predict which children are most at risk, and consideration of other factors associated with suicidal ideas.
The study, performed by researchers at the University of Chicago and the University of Pittsburgh, followed 123 children diagnosed with ADHD at age 4 to 6 for up to 14 years, until they reached ages 18 to 20. It compared them with 119 children from similar neighborhoods and schools, matched for age, sex and ethnicity. The children were assessed annually in study years 1 through 4, 6 through 9 and 12 through 14.
The researchers found that 18 percent of children diagnosed early with ADHD suffered from depression as adolescents, about 10 times the rate among those without ADHD. Children with early ADHD were five times as likely to have considered suicide at least once, and twice as likely to have made an attempt.
"Suicide attempts were relatively rare, even in the study group," cautioned Lahey. "Parents should keep in mind that more than 80 percent of the children with ADHD did not attempt suicide, and no one in this study committed suicide."
Although the subtypes of ADHD - based on whether they had attention deficit or hyperactivity or both - predict subsequent depression and suicidal thoughts, distinct forms of the disease at age 4 to 6 were moderately predictive for specific problems later on. Children with inattention or combined subtype were at greater risk for depression. Those with combined type or hyperactivity were at greater risk for suicidal thoughts.
Far more boys than girls suffer from ADHD, but being female increased the risk of depression. Children whose mothers suffered from depression were also at increased risk.
Children with more complicated ADHD were most at risk, the authors conclude. "Greater numbers of depression, anxiety, oppositional defiant disorder and conduct disorder symptoms at ages 4 to 6 among children with ADHD robustly predicted risk for depression during adolescence. Children with uncomplicated ADHD with few concurrent symptoms of other disorders were at low risk for depression, but children with many concurrent symptoms were at very high risk."
The National Institutes of Health funded this study Additional authors include Andrea Chronis-Tuscano of the University of Maryland; Brooke Molina of the University of Pittsburgh; William Pelham of Florida International University; Brooks Applegate of Western Michigan University; and Allison Dahlke and Meghan Overmyer of the University of Chicago.