July 29, 2010 — Teenagers with attention-deficit/hyperactivity disorder (ADHD) are more likely to drop out of high school or delay high school graduation than their counterparts with more "serious" mental health conditions, new national data suggest.
Investigators at the UC Davis MIND Institute in Sacramento, California, found that compared with teens with no psychiatric disorders, those with the combined type of ADHD were more than twice as likely to drop out or finish high school on time. In addition, ADHD trumped high school incompletion rates for other mental health disorders, including mania, mood disorders, and panic disorders.
Conduct disorder and smoking were also significantly associated with an increased risk of failing to complete high school on time, but ADHD still led the pack.
"Most people think that the student who is acting out, who is lying and stealing, is most likely to drop out of school. But we found that students with the combined type of ADHD — the most common type — have a higher likelihood of dropping out than student with disciplinary problems," study investigator Julie Schweitzer, PhD, said in a statement.
"This study shows that ADHD is a serious disorder that affects a child's ability to be successful in school and subsequently in a way that can limit success in life," she added.
The study was published online July 16 in the Journal of Psychiatric Research.
According to the investigators, one-third of youth in the United State do not complete high school on time. "Sorting out which disorders are most likely to affect educational progress is important because different disorders might affect educational outcomes through distinct causal pathways and might require different approaches to (and timing of) interventions," the study authors write.
For the study the investigators examined the joint, predictive effects of childhood- and adolescent-onset psychiatric and substance use disorders on failure to graduate high school on time using data from the 2001 and 2002 National Epidemiological Survey of Alcohol and Related Conditions.
The final study cohort included 29,662 respondents 18 years and older who were interviewed about the age of onset of psychiatric diagnoses, substance use, and high school graduation.
Of the total sample, 5310 (16.9%) did not complete high school on time. Of those with no history of any psychiatric disorder before the age of 18 years, 15.2% did not graduate on time. In comparison, rates for those with ADHD combined type were 33.2%.
At 28.6% the highest dropout rates were found in those whose conditions were diagnosed in childhood or adolescence with either the combined or inattentive type of ADHD. Those with mania, a mood disorder, and panic disorder dropped out at 26.6% and 24.9% respectively.
After adjusting for co-occurring disorders, significant associations with failure to graduate on time remained only for conduct disorder and the 3 ADHD subtypes (inattentive, hyperactive-impulsive, and combined).
However, more predictive of dropping out than all other mental health disorders except ADHD and conduct disorder was tobacco use. The study showed that 29.1% of those who used tobacco failed to complete high school on time.
In comparison, 20.5% of those who used alcohol and 24.6% of those who used drugs dropped out.
"This study suggests that focusing on a relatively narrow and hopefully more manageable range of mental-health conditions may have a consequential impact of improving school performance in secondary education," study investigator Joshua Breslau, PhD, said in a statement.
The study authors have disclosed no relevant financial relationships.
J Psychiatr Res. Published online July 16, 2010.