Conduct Disorder and ADHD: Predictors for Substance Abuse

Summary

Attention deficit hyperactivity disorder (ADHD) and associated comorbidities are known to be risk factors for substance abuse in adolescence and young adulthood, but few studies have examined the early childhood risk factors that may predispose to this behavior. In a 10-year follow-up of children with ADHD, the occurrence of substance use disorder was increased compared with controls, especially among ADHD youth with early conduct disorder.

  • Personality Disorders
  • Substance-Related Disorders Clinical Trials
  • Child & Adolescent Neurodevelopmental Disorders

ADHD and associated comorbidities are known to be risk factors for substance abuse in adolescence and young adulthood, but few studies have examined the early childhood risk factors that may predispose to this behavior. In a 10-year follow-up of children with attention deficit hyperactivity disorder (ADHD), the occurrence of substance use disorder (SUD) was increased compared with controls, especially among ADHD youth with early conduct disorder, according to a study from by Timothy E. Wilens, MD, Massachusetts General Hospital and Harvard Medical School, Boston, MA.

“We hypothesized that early delinquency and academic or cognitive dysfunction will predict later SUD in two cohorts of ADHD children, followed for an average of 10 years. We examined early predictors for later SUD,” said Dr. Wilens.

The study compared 257 youths with ADHD to 225 youths without ADHD. All subjects were aged 6 to 17 years at baseline and were followed for approximately 10 years. Study subjects were assessed in a blinded manner using DSM-IV Schedule for Affective Disorders and Schizophrenia for School-Aged Children, epidemiological edition (KSADS-E), or Structured Clinical Interview for DSM Disorders (SCID), cognitive measures, Family and Environmental Scale (FES), and Social Adjustment Inventory for Children and Adolescents (SAICA) rating scales. Psychopathology and SUD were determined by structured interview.

At baseline, the subjects had a mean age of 11 years, and 50% of the study population was male. Most were Caucasian from middle-class families. The subjects and controls were similar except that ADHD subjects were significantly more likely to have a parental history of alcohol use disorders (p<0.001) and drug use disorders (p=0.003).

Investigators found that children with ADHD were 1.5 times more likely to develop a SUD compared with controls. Within ADHD, comorbid oppositional defiant disorder and conduct disorder were significant predictors of any SUD, after adjusting for gender (hazard ratio [HR], 2.31; p<0.001) and parental history of SUD (HR, 3.0; p<0.001).

Within the population of ADHD youths who developed drug use disorders, comorbid major depressive disorder was a further significant predictor, essentially doubling the risk (p=0.006). Analysis showed that boys who received extra help in school were approximately half as likely to develop a SUD (p=0.02).

“In general, gender did not predict risk for SUD, and we found no significant associations between baseline cognitive or academic dysfunction and later SUD in our ADHD youth,” Dr. Wilens said. “No significant results were found for social or family environment factors, cognitive factors, or any school functioning factors.”

“Dr. Wilens and colleagues showed that there are children with ADHD that are at risk for substance abuse, but most of them have a diagnosis of conduct disorder, which translates into juvenile delinquency later. Many ADHD children want to be good. For the child with conduct disorder, ‘being good’ is not a priority. This work says that ADHD plus conduct disorder equals a very serious problem,” commented R. Scott Benson, MD, APA Council on Communications.

The study suggests that the vast majority of ADHD children will not abuse drugs later, but if a child has more severe, oppositional behavior, that child may be at risk of developing serious substance abuse issues. The challenge for psychiatrists is to find ways to treat these comorbidities.

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