LAS VEGAS – The overlap of ADHD, conduct disorder, substance use disorder, and criminality likely reflect related underlying mechanisms, which may elucidate different developmental pathways of offending.
“Early interventions are key,” Praveen R. Kambam, MD, said at an annual psychopharmacology update held by the Nevada Psychiatric Association.
According to Dr. Kambam, a clinical and forensic psychiatrist at the University of California, Los Angeles, ADHD is overrepresented in correctional settings worldwide, especially the hyperactive-impulsive subtype. “In juvenile settings, ADHD rates are 3-4 times higher than rates in the general population,” he said. “If you combine juvenile and adult prison populations worldwide, the rates are about 2-5 times higher than the general population.”
The risks are increased for comorbid oppositional defiant disorder (ODD) and conduct disorder. In fact, ADHD and conduct disorder co-occur in about 50% of cases. In girls, the prevalence rate of conduct disorder is steady at 0.8% around age 5 years and increases to 2.8% around age 15 years, while in boys, conduct disorder is steady at 2.1% around age 5 years and rises to 5.5% at age 15 years.
According to a literature review of 18 prospective studies, 13 retrospective studies, and four reviews, individuals with ADHD plus or minus conduct disorder had an increased the risk of antisocial personality disorder, and those with ADHD plus conduct disorder had an increased risk of criminality (J Atten Disord. 2016;20:815-24). “So it’s a subtle difference, where antisocial personality disorder and criminality are slightly different,” Dr. Kambam said. “It could be that the diagnostic criteria are catching the same thing. However, the added [conduct disorder] suggests that there may be subpopulations that are vulnerable.”
He went on to note that individuals with ADHD and delinquency tend to have more learning problems, poor academic achievement, peer relationship problems, and risk of social rejection, while individuals with oppositional defiant disorder and delinquency tend to have peer relationship problems, a negative parent-child relationship, and increased risk of developing conduct disorder.
ADHD is associated with alcohol and drug use in adulthood and nicotine use in adolescence. “Comorbidity between ADHD and ODD/[conduct disorder] is robustly related to substance outcomes,” Dr. Kambam said. “However, both initiation and continuation of substance use disorder are more likely when ADHD symptoms are present, even when controlling for ODD/[conduct disorder]. As for substance use disorder [SUD] and delinquency, the onset of delinquency is more likely in children with onset of SUD by age 11, and SUDs are closely linked with criminality in both juveniles and adults.”
Comorbidity of SUD with conduct disorder and ADHD likely reflects multifactorial mechanisms, he said, such as inherent novelty seeking or school failure leading to association with antisocial peers. Risk factors for chronic offending include early onset of criminal behaviors, ADHD plus conduct disorder, and ODD. ADHD has an independent yet weaker relationship with antisocial behaviors as well, while ADHD, conduct disorder, and SUD are independently associated with increased recidivism.
Environmental factors for chronic offending include the home environment, peer response, parenting skills, and in utero exposures and perinatal complications. “Whether ADHD develops into more severe conduct problems depends considerably on exposure to potentiating environmental factors,” Dr. Kambam said. “The converse is also true: Low-risk environments promote desistance from this pathway in impulsive boys.” He added that the chronic offenders/criminality pathway likely stems from underlying mechanisms, such as impulsivity, low self-control, and executive dysfunction.
If left untreated, ADHD is associated with poor academic and employment outcomes, SUDs, depression, bipolar disorder, suicide attempts, vehicular accidents, and use of mental health services. “The economic costs are estimated to be $42.5 billion annually, so it has a large impact,” he said.
Limited evidence exists to support pharmacological treatments for conduct disorder, although stimulants/alpha-agonists, antipsychotics, lithium, and mood stabilizers may offer some benefit for target symptoms. “Most of the treatment data center around multisystemic therapy, including behavioral modification/parent management training, and functional family training,” Dr. Kambam said. “Treating disruptive behavior disorders and SUDs are
likely to reduce criminality and recidivism, particularly if started early. There are many beneficial economic impacts. Think about the cost of having youth detained in the criminal justice systems. In Los Angeles County, that cost is about $230,000 per year per kid. That money can probably be better spent somewhere else.”