BERLIN – Concerns that the liberalized criteria for adult attention-deficit/hyperactivity disorder adopted in the DSM-5 would greatly inflate the disorder’s prevalence appear to have been misplaced.
“The adult ADHD prevalence under DSM-5 is in the same range as ADHD not otherwise specified in DSM-IV. There’s no dramatic increase,” Dr. Josep Antoni Ramos-Quiroga said at the annual congress of the European College of Neuropsychopharmacology.
Bruce Jancin/Frontline Medical News
Dr. Josep Antoni Ramos-Quiroga
The DSM-IV and DSM-5 criteria differ in two ways. One difference is that the required age of onset for ADHD symptoms has changed from prior to age 7 years to prior to age 12 years. The other change is that the minimum number of symptoms of attention and/or hyperactivity/impulsivity required for the diagnosis has decreased from 6 to 5 out of a possible 9.
These changes came under fire from some quarters during the lengthy DSM-5 development process, but two recent large studies suggest that the clinical impact of the revised criteria is minimal, according to Dr. Ramos-Quiroga, coordinator of the ADHD program at Vall d’Hebron University Hospital in Barcelona.
He was a coinvestigator in the ADPSYC study, an observational study in which 1,986 nonpsychotic psychiatric outpatients in eight European countries were evaluated for adult ADHD. As he and his colleagues predicted, the prevalence of the disorder proved much higher than the consensus estimate of 2.5% in the general adult population. Indeed, using the Diagnostic Interview for ADHD in Adults (DIVA) based upon the DSM-IV criteria, 15.8% of the psychiatric patients in a variety of outpatient settings had adult ADHD. When the investigators applied the DSM-5 criteria, the prevalence rose to 17.4%.
Dr. Ramos-Quiroga also was a coinvestigator in the International ADHD in Substance Use Disorders Prevalence study (IASP), a cross-sectional study involving 3,558 treatment-seeking substance-use disorder (SUD) patients in the United States, Australia, and eight European countries. The prevalence of adult ADHD by DSM-IV criteria varied substantially from country to country but averaged 13.9% overall. By DSM-5 criteria, the prevalence was only slightly higher (Drug Alcohol Depend. 2014;134:158-66).
It has been known for at least 2 decades that adults with SUD have an increased prevalence of comorbid ADHD, compared with the general population and that these dual-diagnosis patients have a more severe course of substance use, the psychiatrist noted.
In another report from the IASP study, Dr. Ramos-Quiroga and his colleagues found that SUD patients with adult ADHD had a 7-fold greater rate of borderline personality disorder, a 2.8-fold increase in antisocial personality disorder, and a 4.3-fold greater prevalence of hypomanic episodes, compared with SUD patients without ADHD. Also, among the subset of patients with alcohol as their primary substance of abuse, those with adult ADHD had a 4.3-fold greater prevalence of major depression than those without ADHD (Addiction 2014;109:262-72).
The ADPSYC study was supported by Eli Lilly. Dr. Ramos-Quiroga reported acting as a consultant to and serving on the speakers bureau for that pharmaceutical company and a handful of others. The IASP study was supported by the International Collaboration on ADHD and Substance Abuse.