ICD-10 Diagnostic Criteria for Attention-Deficit Hyperactivity Disorders (F90)
Attention-deficit hyperactivity disorders are behavioral disorders characterized by a marked pattern of inattention and/or hyperactivity-impulsivity that is inconsistent with developmental level and clearly interferes with functioning in at least two settings (e.g. at home and at school). At least some of the symptoms must be present before the age of 7 years. Although most individuals have symptoms of both inattention and hyperactivity-impulsivity, one or the other pattern may be predominant. Symptoms often attenuate during late adolescence although a minority experience the full complement of symptoms into mid-adulthood. The disorder is more frequent in males than females. The ICD-10 lists five separate subcategories (see below).
F90 Attention-deficit Hyperactivity Disorders
F90.0 Attention-deficit hyperactivity disorder, predominantly inattentive type;
F90.1 Attention-deficit hyperactivity disorder, predominantly hyperactive type;
F90.2 Attention-deficit hyperactivity disorder, combined type;
F90.8 Attention-deficit hyperactivity disorder, other type;
F90.9 Attention-deficit hyperactivity disorder, unspecified type;
Reproduced with permission from ICD-10 Diagnostic Criteria for Attention-deficit hyperactivity disorders (World Health Organization, Geneva, Switzerland, 2003)
Attention-deficit/hyperactivity disorder (ADHD) is the most common emotional, cognitive, and behavioral disorder treated in youth. It is a major clinical and public health problem because of its associated morbidity and disability in children, adolescents, and adults. Data from cross-sectional, retrospective, and follow-up studies indicate that youth with ADHD are at risk for developing other psychiatric difficulties in childhood, adolescence, and adulthood, including delinquency as well as mood, anxiety, and substance-use disorders.
Early definitions, such as the Hyperkinetic Reaction of Childhood in DSM-II, placed the greatest emphasis on motoric hyperactivity and overt impulsivity as hallmarks of the disorder. The DSM-III represented a paradigm shift, as it began to emphasize inattention as a significant component of the disorder. DSM-IV defined three subtypes of ADHD: predominantly inattentive, predominantly hyperactive–impulsive, and a combined subtype. In DSM-5 the same 18 symptoms are used; however, there are six notable changes. First, descriptors are included to aid diagnosis at later ages; second, the cross-situational requirement has been increased to several symptoms in each setting; third, the age of onset criterion has been advanced to several symptoms before age 12; fourth, prior subtypes are now termed presentation specifiers; fifth, the existence of autism spectrum disorder does not preclude an ADHD diagnosis; and sixth, the minimum number of symptoms for adults has been reduced to five symptoms for either presentation specifier. The current ICD-10 criteria (see above) largely mirror the DSM-IV criteria.
A recent meta-analysis of 86 worldwide studies of children and adolescents determined an overall prevalence of 5.9–7.1%, depending on diagnostic procedure. There were no significant prevalence differences between countries after controlling for differences in diagnostic algorithms. Although ADHD was previously thought to remit largely in adolescence, a growing literature supports the persistence of the disorder and associated impairment into adulthood in a majority of cases.