F. Xavier Castellanos, M.D.
Attention-Deficit/Hyperactivity Disorder (ADHD)
Over the past six months, discussions and deliberations have been held by the ADHD work group subcommittee:
1. Secondary data analyses are being performed to inform the decision as to whether to retain all 18 A criteria as is or whether redundant items can be deleted without altering the fundamental structure of the remaining items and their psychometric properties.
2. Decisions regarding cutpoints for meeting diagnostic criteria in childhood will be based on secondary data analyses of extensive data sets that are ongoing. Similarly, the option of applying differential weights to some criteria remains open, pending secondary analyses and deliberations.
3. DSM-IV subtypes of predominantly hyperactive-impulsive and predominantly inattentive ADHD have not been supported by the empirical data; instead the evidence suggests that the classification of subtypes in ADHD is strongly influenced by method variance (e.g., by differences in informants, instruments, or in the algorithms used for combining information across informants). The consensus is that the existing subtypology is not useful.
a. One question being examined is whether to differentiate ADD from ADHD. ADD would only apply in the near or complete absence of lifetime expression of hyperactive/impulsive symptoms; individuals with appreciable hyperactivity symptoms in childhood would retain the diagnosis of ADHD even if the hyperactivity/impulsivity symptoms were to be in partial or full remission. This is not a simple reversion to DSM-III ADD, since that construct permitted/required symptoms of impulsivity.
b. Alternatively, there could be a single disorder of ADHD comprising the popular conceptions of ADD and ADHD.
c. The decision regarding these two options will turn on our judgement regarding the sufficiency of evidence of clinically meaningful distinctions between non-hyperactive/impulsive ADD and ADHD; also relevant will be estimates of the prevalence of the putative ADD construct.
d. Data being compiled by Work Group members bearing on these issues will shortly be available to provide a stronger basis for these decisions.
4. Regardless of the decision with respect to options #3a and 3b, the three cardinal dimensions of the disorder (hyperactivity, inattention, impulsivity) should be considered as domains that could be assessed dimensionally.
a. These three dimensions could also be applicable across other diagnostic categories that are commonly comorbid with DSM-IV-TR ADHD (e.g., Oppositional Defiant Disorder, Conduct Disorder, Learning Disorders; Tourette’s Disorder; Autism Spectrum Disorders). It is not clear whether it would be advantageous to have these three dimensions apply to all axis I disorders. An alternative would be to encourage such use in diagnoses that exhibit appreciable comorbidity as currently defined.
b. There is overwhelming evidence that the DSM-IV-TR A criteria yield two dimensions (inattention and hyperactivity/impulsivity) for children. One problem is that DSM-IV-TR A criteria give short shrift to impulsivity. Arguably, children are also provided fewer opportunities to make impulsive decisions with serious consequences (e.g., motor vehicle accidents, high risk sexual behaviors, substance abuse, etc.).
c. More recent data provide support for a three-dimension factor structure for adults with ADHD that includes impulsivity/impulsive decision-making.
5. There is compelling evidence for the lifespan continuity of ADHD as a disorder that begins and manifests initially in childhood and that can continue to be associated with enduring impairment. However there is also consensus that the DSM-IV-TR A criteria are inadequate for adults and older adolescents. Thus, the A criteria for adults with ADHD, and probably for adolescents with ADHD, will need to be changed, and those changes will need to be tested in field trials. The Childhood and Adolescent Disorders Work Group has suggested, among several alternatives, that DSM-5 should contain sections that demonstrate how a particular criterion may manifest at different ages while still reflecting the same underlying construct. These would be called “age-related manifestations.” The ADHD workgroup will consider this as a means of maximizing the continuity of symptom descriptions across the lifespan.
a. Despite the importance of contextualizing existing criteria for age/developmental factors, impulsive decision-making is inadequately covered in DSM-IV-TR. Such impulsive decision-making appears to be associated with much of the disability associated with the diagnosis beyond childhood. [Impulsive symptoms are also inadequately assessed for children – the loss of the earlier item of ‘engages in dangerous activities’ or items such as ‘acts without thinking’ is of concern.] Additionally, since the wording of the DSM-IV-TR criteria were designed with children in mind, several of the criteria apply poorly or not at all to adults and older adolescents. An alternative set of criteria is under consideration by the workgroup.
6. The age-of-onset (B) criterion that some symptoms causing impairment be present before age 7 years is being examined. It is important that the age-of-onset criterion be set to an age prior to the ages of greatest risk of drug abuse, mood disorders, and psychotic disorders.
7. There is strong support to eliminate the hierarchical exclusion that “the symptoms do not occur exclusively during the course of a Pervasive Developmental Disorder.” We anticipate that having dimensional measures of hyperactivity, impulsivity and inattention will facilitate assessing and communicating the extent to which such difficulties represent an additional burden in comorbid conditions (in which full criteria are met for both disorders) as well as subthreshold types of comorbidity.
8. The work group will also be discussing the requirement that symptoms be present for at least six months, as opposed to 12 months.
9. Although the possibility of adopting Hyperkinetic Conduct Disorder as a way of ‘carving’ off ADD from ADHD+CD was examined, the current thinking is to maintain the disorders as independent but associated diagnoses.
10. The work group has conducted or commissioned a number of literature reviews and secondary analyses. These will be compiled to be made readily available to all work group members and liaisons.