ADHD's Dynamic History: The Effects of Continuously Changing Diagnostic Criteria
For over 100 years, the symptoms that constitute ADHD have been continuously refined by the scientific community. Many researchers note that one of the earliest scholarly papers on symptoms consistent with ADHD was written in 1902 by George Still, in which he described a series of children who exhibited impulsivity, inattentiveness and restlessness, and showed intense emotional and behavioral problems. At the time it was commonly thought that lack of inattention and inhibitory control was the primary characteristic of the syndrome. In 1920's "minimal brain damage syndrome" was the term used to characterize children with similar behavioral problems who had survived the epidemic of encephalitis lethargica and the pandemic of influenza from 1919 to 1920. In the 1960's the term "minimal brain dysfunction" was used but both this and "minimal brain damage syndrome" were very unpopular terms in part because of stigma that was associated with them, but also because no specific area of "brain damage" or "brain dysfunction" had been clearly identified.
In the 1960's the major classification systems of the day, the Diagnostic and Statistical Manual of Mental Disorders (DSM-II) and the International Statistical Classification of Diseases and Related Health Problems (ICD-9) had more descriptive titles with emphasis on hyperactivity as the key symptom (ex: hyperactive child syndrome, hyperkinetic syndrome). As more research was conducted there was a general suggestion that hyperactivity was a secondary problem to impulse control and the inability to maintain attention. Therefore, in the DSM-III the condition was renamed "attention-deficit disorder". This disorder was described as consisting of three categories of symptoms: inattention, hyperactivity, and impulsivity. Three subtypes of attention-deficit disorder were also characterized; problems with attention with hyperactivity, without hyperactivity, and a third residual subtype for those who didn't meet full criteria for the other two diagnoses.
In 1987, the revised DSM-III (DSM-III-R) included the diagnosis attention deficit/hyperactivity disorder. This version was significantly different from the previous categorization, in particular in that this description did not include any subgroups. This diagnostic system was created by a committee of experts coming to a consensus. The most recent version of the diagnosis, the one currently in use in the DSM-IV, was defined in part by trials that involved children evaluated with interviews and diagnostic instruments created to test the validity of the different subgroups of ADHD.
What I hope is clear from this discussion is that ADHD is a diagnosis describing a collection of symptoms that have been generally recognized for over 100 years, but the specific requirements for the diagnosis have changed significantly. As recently as 1987 there was a very different set of rules governing the diagnosis of ADHD. It just may be that in the upcoming DSM-V, the rules may change again.
Another point that I hope becomes clear is that the changes in the diagnosis of ADHD make it more difficult to compare the effects of new medications to older ones. When a researcher or physician looks at a study of medication used to treat ADHD from 30 years ago, he or she has to consider that the diagnosis was defined in a different way than it is today. Therefore, what was considered an improvement 30 years ago may not be the same as what is considered an improvement today, in part because the diagnosis is made differently, and in part because the factors that define an improvement may have also changed.
Lastly, despite all the changes in how the diagnosis of ADHD is made, the scientific community continues to acknowledge that problems of inattention and hyperactivity can lead to serious suffering and long term problems which can be helped with treatment. The first reported evidence of stimulant medication used to treat children with concentration and hyperactivity problems came in 1937 when C. Bradly showed that children in a residential facility with such symptoms had improvement in their symptoms with a compound called benzedrine. These findings have had a significant impact on child psychiatry, and will be the topic of a future entry. As always..I look forward to your comments and questions about attention deficit hyperactivity disorder, but please note that you should talk to your physician if you have specific questions about your or your loved ones' specific mental health concerns.