{'fraction_non_alphanumeric': 0.032640949554896145, 'fraction_numerical': 0.010385756676557863, 'mean_word_length': 5.148936170212766, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Attention deficit hyperactivity disorder in adulthood

Attention deficit disorder may persist into adult life and have a genetic basis

A behavioural syndrome of childhood characterised by overactivity, excitability, and explosive behaviour has been recognised since the turn of the last century and is now thought to be, at certain ages, the most common disorder of childhood.1 The disorder is now recognised in the terminology of ICD-102 as “hyperkinetic disorder”, and in DSM-IV3 as “attention deficit hyperactivity disorder” (AD/HD). The cardinal features of overactivity and impaired attention should be pervasive—that is, evident in more than one situation, and observable before the age of six (ICD-10) or seven years (DSM-IV), though they are usually evident well before that. DSM-IV subclassifies AD/HD into predominantly inattentive, predominantly hyperactive–impulsive, and combined subtypes; ICD-10 insists on the presence of both inattention and hyperactivity for a diagnosis of hyperkinetic disorder.

The prevalence varies according to which set of diagnostic criteria is used, DSM-IV or the more restrictive ICD-10. Using the latter, prevalence in the United Kingdom is 1.5% among seven year old boys in British inner cities4; in the USA using DSM-IV criteria, this may rise as high as 9.5%.5 Sex differences are far more consistently reported, and boys regularly exceed girls in a ratio of 2.5:1. There is a substantial comorbidity with conduct disorder and oppositional deviant disorder, although the two conditions are not readily separated, and with reading disorder, obsessive compulsive disorder, multiple tic disorder, and Tourette’s syndrome.

The hyperactive child syndrome as it was originally conceived was thought to be a condition of childhood. Experienced clinicians could write: “In later years this syndrome tends to wane spontaneously and disappear. We have not seen it persist in those patients we have followed to adult life.”6 This view was widespread and was formally acknowledged in …