How ADHD presents is not alike for everyone. This is why it may be so difficult to accept as a disorder or why some people may think of the disorder as a myth. Personally, I don't think this debate is necessary, but what is important is to help people who are inattentive and/or hyperactive cope better in life and to help them achieve whatever it is they want out of life, preferably without the need for drugs. It is more important to let them be who they need to be while helping them function better rather than to shut them down with drugs.
Example of differences:
Niggs (2006) says that people with ADHD are "anxious, whereas others are fearless; some have motor coordination problems, while others are good athletes; some are hostile, whereas others are friendly; some have high IQs and find schoolwork easy to understand, while others have learning disabilities or below-average language skills. Likewise, some have average psychological test scores on neuropsychological examination, but others have multiple impairments".
Nigg, J. T. (2006). What Causes ADHD? Understanding What Goes Wrong and Why. London: The Guildford Press, p. 175.
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