You're right, defining a "disorder" is hardly a boolean question. ADHD has been studying extensively and there is substantial evidence for biological origins. For one, heritability very high, reported to be somewhere between 0.75 and .9, only slightly less than traits such as height.
Significant differences in brain neurophysiology are well-documented in ADHD (vs. non-ADHD people), and show genesis of the condition is multi-factorial. Calling ADHD a "disorder" implies the condition has physiological origins but is not attributable to a narrow/distinct range of factors like a condition termed a "disease" (such as viral illness, etc.).
The issue of diagnosis conceptually reflects a state where "malfunction" and "maladjustment" or "maladaptation" coincide. IOW malfunction is relevant when it's maladaptive, that is lacks fitness to a problem-space. In a computer application a bug (malfunction) can lurk undetected as long as the code containing the error is not invoked. But when some refactoring exposes the bad code to invocation, that code is maladaptive and the result is dysfunction of the application.
An example is an ADHD individual with trouble prioritizing who takes longer than peers to complete tasks. Not a problem when deadlines are minimal. But thrust into a role where timely performance is required risks failure, loss of a job, etc. The individual's malfunction is then maladaptive, which could prompt the person to seek help to mitigate malfunction and improve adaptability to realities of employment.
Consequently there's no across the board right or wrong answer to the "correct" way to regard ADHD characteristics. Also I agree with you that "mental illness" is a misleading term that could profitably be expunged from our vocabulary. However were that to happen the conditions that are labeled as such are still very real and will in many cases continue to need treatment regardless of the labels we apply.
Significant differences in brain neurophysiology are well-documented in ADHD (vs. non-ADHD people), and show genesis of the condition is multi-factorial. Calling ADHD a "disorder" implies the condition has physiological origins but is not attributable to a narrow/distinct range of factors like a condition termed a "disease" (such as viral illness, etc.).
The issue of diagnosis conceptually reflects a state where "malfunction" and "maladjustment" or "maladaptation" coincide. IOW malfunction is relevant when it's maladaptive, that is lacks fitness to a problem-space. In a computer application a bug (malfunction) can lurk undetected as long as the code containing the error is not invoked. But when some refactoring exposes the bad code to invocation, that code is maladaptive and the result is dysfunction of the application.
An example is an ADHD individual with trouble prioritizing who takes longer than peers to complete tasks. Not a problem when deadlines are minimal. But thrust into a role where timely performance is required risks failure, loss of a job, etc. The individual's malfunction is then maladaptive, which could prompt the person to seek help to mitigate malfunction and improve adaptability to realities of employment.
Consequently there's no across the board right or wrong answer to the "correct" way to regard ADHD characteristics. Also I agree with you that "mental illness" is a misleading term that could profitably be expunged from our vocabulary. However were that to happen the conditions that are labeled as such are still very real and will in many cases continue to need treatment regardless of the labels we apply.