Are online ADHD tests accurate?

A self-observation questionnaire measures one thing only: the way you describe your own functioning at the moment you answer. That is useful information, because it puts words on situations people often live through without naming them. It is not a measurement of your brain, and it is not an examination.

Published scales were built to sort a population, not to settle the case of one person. The short World Health Organization scale, published by Ustun and colleagues in 2017 in JAMA Psychiatry, has six items. It was calibrated on general-population samples, then checked against a sample followed at New York University.

The figure that concerns you is a different one again. In the general population, 96% specificity looks excellent. But because ADHD concerns a limited share of the population, the same scale yields a positive predictive value of 67.3%: among people scoring above the threshold, about two in three meet the criteria after assessment, and one in three does not.

Three families circulate online, and the difference between them almost never appears on the page. Spotting it takes a minute and changes how you read the result.

A score summarises answers, it does not explain them. The same items about attention, forgetfulness and inner restlessness also come up for people going through marked anxiety, lasting lack of sleep, work exhaustion, or a difficult event. A short questionnaire cannot tell those situations apart, because it asks nothing about their history.

That is precisely what an assessment by a professional does, and why it takes time: it reconstructs the path since childhood, looks for what best explains the difficulties, and examines what overlaps. France's national health authority published a scoping document on the adult pathway in December 2021, but the corresponding French recommendations had not been published when this page was written.

The practical consequence is simple. A high score does not tell you what you have. It tells you the subject deserves to be raised with someone whose job it is, with concrete examples in hand.

Six markers are enough, and every one of them can be checked before you answer the first question.

• The page says where the items come from, and names the original publication when it reproduces one.
• The scoring is explained, not merely displayed.
• An update date appears on the page itself, not only in the code.
• The limits are written in the body of the page, not tucked away in small print.
• The result appears without creating an account and without leaving an email address.
• No conclusion is promised: neither confirming nor ruling out a disorder.

The sixth marker is the most telling. A ten-item questionnaire announcing a definitive result promises more than the WHO scale itself does, and the WHO scale does not.

1. Write down three to five concrete, dated situations where the difficulty showed: a meeting, a forgotten bill, a conversation you lost track of. One example is worth more than a score.
2. Check whether those situations already existed in primary school. How far back the difficulties go is the first thing a professional will look for.
3. Talk to your family doctor. They are the ones who refer you to the right professional or service, and waiting times are often long, so starting early saves months.
4. Take the questionnaire again three to six months later. Comparing two sittings says more than one, especially if your sleep or work situation changed in between.