TBH I found this article a bit poorly written, especially around the core of the symptoms*. It does not even list out what exactly are the kinds of things to look for when you are in say your 30's or something and suspect you have ADHD. The list of recommendations though are good, especially simplifying note taking, which can be a drag to keep upto date.
I would also add meditation and getting a good counselor/licenced therapist(they are hard to find). You can find a good counselor in a few ways: from someone who does your formal neuropsych eval, ask your kid's doctor. Look at psychologytoday.com and filter the list and run through it. For ADHD which does not accompany severe cognitive impairments you want to likely look at a CBT coach(Phd,PsyD holders) to help. Someone who knows what they are doing.
* If you think you have ADHD or ADD please consult the complete DSM-V manual[0](https://www.ncbi.nlm.nih.gov/books/NBK519712/table/ch3.t3/) and at least try and match your symptoms up from your past experiences. I would highly recommend a neuropsychlogical evaluation test. Google for it.
Here is an abridged list[1] of symptoms from DSM5 for ready reference:
Inattention: Six or more symptoms of inattention for children up to age 16, or five or more for adolescents 17 and older and adults; symptoms of inattention have been present for at least 6 months, and they are inappropriate for developmental level:
◦ Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities.
◦ Often has trouble holding attention on tasks or play activities.
◦ Often does not seem to listen when spoken to directly.
◦ Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, becomes sidetracked).
◦ Often has trouble organizing tasks and activities.
◦ Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).
◦ Often loses things necessary for tasks and activities (e.g., school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).
◦ Is often easily distracted.
◦ Is often forgetful in daily activities.
Hyperactivity and Impulsivity: Six or more symptoms of hyperactivity-impulsivity for children up to age 16, or five or more for adolescents 17 and older and adults; symptoms of hyperactivity-impulsivity have been present for at least 6 months to an extent that is disruptive and inappropriate for the person’s developmental level:
◦ Often fidgets with or taps hands or feet, or squirms in seat.
◦ Often leaves seat in situations when remaining seated is expected.
◦ Often runs about or climbs in situations where it is not appropriate (adolescents or adults may be limited to feeling restless).
◦ Often is unable to play or take part in leisure activities quietly.
◦ Is often “on the go,” acting as if “driven by a motor.”
◦ Often talks excessively. ◦ Often blurts out an answer before a question has been completed.
◦ Often has trouble waiting his/her turn.
◦ Often interrupts or intrudes on others (e.g., butts into conversations or games).
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[0] https://www.ncbi.nlm.nih.gov/books/NBK519712/table/ch3.t3/
[1] Hallowell, Edward M.; Ratey, John J.. ADHD 2.0 (p. 138). Random House Publishing Group. Kindle Edition.