Attention deficit hyperactivity disorder


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Attention deficit hyperactivity disorder

Psychological disorders

Mood disorders

Major depressive disorder


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Seasonal affective disorder

Premenstrual dysphoric disorder

Anxiety disorders

Generalized anxiety disorder

Social anxiety disorder

Panic disorder



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Obsessive-compulsive disorder

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Narcolepsy (NORD)

Sexual dysfunction disorders

Erectile dysfunction

Male hypoactive sexual desire disorder

Orgasmic dysfunction

Female sexual interest and arousal disorder

Genito-pelvic pain and penetration disorder

Pediatric disorders

Attention deficit hyperactivity disorder

Disruptive, impulse control, and conduct disorders

Learning disability

Fetal alcohol syndrome

Tourette syndrome

Autism spectrum disorder

Rett syndrome

Shaken baby syndrome



Psychiatric emergencies


Serotonin syndrome

Neuroleptic malignant syndrome

Psychological disorders review

Mood disorders: Pathology review

Amnesia, dissociative disorders and delirium: Pathology review

Personality disorders: Pathology review

Eating disorders: Pathology review

Psychological sleep disorders: Pathology review

Psychiatric emergencies: Pathology review

Drug misuse, intoxication and withdrawal: Hallucinogens: Pathology review

Malingering, factitious disorders and somatoform disorders: Pathology review

Anxiety disorders, phobias and stress-related disorders: Pathology Review

Trauma- and stress-related disorders: Pathology review

Schizophrenia spectrum disorders: Pathology review

Drug misuse, intoxication and withdrawal: Stimulants: Pathology review

Drug misuse, intoxication and withdrawal: Alcohol: Pathology review

Developmental and learning disorders: Pathology review

Childhood and early-onset psychological disorders: Pathology review


Attention deficit hyperactivity disorder


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USMLE® Step 1 questions

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High Yield Notes

6 pages


Attention deficit hyperactivity disorder

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USMLE® Step 1 style questions USMLE

of complete

An 11-year-old boy is brought to the pediatrician by his parents for evaluation of behavior problems. The patient has been frequently interrupting his parents when they are speaking with others. He often forgets to complete tasks assigned to him, such as cleaning up toys or taking out the trash and is easily distracted. His parents state that when they speak to him, he often does not seem to listen. The patient has been performing poorly in school, and his parents are scheduled to meet with the teacher next week. Past medical history is notable for a tonsillectomy at age 9. Height and weight are consistently tracking at the 50th percentile. Physical examination is unremarkable. Which of the following would be most useful in identifying the patient’s underlying condition?  

External References

First Aid








Attention deficit disorder (ADD)

amphetamines for p. 243

Attention-deficit hyperactivity disorder (ADHD) p. 580

drug therapy for p. 596

smoking and p. 638

sympatholytic drugs for p. 244

Tourette syndrome p. 580

treatment p. 726


Content Reviewers

Rishi Desai, MD, MPH


Tanner Marshall, MS

What most people know—or think they know—about attention deficit disorder, or ADD, is that it’s used to describe somebody who can’t stay focused…and when they REALLY can’t focus, they have attention deficit hyperactivity disorder, or ADHD. This continuum from one to the next isn’t quite how it works, though.

ADD and ADHD are actually synonymous, as in, they’re the same.

ADD’s an outdated term used prior to 1987, after which it evolved into ADHD to encompass more of the symptoms that people with ADHD often experience, which in addition to being inattentive, includes both hyperactivity and impulsiveness.

So somebody might be diagnosed with ADHD because they have symptoms related to not being able to pay attention, but they also might be diagnosed with ADHD if they have symptoms relating to being overly active and impulsive.

They might also have ADHD if they have symptoms of both.

According to the diagnostic and statistical manual for mental disorders, the fifth edition, the most recent update being in 2013, ADHD is split into these three subtypes: inattentive, hyperactive-impulsive, or both.

Inattentive and hyperactive-impulse have a set of nine symptoms.

For example, someone with the inattentive subtype might make careless mistakes, or not listen, or be easily distracted; and someone with the hyperactivity and impulsive subtype might fidget, or squirm around, or get up from their chair often.

Now, you might be thinking that everyone fidgets now and then, right? Well a diagnosis is given when someone has 6 of the 9 symptoms for either subtype for at least 6 months.

Most commonly though, children have symptoms of both subtypes and therefore have the combined subtype.

Since ADHD is considered a neurodevelopmental disorder, the symptoms also have to have started between age 6 and 12, and the behavior can’t be appropriate for their age.

Alright, but what causes someone to be hyperactive, or impulsive, or inattentive? Well, as you might guess, it’s pretty complicated...and we don’t really know, probably a lot of different factors, and ultimately they all fall into some combination of environmental and genetic factors.

One interesting clue to a genetic component of ADHD is looking at families—for example, a child with a sibling that’s been diagnosed with ADHD is more likely to develop it themselves.

Furthermore, if those siblings are identical twins, meaning they have the same DNA, their chances of developing ADHD is considerably higher.

Having identical DNA doesn’t mean that the twin is definitely going to develop ADHD, though, which again, suggests that both genetic factors and environmental factors play a part.

As to a specific gene, it’s probably not one single gene that leads to ADHD, but rather multiple genes that determines how severe their symptoms are.


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