Lec 9

Question 1

What is ADHD?

Answer 1

–persistent pattern of inattention and/or hyperactivity-impulsivity.
–Hyperactivity refers to excessive motor activity at inappropriate times (this could include running around, fidgeting, tapping, or talkativeness)
–Impulsivity refers to hasty actions that occur in the moment without any kind of forethought.
Clinically relevant forms of impulsivity typically involve possibly harmful behavior (i.e. running into traffic).

Question 2

How is ADHD diagnosed?

Answer 2

• -classified as a developmental disorder by the DSM5
• -ADHD begins in childhood, and the DSM5 requires that symptoms be present before age 12
• -these factors must be shown to impact development in a clinically significant manner meaning the adhd has to affect the individual and others to be diagnosed

Question 3

What is the difference between ADHD and ADD?

Answer 3

According to the latest version of the DSM (DSM-5), ADD is not a diagnosis
You are either predominantly inattentive, predominantly hyperactive, or a combination of both

Question 4

What are the key features of ADHD?

Answer 4

Children inevitably have occasional bouts of inattentiveness or hyperactivity – those are part of growing up. A key feature of the ADHD diagnostic is that manifestations of the disorder must appear in multiple settings.
This means that ADHD symptoms are not just limited to one place (school, for example), but appear no matter where the child is.

Question 5

What makes ADHD hard to diagnose?

Answer 5

Context matters. Signs of the disorder may be minimal or absent when the individual is under close supervision, receiving frequent rewards for good behavior, in a novel setting, or doing something interesting.
This can make the disorder challenging to diagnose, as the doctor’s office often meets all of the above criteria.

Question 6

How can ADHD cause other problems?

Answer 6

Academic performance tends to suffer
Social rejection is common as well (can result in depression)
Other comorbid disorders may also make it more challenging (e.g., ASD, OCD)

Question 7

Why is ADHD not considered an intellectual disorder?

Answer 7

ADHD is not considered an intellectual disorder per se. Nevertheless, mild delays in language, motor and social development are common in children with ADHD.
This could be a consequence of simply not paying sufficient attention to things

Question 8

What is the prevalence of ADHD?

Answer 8

–approximately 7.2%
–Male to female ratio is about 3:1
–Adult ADHD may have a prevalence as high as 2.5%. symptoms gradually reduce across the lifespan, but persist in 30-50% of cases.
impulsivity and hyperactivity tend to drop off more than attention. Many adults continue to struggle with attention their entire lives.

Question 9

What is ADHD prevalence worldwide?

Answer 9

• -ADHD prevalence appears to vary worldwide, though not by as much as is often claimed.
• -North America, when considered as a whole, has higher rates of ADHD than most other places (South America and Africa being exceptions).

Question 10

How has the DSM diagnostic criteria for ADHD changed over time?

Answer 10

• • ADD was first defined in the DSM-III with three domains: Inattention, Impulsivity, and Hyperactivity. Children required several symptoms in each domain to receive a diagnosis.
• -The DSM-IV continued with this model, but allowed for diagnosis of either symptoms of inattention or hyperactivity symptoms. These seem to be less strict diagnostic criteria.
• -The DSM5 retains similar criteria to the DSM-IV, but removed ADD

Question 11

Why is it hard to tell whether ADHD rates are increasing?

Answer 11

Since the diagnostic criteria has changed over time (from DSM-III to DSM-IV to DSM-V), it can be difficult to tell whether ADHD rates are actually increasing, or if it’s simply a matter of diagnostic criteria changing

Question 12

How do cultural factors affect the diagnoses of ADHD?

Answer 12

• -Hyperactivity and inattentiveness would not be as much of a concern in times and places where children do not go to school (ex. hunter-gatherer children)
• -On the other hand, in areas where academic achievement is prized above all else, even minor levels of inattentiveness and hyperactivity would seem pathological
• -The current DSM5 diagnostic criteria still seems to be based largely on elementary school-aged North American boys
• -disorders such as anorexia nervosa are also highly dependent on cultural context

Question 13

What is the comorbidity of ADHD?

Answer 13

Only about 1/3 of children are diagnosed with ADHD alone. The majority are diagnosed with at least one other DSM disorder

Question 14

What is oppositional defiance disorder?

Answer 14

showing defiance in the face of authority

Question 15

What is the genetical cause of ADHD?

Answer 15

–research has not yet uncovered much in the way of specific genes that might be to blame
—->Weak associations have been found with genes for the dopamine reuptake transporter and the D4 dopamine receptor
—->Theres two types of receptors for dopamine,
D1 and D2. D1 includes D1 and D5
D2 includes D2, D3, D4
—->The functioning of the reuptake transporter is altered in ADHD and the D4 receptor

Question 16

What is the etiology of ADHD?

Answer 16

–The etiology of ADHD has been suggested to be up to 80% genetic. This makes it one of the most heritable disorders

Question 17

Who is at an elevated risk of ADHD?

Answer 17

–ADHD is elevated in first-degree biological relatives of individuals with ADHD

Question 18

What can smoking affect ADHD?

Answer 18

Children with a specific mutation in the dopamine reuptake transporter (DAT1) are more likely to exhibit symptoms of ADHD if their mothers smoked during pregnancy.

• –cigarettes contain nicotine which stimulates the central nervous system and specifically elevates activity in the prefrontal cortex. People who smoke nicotine products may be self-medicating mild ADHD
• –this alters the expression of those post-synaptic receptors which then crosses the placenta and impacts the brain development of the baby

Question 19

What is perinatal hypoxia?

Answer 19

• -a temporary shortage of oxygen around the time of birth has also been linked to the development of ADHD
• -not getting enough oxygen may cause some cells to die (the hippocampus and the prefrontal cortex are some of the most vulnerable parts of the brain so if there is some trauma these are the brain regions that tend to be impacted and we see a range of symptoms as a result)
• -Perinatal hypoxia can result in a range of developmental disorders

Question 20

What is the stanford marshmallow experiment?

Answer 20

• -late 1960s, psychologist Walter Mischel
• -children (ages 4-6) were brought into the lab and offered a treat of some kind, usually a marshmallow
• -They were told that they could eat the marshmallow right away, or they could wait 15 minutes and get two marshmallows instead (the researchers said they would be back at some unspecified time)
• -The experimenter would then leave the room, and observe the child through a two-way mirror.
• -Delayed gratification is one of the functions of the frontal lobe (as it grows, it allows people to have better delay of gratification and less likely to behave impulsively)
• -Addiction is a disorder marked by failure to delay gratification
• -The children that were able to wait had better executive functioning, more successful and more likely to pursue higher education

Question 21

What are the behavioural markers of ADHD?

Answer 21

• -Children with ADHD will usually opt for immediate reward in psychological studies (such as the marshmallow study).
• —>This seems to happen regardless of previous experience in the experiment
• -Rewards apparently have less of an influence over the behavior of children with ADHD.
• —>Children’s performance in various cognitive tasks (tests of reaction time, accuracy, etc.,) improves when a reward is offered (rather than a punishment). This is not the case in children with ADHD – their performance remains low irrespective of reward.

Question 22

What is the go/no-go task?

Answer 22

• -Children with ADHD have impaired performance in go/no-go tasks
• -Go/no-go task: kids sit in front of a screen and they get told to press enter when they see certain letters (go signal). Everything else is no-go. You have to inhibit the response to press the enter key. Kids with ADHD make many errors in omission and commission. They’re not paying attention enough to hit the key properly when they see those letters and they hit the key inappropriately (error in commission)
• -Interestingly, relatives of children with ADHD also show impaired performance on these tasks, even if they don’t have the disorder themselves. This suggests a possible endophenotype.

Question 23

What is an endophenotype?

Answer 23

clustering of genes that code for specific functions that first-degree relatives may have some of that expression but may not show that exact constellation of disorder (ex eye tracking behavior in first-degree relatives of schizophrenia). We have genes that code for proteins. Certain genes are located right next to each other which could code for similar proteins. As a first-degree relative you may inherit specific protein or polymorphism (combination of DNA sequence) in your genes that makes that protein expression different (higher uptake or breakdown of dopamine in the prefrontal cortex)

Question 24

What is the Iowa gambling task?

Answer 24

• -measures risk taking and impulsivity and assess the functioning of frontal lobe
• -Patients are given 4 decks of card and they’re told to pick from the cards randomly. The object of the game is to win as much money as possible and to lose as little as possible. Unbeknownst to them, two of the decks are high risk decks (meaning the pay-offs are big but so are the losses). The other two decks are low pay-off but also low loss.
• -Patients who have frontal lobe disorders, addiction, ADHD, they tend to pick from those high risk cards repeatedly (show more risky behavior)

Question 25

What is the Dual Pathway Model?

Answer 25

• -risk taking and impulsivity point to issues with either executive function (frontal lobe) or reward function (mesocorticolimbic dopamine system), or perhaps both at the same time.
• -The Dual Pathway Model is a theory about ADHD suggesting dysfunctions in both systems are to blame

Question 26

What are the neurobiological findings of ADHD?

Answer 26

• -Children with ADHD often have reduced volume (grey matter) of certain parts of the prefrontal cortex (PFC), striatum, cerebellum, and corpus callosum
• -Problems with the PFC and striatum (caudate nucleus and putamen) are perhaps not surprising, given the deficits in executive function and reward processing seen in ADHD
• -Cerebellum is involved in fine motor control which may explain why ADHD individuals are hyperactive (tapping, tics)
• -Corpus callosum-less connections between the left and right hemispheres for ADHD

Question 27

What is pharmacokinetics and pharmacodynamics?

Answer 27

• -pharmacokinetics: how the body interacts with the drug (how the drug gets up to your brain)
• -pharmacodynamics: how the drug impacts the body

Question 28

What are nootropics?

Answer 28

categories of drugs that improve cognition.

Question 29

What is the treatment of ADHD?

Answer 29

• -The most common pharmacological treatments for ADHD are drugs of the psychostimulant variety
• -Popular drugs include methylphenidate (Ritalin/Concerta), amphetamine (Adderall), and d-amphetamine (Dexedrine).
• —>These drugs are given at low doses, in long-acting, slow-release formats that limit the “rush” that characterizes their illegal counterparts.
• -Drugs are effective in 70-90% of cases

Question 30

How were ADHD meds used in the 70’s?

Answer 30

ADHD drugs were prescribed as diet pills; adhd meds are sympathomimetic ( it mimics the sympathetic nervous system. So when the SAM pathway is affected, it pumps glucose into your bloodstream because you’ll need to fight, flight or freeze and it’s doing that so you’ll have energy. So it gives you a false satiety so you’re not hungry). This is not good because it brings up your heart rate and people were misusing them resulting in cardiac arrest

Question 31

How do ADHD meds work?

Answer 31

• -Methylphenidate (Ritalin) inhibits the re-uptake of dopamine (like cocaine) and to some extent, norepinephrine, mostly in the prefrontal cortex (PFC)
• -These drugs boost the signal so we although there are less cells (grey matter), we have more dopamine acting on those cells
• -Theory is that individuals with ADHD have decreased activity of the PFC, and increasing DA allows for increased attention
• -Giving these drugs to children with ADHD will make them lose their appetite (SAM pathway is mimicked) which can stunt their growth (however, the data shows they catch up)

Question 32

The rate of ______________ has been _________ worldwide

Answer 32

methylphenidate (Ritalin); increasing

–It’s not likely that the rate of ADHD has increased appreciably over these years (we’re recognizing it more).

Question 33

Do non-drug treatments help with ADHD?

Answer 33

Numerous non-drug treatments for ADHD have been proposed. Unfortunately, they do not seem to be very effective in controlled studies

Question 34

What are the ethics of ADHD?

Answer 34

• -Because ADHD is mostly a disorder of childhood, its treatment requires special consideration
• -It is often suggested that children are overmedicated and overdiagnosed, or that medication is used as a substitute for effective parenting/schooling
• -Children are not small adults, so studies of drug effects on adult brains cannot be safely generalized to children
• -ADHD symptoms do tend to improve on their own as the child ages. Should we just leave ADHD alone and let it resolve itself? Academic and social success during childhood strongly influences the rest of the individual’s life so the risk of meds may be a fair tradeoff

Question 35

What are the long-term effects of psychostimulants?

Answer 35

Chronic methylphenidate treatment in young rats reduces the rewarding power of cocaine in adulthood.
Chronic amphetamine treatment reduces dopamine terminals in the striatum of monkeys