Attention Deficit Hyperactivity Disorder

What is ADHD?

A disorder characterized by: attention deficits (difficulty sustaining attention/poor oncentration) hyperactivity Impulsivity mood swings short temper, aggressiveness high sensitivity to stress impaired ability to make & follow plans Fidgeting, constant motion or activity Disorganization. Difficulty getting along with others Have difficulty reading social cues

DSM-IV Criteria for ADHD Either A or B: A. 6 or more manifestations of inattention present for at least 6 mos.

To a maladaptive degree & greater than what would be expected, given person’s developmental level (e.g., careless mistakes, not listening well, not following instructions, easily distracted).

B. 6 or more manifestations of hyperactivity-impulsivity present for at least 6 mos. To a maladaptive degree & greater than what would be expected, given person’s developmental level (e.g., squirming in seat, running about inappropriately).

Some of the above present before age 7. Present in 2 or more settings (e.g., at home & at school or work) Significant impairment in social, academic, or occupational

functioning Not part of other disorders such as schizophrenia, an anxiety disorder,

a mood disorder.

What distinguishes ADHD from normal “hyperactivity?”

All kids have some level of hyperactivity, so what makes ADHD unique??

A diagnosis of ADHD is appropriate if maladaptive behaviors are extreme for a particular developmental period, persistent across different situations, & linked to significant impairments in functioning. The diagnosis is reserved for truly extreme cases!!!

The diagnosis does not apply to children who are rambunctious, active, or slightly distractible, in the early schools years (this is normal for this age).

Recent Hot Issue in the dramatic increase of diagnosed cases of ADHD--- Has ADHD become a “designer diagnosis” for children

who are more active & difficult to control??

Possibly!! Active behavior that would have been considered “normal” years ago, is now considered aberrant.

The Result: A push to medicate kids who may be difficult to control or deal with in classroom settings.

ABA could be used here, in place of drugs!!!!

General Examples of problem behaviors that are affected by ADHD:

Academic difficulties-may do poorly in school due to impulsivity & inattentiveness.

Social behaviors-may be tactless, obstinate, bossy, aggressive, have difficulty getting along with peers.

Occupational difficulties-may have difficulty taking orders from others, difficulty dealing with co-workers, struggle to be productive, etc.

Antisocial behaviors – being aggressive, having

difficulty relating to others.

Specific problem behaviors of ADHD: Kids can’t sit still during classroom activities & at

mealtimes.

Can’t stop talking at times when required to be quiet.

Activities & movements are haphazard & constant.

They quickly wear out shoes & clothing, smash their toys, exhaust family members & teachers.

Have difficulty getting alone with peers & establishing friendships.

Specific problem behaviors (contd.) They may misinterpret others’ intentions, such as

acting aggressively because they assume that a neutral action by a peer was meant to be aggressive.

They may know correct social behavior in situations, but have difficulty transforming the information into appropriate behavior in real-life social interactions.

****About 15-30% of kids with ADHD have a learning disability. Half of kids with ADHD are placed in special ed classrooms.

When does ADHD usually become a problem? During the preschool years, when children have

difficulty controlling their activity & interacting with their peers.

However, ADHD may also become a problem in adolescence.

65 - 80% of kids with ADHD still meet criteria in

adolescence & adulthood.

Prevalence of symptoms in ADHD & normal adolescents (Barkley, 1990)

Symptom ADHD% Normal% Fidgets 73.2 10.6 Easily distracted 82.1 15.2 Difficulty remaining Seated 60.2 3.0 Blurts out answers 65.0 10.6 Difficulty (attention) 79.7 16.7 Interrupts others 65.9 10.6 Talks excessively 43.9 6.1

Three types of ADHD:

1. Predominantly Inattentive type: Children with problems primarily of poor attention (ADD).

2. Predominantly Hyperactive-Impulsive type: Children whose difficulties result primarily from hyperactive-impulsive behavior.

3. Combined type: Children who have both sets of problems. This type makes up the majority of diagnosed cases. Most at risk for conduct disorder as well.

Recent thoughts on the classification of ADHD:

Evidence suggests ---it may be best to think of ADHD as two separate disorders:

1. One of inattention 2. One of hyperactive/impulsive behavior

Most theory & research does not make a distinction.

ADHD & Comorbility

ADHD is often comorbid with:

Anxiety Depression (unipolar depression) Conduct Disorder

What is the prevalence of ADHD?

Difficult to determine--due to the varied definitions of the disorder & # of populations sampled.

Estimates—2- 7% in the US 3 –7% worldwide

Who is affected more: Males or Females??

Males are 2-3 times more likely to be diagnosed with ADHD than are females.

Figures change depending on sample (those referred to a clinic vs. general pop.).

Clinic samples show greater percentage of males, since they were referred to the clinics because of antisocial & aggressive behaviors.

Girls & ADHD:

1. Like boys with ADHD, girls diagnosed with combined type were more likely to have a comorbid diagnosis of conduct disorder or oppositional defiant disorder than girls without ADHD.

2. Girls with combined type have more disruptive behavior symptoms than girls with inattentive type.

3. Girls with combined type were viewed more negatively by peers than girls with the inattentive type and girls without ADHD. Girls with inattentive type were also viewed more negatively than the comparison girls.

4. Girls with ADHD had a # of neuropsychological deficits such as executive functioning (planning, problem solving), compared with girls without ADHD.

What causes ADHD?

Theories:

• Genetics • Prenatal/perinatal factors • Environmental Toxins • Psychological factors • Neurological factors

Genetics & ADHD:

•There is a genetic predisposition for ADHD.

• When parents have ADHD, 50% of their child do too.

Adoption & a # of identical twin studies show a genetic link. MZ concordance rates are as high as .70 - .80 (Tannock, 1998).

Prenatal/Perinatal Factors: Factors predictive of ADHD:

•Low birth weight (perinatal)• Maternal smoking (prenatal) – increases dopamine

release in baby’s brain—leading to hyperactivity & behavioral disinhibition.

--Millberger et al., (1996) reported that 22% of mothers of kids with ADHD smoked a pack of cigarettes per day during pregnancy, compared with 8 % of mothers whose kids did not develop ADHD.

• Alcohol (prenatal)

Environmental toxins & ADHD: A. Dietary factors: In 1970s Feingold argued that food additives upset the CNS

of hyperactive children. He proposed a diet free of artificial additives (flavors/colors).

Well controlled studies do not support the efficacy of the Feingold diet (Goyette & Conners, 1977).

Refined sugar also not found to be liked to ADHD. B. Non-food related substances: Although it was theorized that lead poisoning may be

linked with hyperactivity & attentional problems, kids with ADHD don’t have higher lead-levels than age-matched controls.

Psychological Theories 1. Bettelheim’s (1970s) Diathesis-Stress theory of

ADHD.

This view argues that kids with predisposition for ADHD coupled with authoritarian parenting develop the disorder.

As parent becomes more impatient & negative with the child, the parent-child interactions become battles & a disruptive-disobedient pattern is formed. This generalizes to other settings besides the home (e.g., school, social settings, etc.).

2. Learning theories

Hyperactivity could be reinforced by the attention it elicits, leading to increases in the frequency of the negative behaviors.

Ross & Ross (1982) argue that hyperactivity may be modeled on the behavior of parents & siblings. However, research has not supported this.

Neurological factorsBrain function & structure differs for children with &

without ADHD.

•The Frontal lobes of kids with ADHD are under responsive to stimulation & cerebral blood flow is reduced.

• The frontal lobes, caudate nucleus, & globus pallidus of kids with ADHD are smaller than normal.

• Kids with ADHD show poorer performance on neuropsychological tests of frontal lobe function (such as inhibiting behavioral responses).

Neurological Factors (contd.)

Kids with ADHD also have a smaller than average right prefrontal cortex. The right prefrontal cortex is thought to be associated with “behavioral withdrawal.” (Left prefrontal-behavioral approach).

The cerebellum is also smaller than usual. Note that cerebellar dysfunction is associated with difficulty switching attention.

Its unclear whether brains were different to begin with or developed differently based on their experience.

Measuring ADHD behavior: 1. Choice-Delay Task- Ss are given a choice

between an immediate reward of a lesser value or a delayed reward of a greater value and asked to pick one.

E.g., Which would you prefer, $5 now or $6 tomorrow? Or which would you prefer, a cookie now or a slightly larger cookie in 15 min.?

People w/ADHD—more likely than others to choose the smaller, but more immediate reward. This is used to index impulsivity or difficulty inhibiting a behavior.

2. The Stop Signal Task Ss are asked to watch a screen or listen for a

sound. When they hear it, they are to press a button as fast as possible.

On some occasions, another stimulus is presented a split sec after the first stimulus & is used to indicate the Ss must not press the button. Thus, Ss have to learn to inhibit their button pressing.

With the intermediate delays, people with ADHD are more likely than controls to press the button.

3. The Attentional Blink Task Ss watch a series of black letters flashed on a screen, a

new one every 90 ms. In each set, one of the letters is blue. Another letter, designated as the “probe” letter, might or might not appear after the blue letter. The task is first to name the blue letter & the to say whether or not the probe letter appeared after the blue letter.

Most people miss the probe letter (they say “no” even though it was present) if it appears about two 2 – 7 letters after the blue letter. This is called the attentional blink; you pay attention to the blue letter for about 200-600 ms after seeing it, so you have trouble paying attention to anything else.

Attentional blink (contd.)

The same is more evident for people with ADHD, they usually miss the probe letter even if it arrives almost a second after the blue letter.

Interpretation—people with ADHD have trouble controlling their attention; they can’t shift it when they need to.

ADHD: Treatment 1. Medication- stimulants prescribed since

1960s (Ritalin).

Stimulant effects-paradoxical –improve ability to concentrate/reduce disruptions.

In double-blind designed studies, 75% of kids with ADHD showed dramatic improvements with stimulants.

How does Ritalin work?

Amphetamine & methylphenidate stimulate the release of dopamine to the postsynaptic receptors.

They produce their maximum effects on dopamine about 1 hour after someone takes a pill, and 1 hour is also the time of maximum behavioral benefit, so the drug effects behavior through altering dopamine activity.

Treatment (cond)

2. Psychological techniques— Behavioral techniques based on operant

conditioning work well. Applied Behavior Analysis

Programs have demonstrated at least short-term success in improving social & academic behavior.

Behavior therapy Kids are reinforced for behaving appropriately

(e.g., remaining in seats & working on assignments).

Point systems & star charts are useful; kids earn points or stars for good behaviors that allow them to earn tangible rewards.

Focus of therapy is on improving academic & social functioning, less emphasis is applied to reducing unwanted behaviors (hyperactivity).