ATTENTION DEFICIT HYPERACTIVITY DISORDER

WHAT IS ATTENTION DEFICIT HYPERACTIVITY DISORDER?

Name changed from ADD to ADHD in 1994 (APA)

Neurobehavioral disorder (NIH)

3-5% American children affected

Affects ability to stay on task – age appropriate inhibitions

DSM-5 Criteria

Six+ symptoms – by age 16Five+ adolescents age 17 & adultsSymptoms present by age 12Symptoms present for at least 6 monthsSymptoms present in two or more settingsInappropriate for developmental level

Three subtypes of ADHD:

Predominantly Inattentive

Predominantly Hyperactive-Impulsive

Combined Presentation

PHYSIOLOGICAL ASPECTS OF ADHD

Most studied condition in child psychiatry   Exact causes and the mechanisms

not understood Neurological disorder Two neurotransmitters involved

Norepinephrine Dopamine

Brain imaging:

Brain matures in a normal pattern delayed approximately 3 years

Brain regions – thinking, paying attention and planning

Cortex – overall delayed maturation

Corpus Callosum – abnormal growth patterns

Heritability

Familial studies – risk among parents and siblings of children with ADHD increased 2 to 8 fold

Adoption studies – biological relatives more likely than adoptive relatives

Pooled analysis of 20 twin studies – heritability 76%

Recent study (Burt, 2009) – 60% heritability Plethora genes – small but significant effect

Comorbidity:

Learning disability Oppositional defiant disorder Conduct disorder Anxiety Depression Bipolar disorder Tourette syndrome

Dopamine & ADHD:

What is dopamine?

Neurotransmitter – Chemical messenger carries signals between neurons and other cells in body

Neurohormone - hormone secreted by a specialized

neuron into the bloodstream, cerebral spinal fluid or the intercellular spaces in the nervous system

Dopamine and ADHD

Too little dopamine

Dopamine transporters take up too much dopamine before it can be passed from one brain cell to another 

Inhibitory  neurotransmitter – calming

Ability to control impulses

Dopamine production

Substantia nigra

Ventral tegmental area

Dopamine Synthesis:

Hypothalamus

Arcuate nucleus

Caudate nucleus

Treatment:

Medications:

Stimulants (Ritalin®, Adderall®)

Non-stimulants (Strattera®, Intuniv®)

Behavioral Therapy: Individual Family

PEER REVIEWED JOURNAL ARTICLES

LINEAR AND NON-LINEAR EEG ANALYSIS OF ADOLESCENTS WITH ATTENTION-DEFICIT/HYPERACTIVITY DISORDER DURING A COGNITIVE TASK

Empirical study

Adolescent boys

EEG dynamics

Cognitive task

Methods: Approximate entropy

(ApEn) - measure the complexity of the EEG

ApEn likelihood that similar patterns of observations will not be followed by additional similar observations

series 1: (10,20,10,20,10,20,10,20,10,20,10,20...), which alternates 10 and 20.

series 2: (10,10,20,10,20,20,20,10,10,20,10,20,20...

Results:

Mean ApEn – significantly lower in adolescents with ADHD than control group when performing cognitive task (not at rest)

Impaired cortical (cerebral cortex) information

processing

Lower complexity of the EEG

Topographic comparisons of ADHD subjects and healthy subjects using the ApEn calculated from EEGs recorded during an eyes-open resting condition and during an auditory attentional task.

Objective Diagnosis of ADHD Using IMUs

Empirical study Miniature wireless inertial sensors Levels and patterns of movement in children

using inertial measurement units (IMUs) Accelerometers – tool measures acceleration Gyroscopes – tool measures orientation The IMUs were used to analyze and characterize the

subjects' motion

High-tech 3D-accelerometer hidden in a belt 

A movement sensor is clipped onto a belt worn around the waist

GyroBelt driver

Results:

IMU’s promising tool for objective ADHD diagnosis Previous studies – Acceleration measurements Gyroscope measurements have a good predictive

capability for discrimination between ADHD and non-ADHD subjects

More than half the selected features came from the sensor at the child's waist - “global” motion is a better indicator of hyperactivity than “local” motions (foot tapping, finger drumming etc.)

Why Attention-Deficit/Hyperactivity Disorder Is Not a True Medical Syndrome 

Theoretical study Thesis - Attention-Deficit/Hyperactivity Disorder (ADHD)

cannot be a valid diagnostic category. Critical of DSM criteria

EXAMPLE:Jack - 6 symptoms inattention zero hyperactivity (ADHD)

Allen – 5 symptoms inattention zero hyperactivity (NOT)

Mark – 6 symptoms hyperactivity zero inattention (ADHD)

Steve – 5 symptoms hyperactivity zero inattention (NOT)

Bob – 5 symptoms inattention & 5 symptoms hyperactivity (NOT ADHD)

Lindstrom  asks "What are the odds that the postulated syndrome of ADHD will match up with some underlying disorder…These odds seem pretty slim..."

Non pathological reasons for ADHD

Boring teachers Boring lessons Boring books Infrequent rewards

Conclusions:

Symptoms like inattentiveness, hyperactivity or impulsivity - symptoms of real disorders it is not likely that there is one organic or mental dysfunction that accounts for the complex of symptoms labeled ADHD

No reason to think the huge behavioral category of ADHD can be traced back to some unknown type of harmful dysfunction in the individual.

Conclusions continued:

No reason to think that clinical levels of hyperactivity and inattentiveness always must be caused by pathology.

As with nausea, physicians should view hyperactivity and inattentiveness as nothing more than possible symptoms of disorder

ADHD and Community Psychology

Objective methods of diagnosis Provide information on benefits and dangers

of medication Determine if system changes can have an

affect on symptoms