Attention Deficit and Hyperactivity Disorders

 
Meet Cody
 

 

 

About a Year ago, Cody was Diagnosed with ADHD. He's going to help us along in our journey today. Yay.

 

  

Of particular interest to ADHD researchers are the areas of the brain known as the prefrontal cortex and the basal ganglia. These centers are thought to control behavior and behavior planning, and are thus critical in a behavioral disorder such as ADHD.

 

 

You may be asking yourself, what is ADHD?

 

 

ADHD is a disorder of the brain which results in loss of concentration, hyperactivity, and/or impulsiveness.

 
 
Statistics

 

  • •ADHD affects 4-12% of school-aged children (2 million kids).

  • •Boys are 3 times as likely to be diagnosed than girls.

  • •Diagnosis typically occurs between the ages of 5 to 12 years, although adult ADHD isn’t uncommon.

 
 

The Brief History

  • •ADHD has been a recognized medical condition since the early 1900’s.

  • •ADHD was once known as “minimal brain dysfunction” and thought to be caused by minor head injuries, complications from birth, or an early infection.

 

So What Causes ADHD?

 

  • It is unknown what exactly causes ADHD at this point.

  • Research suggests that Dopamine and Norepinephrine imbalances play a key role.

  • MRI Studies indicate that in some cases, the prefrontal cortex and basal ganglia regions of affected people are slightly underdeveloped.
     
How is ADHD diagnosed?

Patient history as well as a clinical evaluation is plugged into an algorithm such as this one, and the results determine whether or not the patient has the disorder or another type of behavioral disorder.

DSM-IV Guidelines are strictly followed.
The 3 Types of ADHD

 

  1. Predominantly Hyperactive-Impulsive Type

  2. Predominantly Inattentive Type

  3. Combined Type
     
3 Classes of medication

  • Stimulants

  • Adjuvants to Stimulants

  • Alternatives

 
 

 

  
Stimulants

Methylphenidates

Focalin
Methylin
Ritalin
Concerta
Generics

 Stimulants

Amphetamines

Adderall
Dexadrine
Dextrostat
Dexadrine Generics

 Adjuvants

α2-Adrenergic agonists

Clonidine
Guanfacine

 Alternatives

Selective Norepinephrine Reuptake Inhibitors

Strattera
 
   
How it all works:

The stimulants work by increasing production of Dopamine via agonist binding sites on the presynaptic neuron. This causes increased amounts of Dopamine, which in turn counters any imbalance that may have occured. These stimulants also have an effect on the reuptake of Dopamine, but it is not well understood.

The alpha-2 stimulants work in much the same way, only on the norepinephrine agonist binding sites.

The selective norepinephrine reuptake inhibitors work just as they are named, the slow reuptake of norepinephrine in the synapse. This causes the norepinephrine to have a prolonged effect without increasing the amount present.

It is currently thought that autoreceptors on the presynaptic neuron act as sort of a thermostat for the cells. They aid in monitoring neurotransmitter concentrations and help regulate stimulatory and depressant responses.
 

American Academy of Child and Adolescent Psychiatry, International Guidelines Center
American Academy of Pediatrics (http://www.aap.org)
Shire Medical Educational Resources, 2002
Bear, MF et al. Neuroscience: Exploring the Brain. Lippincott Williams and Wilkins. 2001.
 

Special Thanks To:
Drs. Jeff and Sherrye Craig, Central Arkansas Pediatrics
Wayne- The Lilly Pharmaceuticals Representative

Online Resources:

Medline Plus (http://www.nlm.nih.gov/medlineplus/attentiondeficitdisorderwithhyperactivity.html)

National Attention Deficit Disorder Association (http://www.add.org)

National Institue of Mental Health (http://www.nimh.nih.gov)