PSYCH - ADHD Flashcards
ADHD is characterized by 3 core symptoms:
Which one is the most common symptom?
inattention (most common)
hyperactivity
impulsivity
What is the DSM criteria for ADHD?
1) symptoms present for at least 6 months
2) onset before 12 yo
3) clinically significant impairment in ≥2 settings: academics, jobs, social, home
4) not due to another psychiatric or medical dysfunction (ie can’t have schizophrenia and ADHD at the same time)
What are the long-term complications of unmanaged ADHD?
- negative perception/low self-esteem
- “fall behind” in social/academic skills (develop truancy, learning disabilities)
- experimentation with tobacco and alcohol)
What is the catecholamine hypothesis of ADHD? What evidence best supports this hypothesis?
dysregulation of dopamine or NE neurotransmission, especially in the CNS, leads to ADHD
evidence: meds effective for ADHD affect the dopamine or NE activities
Which brain regions are most affected in patients with ADHD? How is this determined?
decreased activity in:
- superior prefrontal cortex
- premotor cortex
determined via PET scanning
How do normal brains process information (focus attention + mediate response selection) as compared to those with ADHD?
Be sure to mention the brain region that is most involved in this particular function.
The anterior cingulate cognitive division (ACcd) plays a central role in attentional processing by 1) focusing one’s attention to a particular stimulus and 2) mediating response selection.
Thus, ACcd is a pathway that is used for processing information in normal brains, but NOT used in the ADHD brain
How is ADHD assessed?
ADHD is a clinical diagnosis (based on collateral information from parents, teachers, significant others)
How do the mechanisms of action of amphetamines and methylphenidate (FDA approved stimulants)?
What are the side effects of these drugs? What are the effects of an over dose?
What is one of the concerning issues with stimulants?
amphetamine: STIMULATE RELESE of dopamine*, NE, Epi & BLOCKS REUPTAKE
methylphenidate: BLOCKS REUPTAKE of dopamine and NE
General Side effects: insomnia + decreased appetite
Overdose: psychosis, cardiac arrhythmias, seizures, death
Concerning issue: NON-compliance
Both Amphetamines and Methylphenidate have very short half-lives (cleared from the body in ~4 hours). What are some of the newer drugs (methylphenidate-based) that have longer half-lives?
What technologies do they use to extend the half-lives of the drugs?
Focalin - uses only the active isomer of methylphenidate, thereby improving the efficacy of the drug at half the dose
Ritalin - SODA technology
Concerta: OROS technology
Adderal - extended release form
How is the SODA, OROS, and Extended Release (XR) technology the same? How are they different?
Same: all work to “prolong” the half-life of the drug/minimize the number of times a medication has to be taken.
Different:
SODA: bimodal release (50% of capsules are immediate release + 50% are polymer coated, which releases approx. 4 hours after ingestion)
OROS technology (Osmotic-controlled Release Oral-delivery System) - tablet with rigid water permeable coating and small laser-drilled holes; as the tablet passes through the body, the osmotic pressure of water enters the tablet and pushes the active drug through the opening in the tablet.
XR: drug is embedded in a matrix of insoluble substance, such that the dissolving drug must find its way out through the holes in the matrix. In time, the entire dose is released into the system while the polymer is excreted via normal digestion
Short-acting and Long-acting stimulants (Amphetamines and Methylphenidate) both have different side effect profiles. What are they?
Short-acting:
- rebound effect - as Rx wears off, there will be more pronounced distractibility, hyperactivity, mood changes
- compliance and abuse - they have to be taken multiple times a day
Long-acting:
- more insomnia
- more appetite suppression, weight loss, growth suppression
FDA-approved non-stimulants can also be used to treat ADHD:
Atomoxetine
Guanfacine XR
Clonidine
What is their mechanisms of action?
Atomoxetine: NE reuptake inhibitor
Guanfacine XR: alpha-2 agonist
Clonidine: alpha-2 agonist
Guanfacine XR and Clonidine are both used as non-stimulants for ADHD treatment.
What core symptoms are they best used for?
Sedation is a common side effect of these two drugs. Which one is more sedating?
good for impulsivity and hyperactivity but NOT for inattention
Guanfacine XR is more sedating
What are some off-label/non-FDA approved drugs that are used to treat ADHD?
imipramine, desipramine, nortriptyline (TCA) reuptake inhibitor of NE + serotonin
bupropion (NDRI) - reuptake inhibitor of NE + dopamine
Venlafaxine (SNRI) - reuptake inhibitor of NE
