Yang ADHD Flashcards
Implicated systems in ADHD
-Dopamine transporter
-COMT
-Cholinergic receptors
-Cholesterol metabolism
-CNS development
-Glutamate receptors
When do ADHD symptoms typically appear
5-9 years old (generally before 12 for diagnosis)
How is ADHD diagnosed?
-Six or more symptoms must be present
-Significant impairment in two or more settings
-Symptoms documented by parent, teacher, and clinician
-Interferes with functioning and development
Symptoms of ADHD
-Inattention (does not seem to listen, easily distracted)
-hyperactivity (fidgets or squirms)
-Impulsivity (leaves seat, runs/climbs excessively)
-Possible circuity mechanism: medial prefrontal cortex control might not be fully functional
Pharmacology of methylxanthines
-Antagonize adenosine receptors
-Inhibit phosphodiesterases: increase cAMP
-Increase activity of ryanodine receptors, increasing intracellular Ca2+
Location of adenosine receptors
-Cerebral cortex
-Hippocampus
-Cerebellum
-Thalamus
-Brain stem
-Spinal cord
Effects of A1 adenosine receptors
-Gi/o-linked, pre and post synaptic; inhibitory modylation of many neurotransmitters
-CNS activation: sedation, anxiolysis, anticonvulsant activity
-Peripheral activation: Decreased heart rate
Effects of A2 adenosine receptors
-A2A - Gs linked, pre and post synaptic
-Located in cerebral vasculature and striatum: vasodilation
-Heterodimerize with A1 and D2 dopamine receptors
-A2B - Gs linked, mostly on glial cells function unknown
Effects of A3 adenosine receptors
-Gq linked, hippocampus and thalamus
-Only activated in states of excessive catabolism; e.g., seizures, hypoglycemia, stroke; not antagonized by methylxanthines
Effects of methylxanthines
-Increased alertness
-Decreased fatigue
Cocaine mechanism of action
Inhibits monoamine transporters (NE, 5-HT, DA)
When is cocaine used?
-Local anesthetic
-Highly rewarding and addictive
Mechanism of action of amphetamines
Non-selective activation of monoamines (exception MDMA which is more selective for 5-HT)
Amphetamine effects
-Wakefulness
-Alertness
-Increased ability to concentrate
-highly rewarding=abuse potential (increases with increased prescribing)
-High doses can elicit psychotic behaviors
Examples of amphetamines
-Dextroamphetamine
-Lisdexamfetamine
-Amphetamine
-Methamphetamine
-Methylphenidate
-Dexmethylphenidate
-Adderall: mixture of salts, long-acting agent
-Mydayis: mixture of amphetamine salts
