ADHD Flashcards
examples of psychostimulants
Include: cocaine, amphetamine, methamphetamine (look like dopamine so block the transporters).
action of psychostimulants
Block or reverse monoamine transporters (Massive increase in synaptic concentration)
presentation of the action of psychostimulants
Alertness, euphoria, bruxism, weight loss.
overdose of psychostimulants
- Psychosis, Cardiac effects, Stroke (vasoconstriction), Seizures
- Treated with Haloperidol
“Withdrawal” results in ravenous appetite, exhaustion, and mental depression
GENERAL PROPERTIES OF STIMULANT DRUGS:
Increased: Arousal, attention, vigilance, movement, wakefulness, confidence
Euphoria, stress and anxiety, appetite suppression, addiction?
METHYLPHENIDATE (RITALIN): mechanisms
Similar mechanism of action to Amphetamine, Cocaine etc.
- Less potent
- Slower acting (especially in clinical preparations)
- Blocks transporters (not reverse)
- No effect on serotonin
Abused recreationally
Less addictive? (Difficult to obtain reliable data)
atomoxetine mechanisms
Blocks only the noradrenaline transporter (Increase attention)
Not addictive
- (No dopamine action?)
- Not scheduled
- (Prescription-only)
Not a cognitive enhancer in healthy individuals (?) (Limited abuse potential)
Guanfacine
Directly stimulates adrenergic receptors.
caffeine action
Blocks adenosine receptors (Adenosine normally produce ‘sleepiness’). Indirectly results in increased noradrenaline release (Mechanism unclear). Very legal.
ADHD prevalence and challenges
Restless, impulsive, difficulty concentrating (Age inappropriate)
- 7% worldwide
Problems with Response Inhibition
The ability “to resist internal or external interferences to achieve goal directed behaviours” (Barkley 1997)
Challenges with Working Memory
- Visuospatial more than verbal
- Improves with age
- Improved by methylphenidate
Response Inhibition causes, or is caused by, working memory problems?
Neurobiology poorly understood
3 types of ADHD
ADHD-PI
ADHD-PHI
ADHD-C
ADHD-PI
Formerly known as Attention Deficit Disorder (ADD)
- ‘Predominantly Inattentive’
- Difficulty maintaining focus
- Difficulty following instructions
- Easily distracted
- Forgetful
- ‘Doesn’t listen’
ADHD-PHI
- Predominantly Hyperactive-Impulsive Presentation
- Restless, interrupt others
- Excessive fidgeting or tapping
- Very talkative
- Difficulty remaining seated
ADHD-C
- Combined Presentation
- Most common type
- Mixture of both presentations (6 or more symptoms from each type)
EBP
The conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients (Sackett et al., 1996).
Cochrane: Reviews of research for evidence for a range of clinical presentations.
NICE guidance: Clinical guidelines for treatment pathways.
