ADHD and Addiction Flashcards
• Attention-deficit/hyperactivity disorder (ADHD) DSM-IV diagnosis
• Attention-deficit/hyperactivity disorder (ADHD) DSM-IV diagnosis = 6/9 inattention symptoms, and 6/9 hyperactivity/impulsivity symptoms 6 for months.
ADHD affects how many kids?
- ≈ 8% of kids.
* ≈ > 2 * more likely in boys.
what did • Jensen et al. (2001) do
found ADHD is comorbid with aggression, conduct disorder, oppositional defiant disorder (ODD), depression and anxiety, and tics.
in ADHD, concordence rates are higher for ….
concordence rates are higher for MZ than DZ twins indicating genetic component
what is Functional impulsivity
Risk taking may be selected by evolution
what did Dickman 1990 do
created a funcitonal impulsivity questionnaire
medication for ADHD
Medication – Methylphenidate (trade name e.g. Ritalin)
how does Methylphenidate (trade name e.g. Ritalin) work
- Methylphenidate blocks the dopamine and noradrenalin reuptake transporter increasing dopamine in the synaptic cleft
- Amphetamine and cocaine do the same.
• Childhood ADHD = reduced activation of the ????? and ?????
• Childhood ADHD = reduced activation of the ventral attentional stream (‘what’)(hierarchically organised), and frontoparietal cortex (executive control/working memory).
• High risk children of addicted parents had …
• High risk children of addicted parents had higher anxiety, depression and ‘dysregulation’ (ADHD symptoms + cognitive impairment) at both age points.
what did Tarter 2003 do
- Combined affective+dysregulation score at age 10-12 (black bars) prospectively predicted an earlier age of initiating drug use reported at age 16.
- Early onset drug use is a risk factor for adult addiction.
- Higher depression and anxiety at age 10
- Predicted early onset of drug use
what did Wise et al 2002 do
- Drug hijack brain reward mechanisms.
- Electrical self-stimulation of the mesolimbic dopamine pathway creates ‘addictive’ like behaviour
- Electrode in rats head.
- Rats quickly acquire the response.
- Shows binge ‘consumption’.
- Displaces food till starvation.
- Continues despite painful foot shock.
what did Talwar et al. 2002 do
Rewarding rats with mesolimbic dopamine pathway stimulation for moving in a particular direction in response to virtual whisker stimulation, achieves an incredible level of control over the rats’ movement.
what did Kolb & Himmelsbach find
- Reduction of aversive states by the drug reinforces continued drug use.
- Think of pain killers. Drugs are addictive because they remove either withdrawal symptoms or psychological distress stemming from comorbid psychiatric illness.
• Methamphetamine abusers show loss of ……………………..at 1 month abstinence
• Methamphetamine abusers show loss of striatal dopamine activity (in PET) at 1 month abstinence