Thinking blocks and decision problems in ADHD - Neurophysiological correlates
Thinking blocks occur equally in ADHD-HI and ADHD-I. Contrary to an earlier opinion, they are not subtype-specific. Decision-making problems, on the other hand, seem to occur much more frequently in ADHD-I than in ADHD.
This suggests that the two manifestations have different neurophysiological correlates.
Extremely elevated norepinephrine levels during severe stress impair the functionality of the PFC. While slightly elevated norepinephrine levels increase thinking ability, very high norepinephrine levels decrease it and behavioral control is transferred from the PFC to the posterior cortex.1234
The details of this can be found in the article ⇒ Neurotransmitters during stress In the section ⇒ Severe stress = severe NE/DA and cortisol elevation = decreased cognitive performance.
Ramos, Arnsten (2007): Adrenergic pharmacology and cognition: focus on the prefrontal cortex. Pharmacol Ther. 2007 Mar; 113(3):523-36., Kapitel 6 ↥
Birnbaum, Gobeske, Auerbach, Taylor, Arnsten (1999): A role for norepinephrine in stress-induced cognitive deficits: α-1-adrenoceptor mediation in prefrontal cortex. Biol. Psychiatry 46, 1266–1274. ↥
Ramos, Colgan, Nou, Ovadia, Wilson, Arnsten (2005). The beta-1 adrenergic antagonist, betaxolol, improves working memory performance in rats and monkeys. Biol. Psychiatry 58, 894–900. ↥
ähnlich: Arnsten (2000): Stress impairs prefrontal cortical function in rats and monkeys: role of dopamine D1 and norepinephrine alpha-1 receptor mechanisms. Prog Brain Res. 2000;126:183-92. ↥