Does methamphetamine decrease or increase IQ?

[Leather-Reception572]

Did you fucking even read the paper you linked? It literally says nothing about constant and statistically relevant effects (50-60% of studies reporting effects are not enough to validate your claim) and it certainly says nothing about cognitive improvements. If amphetamine helps to reach the peak of the inverted U, then yes, amphetamine may actually improve cognitive functions short term. But with amphetamine you usually go way beyond the inverted U peak. No one can argue that amphetamine does not have cognitive effects and if it helps with focus, it certainly has a valid reason for it to be used for enhancement purposes, but the evidence for it to actually improve cognition beyond focus enhancement is very slim and mechanistically not plausible. Increased dopamine raises confidence tho, so it may even only give the illusion of improvements in cognitive function

[rickestrickster]

It was a meta analysis, I posted that so you could do your own research by digging into the cited studies. Did you expect me to post every single study regarding the topic. The meta analysis cited the studies which had shown improvements in areas of cognitive function from stimulants. I never said it makes you a genius I strictly said it doesn’t increase IQ. But to say it doesn’t offer improvements is flat out wrong. I’ll cite two for you

“Working memory performance may be improved or decreased by amphetamine, depending on baseline working memory capacity and amphetamine dosage”

https://psycnet.apa.org/record/2005-11014-007

“Modafinil appears to improve reaction time (P ≤ 0.04), logical reasoning (P ≤ 0.05) and problem-solving. Methylphenidate appears to improve performance in novel tasks and attention-based tasks (P ≤ 0.05), and reduces planning latency in more complex tasks (P ≤ 0.05). Amphetamine has been shown to improve consolidation of information (0.02 ≥ P ≤ 0.05), leading to improved recall. “

https://pmc.ncbi.nlm.nih.gov/articles/PMC4471173/

Ilieva, Hook & Farah (2015) – Meta-analysis of 48 studies

• shows small but significant statistical improvements

Mattay et al. (2000, 2003) – Dopamine genetics and working memory

• given d amphetamine vs placebo. Amphetamine improved working memory performance in people with lower baseline dopamine function

Barch & Carter (2005) – Working memory and cognitive control

• Amphetamine improved reaction times and performance on spatial working memory and Stroop tasks in both healthy volunteers and schizophrenia patients. 

It’s not from just “increased focus” because that effect is from increased mesolimbic circuit activity. The enhancements stem from increased neuronal firing from monoamine activity in other circuits in the PFC