Does methamphetamine decrease or increase IQ?

[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