Can the use of speed (amphetamine) damage your brain?
In animal experiments, amphetamine has been shown to cause brain damage. However, this has not been demonstrated in humans. Several studies show that people who use amphetamines have impaired functions such as memory, concentration and attention and decision-making. The problem is that these people have often also used other substances and it is therefore difficult to say whether this is only due to the use of amphetamine. It is also still unclear whether this recovers if you have stopped for a longer period of time.
According to various researchers, the brain damage attributed to MDMA is partly determined by combination with amphetamine use. In any case, it seems that the use of amphetamine increases the risk of brain damage. More and more research is appearing that makes this plausible.