Letter: Ecstasy research

Sir: The research in your article "Proof positive. Taking ecstasy permanently alters your brain" (6 November) proves no such thing. What it shows is that taking illegally procured "pills" causes changes in the brain. Because Ecstasy is illegal, the content of illegal pills is hardly ever MDMA, the substance which clubbers seek.

So, if this research was conducted on real life clubbers, it certainly cannot be concluded that MDMA causes any such effect. Illegal pills are often related chemicals, such as MDEA or MDA or cocktails of these and other drugs. No conclusions can be drawn about the health effects of using dance drugs whilst they remain illegal.

DEREK WILLIAMS

Norwich