Psychedelic drugs like LSD and ecstasy ingredient MDMA have been shown to stimulate the growth of new branches and connections between brain cells which could help address conditions like depression and addiction.

Researchers in California have demonstrated these substances, banned as illicit drugs in many countries, are capable of rewiring parts of the brain in a way that lasts well beyond the drugs' effects.

This means psychedelics could be the "next generation" of treatments for mental health disorders which could be more effective and safer than existing options, the study's authors from the University of California.