The drugs that were known as legal highs have become a global phenomenon. They have exploded in popularity in the UK, and deaths from these chemical compounds, designed to mimic illegal drugs like cocaine and cannabis, have tripled here in recent years. In May 2016, the government acted by banning these drugs with the introduction of the Psychoactive Substances Act. The north east of England is one of the worst-hit areas for drug addiction. Panorama spent six months in Newcastle to see how the city is tackling the problem and asks whether the new law is working.