Curbs on so-called legal highs led to a drop in the number of people needing hospital treatment, a new study suggests.

NHS Lothian hospital admissions related to the drugs dropped by around 80% after they were removed from shops in Edinburgh.

However, there was also a slight increase in people seeking hospital treatment after taking more traditional drugs like ecstasy and speed.

There was no increase in admissions relating to opioids like heroin.

The research was carried out by a team at the University of Edinburgh.

Professor of clinical toxicology Michael Eddleston said: "Widespread adoption of Trading Standards enforcement, together with focused legislation, seemed to turn the tide against these highly-damaging drugs.

"These restrictions may have offered health benefits and saved the NHS substantial funds each year."

Legal highs - officially known as new psychoactive substances - were banned temporarily in 2015 and then permanently restricted by Trading Standards.