What is kush? Warning over highly addictive and affordable cannabis taking over the world - leaving teens unable to walk

The drug, taken mostly by men aged 18 to 25, causes people to fall asleep while walking, to fall over, to bang their heads against hard surfaces and to walk into moving traffic. Kush should not be confused with the drug of the same name found in the US, which is a mixture of “an ever-changing host of chemicals” sprayed on plant matter and smoked.

Kush in Sierra Leone is quite different. It is a mixture of cannabis, fentanyl, tramadol, formaldehyde and – according to some – ground down humans bones.

It is mixed by local criminal gangs, but the constituent drugs have international sources, facilitated no doubt by the internet and digital communications. Kush has shaken this part of West Africa to its core - not just Sierra Leone but also Liberia, Guinea, Guinea-Bissau and the Gambia. It is highly addictive, ever-evolving and affordable.

The sprayed grey-green marshmallow leaves are rolled in a joint like marijuana and are extremely dangerous. Samples of the drug tested by researchers contained nitazens, one of the deadliest synthetic drugs in the world.

According to Sky News, the shocking effects of the drug can be seen on the bodies of young men and women around Freetown where there are teenagers with sores eating away at their legs, unable to walk. Mothers who smoked during pregnancy carrying sickly rash-covered infants.

While cannabis is widely grown in Sierra Leone, the fentanyl is thought to originate in clandestine laboratories in China where the drug is manufactured illegally and shipped to west Africa. Tramadol has a similar source, namely illegal laboratories across Asia. Formaldehyde, which can cause hallucinations, is also reported in this mixture.

Kush costs around five leones (20 UK pence) per joint, which may be used by two or three people, with up to 40 joints being consumed in a day. This represents a massive spend on drugs and illustrates the addictive nature of the mixture, in a country where the annual income per capita is around £500.