In the programme, Selma talks to community and youth workers in Butetown, who raise their concerns about the excessive use of khat in their community.

Khat has been chewed in countries like Yemen and Somalia for centuries. Within normal social boundaries, there is little evidence to show that it has lasting damage.

However there is evidence to show that excessive and repetitive use may cause psychological harm.

She struggles to find a khat chewer who will talk openly to her, but eventually finds herself outside a 'mafresh' - a place where people go to socialise and chew khat together.

It is here, that she hears the story of a young man who chews every night for ten hours.

The programme also features Dr Tim Williams, who was involved in the last Advisory Council for the Misuse of Drugs review of khat in 2005.

Khat is now being reviewed again by the ACMD. They will report their findings later this year.