"In Somalia, chewing khat is as common as meeting for a cup of coffee or having a beer in Sweden," said Gun Adnell, head of addiction treatment in northern Stockholm, to the health services magazine Vårdguiden.
"The difference is that when you're in Sweden and find yourself in a completely new culture, struggling to find a job, a place to live and learning the language, then it's easier to slip into addiction," she added.
The clinic has been set up in Kista, just north of Stockholm.
Overuse of khat, which originally comes from the Horn of Africa, can lead to anxiety, aggressivity, and difficulties sleeping.
Health care professionals at the clinic also testified to its potentially corrosive social effect.
"I've met many women who say their husbands' khat abuse was the reason they got divorced," psychiatrist Yakoub Aw Aden Abdi told Vårdguiden.
In June, border police arrested a 41-year-old man who was trying to smuggle 340 kilogrammes of khat into Sweden from Norway.
The news agency TT reported that he was arrested because he was driving on the wrong side of the road, prompting other drivers to alert the police.
In 2010, Swedish Customs (Tullverket) seized almost 14 tonnes of khat being brought to Sweden, most of it on the Öresund Bridge connecting Sweden to Denmark.