BOSTON — It makes you feel alert and happy. It makes you talkative and it's a green leaf.

So why is the Dutch government banning khat?

Because prolonged chewing of its leaves and twigs can lead to psychosis.

The Dutch government announced Wednesday that it will ban the use of the khat, a mild narcotic, according to the BBC.

Khat (catha edulis) is a leaf that when chewed releases juices that act as natural stimulant. It is widely and wildly popular across the Horn of Africa, especially in Somalia.

The Netherlands' Schipol Airport is a hub to transport khat imported from the Horn of Africa to other European countries. It is not known if another European airport will take over as the transport hub for the European khat trade. Last year khat worth about $18 million was imported to Holland, alone.

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There are concerns that the drug can cause psychosis or trigger on schizophrenia.

The Netherlands traditionally has a liberal approach to soft drugs. But the Dutch government cited noise, litter and the perceived public threat posed by men who chew khat as some of the reasons for outlawing the drug.

"I'm involved in the ban because it appears to cause serious problems, particularly in the Somali community," Dutch immigration minister Gerd Leers is quoted as saying by Radio Netherlands.

He said that 10 percent of Somali men in the Netherlands were badly affected by the drug.

"They are lethargic and refuse to co-operate with the government or take responsibility for themselves or their families," he said.

Some critics of the Dutch government allege that the ban on khat is actually a swipe at the Somali immigrants, who are largely Muslim.

Very few Dutch nationals use the drug, which is mainly chewed by people from Somalia, Ethiopia, Kenya and Yemen.

More than 25,000 Somalis now live in Holland and as the population has grown, so has the chewing of khat leaves.

Right now khat is legally imported through Amsterdam's Schiphol Airport four times a week. Khat leaves need to be fresh, or they lose their potency.

There are many reasons why khat is so popular. Users feel more alert and happy and they become more talkative. Khat suppresses the appetite.

However, heavy use can lead to insomnia, high blood pressure, heart problems and impotence, according to the Talk To Frank, a website about drugs. There is a longer-term risk of mouth cancers. Prolonged use can also create feelings of anxiety and aggression, and cause paranoid and psychotic reactions. Khat can also exacerbate pre-existing mental health problems.

The use of the stimulant is banned in the US, Canada and several other European countries.

But it is still available in the UK where it is legally sold in a small number of grocery stores.