Definition: A substance abuse also known as drug abuse is patterned use of material abuse (ex khat) in which one consumes the ingredient in quantities or with methods which are dangerous to themselves or others (ex. negative smoking).

 Using by mouth like Khat, drug, smoke etc.  Using by nose like (cocaine, heroin etc.)  Using by injection like morphine etc. The khat stimulant chewed used the fresh leaves and stores in the mouth, hence the word "store" to describe the consumption of khat sessions. if someone invited you to "store", know it is host to the most popular session in Yemen.

Khat has many names. Among these are Kat, Qat, Ghat and Chat, three other traditional terms for the plant in its common regions of the Horn of Africa and the Arabian Peninsula. Khat is also known as Arabian tea in the West. In the African Great Lakes region, where Catha edulis is in some areas nurtured, it is known as Miraa. In South Africa, the plant is recognized as Bushman's tea.

The consumption of khat in Yemen episode that revolves most conversations Yemenis around, it is the phenomenon unique that characterize the people of Yemen from the other peoples of the world, despite the fact that the price of leaves of this plant is expensive, the demand steadily for the leaves increase inside Yemen. It has a lot of negative effects on health, money, and society etc. In general, we demand it continues to increase, so has become a popular tradition practiced by both sexes and various ages. khat effect on the most students values ​​stored, such as some of the religious values ​​such as prayer and some acts of worship in the month of Ramadan and some moral values.

Most of the people chewing khat think that it provides them with an active mind and muscle and believe that it has health benefits, while, doctors and specialists just thinks the opposite. The experts have conducted experiments in research laboratories to determine the impact of chemicals in khat. These experiments showed that the chemicals found in the khat plant lead to a state of revelry for 24 hours after the dose, and then followed by a state of inactivity. They found that these chemicals work a little like amphetamines as it works to stimulate the nerve cells, which reduces fatigue and stress in the early hours of abuse followed by a feeling of laziness, anxiety and depression. It also agreed on research studies that khat addiction leads to many physical and psychological diseases that have some effects

The tree of khat is slow growing its high between one to five yards its usually grow on the south boundary area of the red see. The type of khat that is used is the fresh leave by chewing and keeping it in the mouth. The khat chewers experience a sense of increased energy levels, increased alertness and capacity to concentrate, development in self-confidence and an increase in libido. The khat chewing is not prohibited for male and female in Yemen. It has been estimated that about 80% of Yemeni men and 60% of women chew khat.

This study aims to understand the causes and risks of khat addiction among male students in primary and secondary schools in the Republic of Yemen. To address this phenomenon we can answer the following questions: 1. What are the reasons for the spread of qat chewing among male teenagers in Yemen? 2. Is chewing qat affects educational attainment? 3. Is there any effect for Khat chewing?

1. To determine the harm of khat chewing in health. 2. To discover the effect of khat chewing on the behavior of the students in schools.

Nurr, D., King, L. A., Saulsbury, W. and Blakemore,C. (2007) Development of a rational scale to assess the harm of drugs of potential misuse, Health Policy, Vol 369. Brooke, C., (1960) Khat (Catha Edulis): Its Production and Trade in the Middle East, The Geographical Journal, Vol. 126, No. 1, pp Ageely, H. M.,(2009) Prevalence of Khat chewing in college and secondary (high) school students of Jazan region, Saudi Arabia. Harm Reduction Journa, 6:11