Dr. Ansam Sawalha, director of the Poison Control and Drug Information Center (PCDIC), gave a talk about the negative health effects of addictive substance and the role of youth in combating this problem.  The talk was organized by An-Najah's Student Union in collaboration with the Friends of Life society, and it was attended by a large number of interested personnel and students.In her talk, Dr. Sawalha, mentioned the types of addictive substances and their classification based of their effects on the body such as stimulants, sedatives, hallucinogens, and others.  The talk also included the negative effects of addictive substance on the circulatory system, central nervous system (such as seizures, stroke, early dementia), respiratory system (pulmonary edema, bronchospasm, and pneumonia), effect on the eye (decrease vision acuity, cataracts), effects on the liver (yellowish skin, itching, damage of liver cells, hepatitis B and C), and effects on kidneys (edema, inflammation of kidney tissue). The relation between drugs of abuse and AIDS was clarified during Dr. Sawalha’s lecture.  In addition, the effect of smoking on the human body was explained.  "Cigarettes are not among drugs of abuse but are addictive and negatively affect our health, and many believe that it is the first step toward addiction," Dr. Sawalha noted.  She indicated that PCDIC is deeply concerned about the problem of addiction and is always ready to help in treating or preventing it.  Dr. Sawalha said that the PCDIC welcomes student volunteers to work on this aspect and to spread knowledge regarding such chemicals specially that prevention is much better than treatment.