Quick bread leavening process, agents (one or more food-grade chemicals—usually a weak acid and a weak base) are added into the dough during mixing. These agents undergo a chemical reaction to produce carbon dioxide, which increases the baked good's volume and produces a porous structure and lighter texture. Yeast breads often take hours to rise, and the resulting baked good's texture can vary greatly based on external factors such as temperature and humidity. By contrast, breads made with chemical leavening agents are relatively uniform, reliable, and quick. Usually, the resulting baked good is softer and lighter than a traditional yeast bread. Chemical
Substance dependence upon which a person has developed a dependence syndrome. When dependence has developed, cessation of substance use produces an unpleasant state, which promotes continued drug use through negative reinforcement; i.e., the drug is used to escape or avoid re-entering the associated withdrawal state. The withdrawal state may include physical-somatic symptoms (physical dependence), emotional-motivational symptoms (psychological dependence), or both. Chemical and hormonal imbalances may arise if the substance is not introduced. Psychological stress may also result if the substance is not re-introduced. Infants also suffer from substance withdrawal, known as Neonnatal Abstinence Syndrome (NAS) which has severe and life-threatening effects on