A new method for studying the role of a critical neurotransmitter in disorders such as epilepsy, anxiety, insomnia, depression, schizophrenia, and alcohol addiction could help create safer and more efficient drugs for treating those conditions. A group of scientists led by Gong Chen, associate professor of biology at Penn State, has created the new method by molecularly engineering a model synapse--a structure through which a nerve cell sends signals to another cell.

Recovering addicts who avoid coping with stress succumb easily to substance-use cravings, making them more likely to relapse during recovery, according to behavioral researchers. "Cravings are a strong predictor of relapse," said H. Harrington Cleveland, associate professor of human development at Penn State. "Whether you avoid problems or analyze problems not only makes a big difference in your life but also has a powerful impact on someone who has worked hard to stay away from alcohol and other drugs."

A wedge of rich, dark chocolate cake iced in thick, sweet ganache beckons. Each bite melts onto the tongue, delivering a delightful rush and a feeling that all is well. Soon after the plate is empty, the mind wonders when the next piece may come along, inviting the question: Is sugar habit-forming?

In medical terms, a substance is addictive if it: