Assessed self-reported and observer-rated signs and symptoms of nicotine withdrawal precessation and 2, 7, 14, 30, 90, and 180 days postcessation in smokers who quit on their own for 30 days. Anxiety, difficulty concentrating, hunger, irritability, restlessness, and weight gain increased; heart rate decreased postcessation. Postcessation depression, but not other withdrawal symptoms, craving, or weight gain, predicted relapse. (Author/NB)