Five hundred and fifty-eight cigarette smokers were randomized in 4 groups: acupuncture, behavior therapy, placebo and waiting list. The MMPI scales showed stability across pretest, posttest and a one-year follow-up. Principal components analysis isolated a "depression-psychasthenia" factor accounting for 61% of the variance. Moreover 43% of the subjects had an abnormal MMPI profile. Segmentation isolated predictive factors: a high number of pathological MMPI scales predicted failures in any kind of treatment. Acupuncture yielded better outcomes when the profiles were normal. Behavior therapy and placebo had better outcomes when the anxiety index was abnormal. The study underscores the role of personality factors in tobacco addiction and their influence on cessation programs outcomes.