Comprehensive medical records of 45 amyotrophic lateral sclerosis (ALS) patients and 90 controls from the same community, matched by age, gender, and period of observation, were reviewed. Three (13%) of 23 men with ALS, 15 (33%) of 46 control men, 10 (45%) of 22 women with ALS, and 19 (43%) of 44 control women had antecedent psychologic or adaptational difficulties. The proportions of long-standing or serious conditions were comparable in all four groups. However, no man in whom ALS developed had a record of mild antecedent difficulties alone, whereas 3 would have been expected (p = 0.024).