We describe the case of a patient who, after a traumatic experience at the age of 12, had a series of anniversary depressive episodes at 16, 17, 18 and 19 years of age, followed by a series of anniversary manic episodes at the ages of 21,23, 24, 25 and 26 years. All of these episodes occurred almost always a few days before or after the date of the accident and only when the patient was residing in his home town, the place of the traumatic event. The case fulfills the DSM-III-R criteria for seasonal mood disorder, but differs from previously described cases in that: (a) both depressive and manic episodes developed at the same time of the year, and (b) the illness was precipitated by psychosocial factors rather than climatic conditions.