A method of treating or preventing depressed mood is described, such as for treating or preventing postpartum blues or depression or other conditions associated with increased MAO-A levels. The method comprises administering to a subject an antioxidant source at least once between day-1 to day-5 postpartum (or on treatment days 1 to 5 of a non-postpartum regimen); an optional tryptophan composition on the evening of day-3 to day-5, simultaneously or following the antioxidant source; and a tyrosine composition the day after administering the tryptophan composition, for example on day-5.