Previous research has indicated that about a quarter of older adults who become mildly depressed will go on to become seriously depressed within a year or two. A study comparing problem-solving therapy for primary care — a seven-step approach delivered by non-mental-health professionals to help patients resolve difficulties and thus improve coping skills and confidence — with a program of dietary coaching (same number of sessions and hours), has found that elderly adults with mild symptoms of depression responded equally well to both treatments.

The study involved 244 participants, of whom 90 were African-American. Only 9% of people in each intervention went on to experience an episode of major depression, and they all had a similar reduction in depressive symptoms over the two-year study period. Both approaches were equally successful among black and white participants.

The benefit of both programs is assumed to lie in the way they give people greater perceived control over their lives.

http://www.eurekalert.org/pub_releases/2014-03/uops-lic032014.php