Hi. On the issue of the use of Gestalt with older clients try these articles: "Reviewing the Past in the Here and Now: Using Gestalt Therapy Techniques with Life Review", by Royda Crose (1990) Journal of Mental Health Counseling, vol12, No3, p.279-287.
"Gestalt Therapy with the Elderly: On the 'Coming of Age' and 'Completing Gestalts'" by Ansel Woldt and Steven Stein (1997) Gestalt Review, vol 1, no 2, p. 163-184.
You might also try a lit search on PsychLit under Greenberg or Elliott; I can't recall, but I believe one of them has collaborated on research of the Gestalt approach with depression
Phil