In a meta-anylysis, Bohlmeijer (2007) found that:
In the last twenty years reminiscence has been applied in a large
number of settings and with a large number of target groups. Examples
of applications are: community-residents with a major depression,
elderly with moderate depressive symptoms, nursing home residents,
elderly with dementia, rural-dwelling older adults, elderly in
assisted-living communities. ... We conducted a meta-analysis to
assess the effects of reminiscence on depression across different
modalities and target-groups. An over-all effect size of 0.84 (95% CI
= 0.31 – 1.37) was found, indicating a statistically and clinically significant effect of reminiscence and life review on depressive
symptomatology in elderly people. This effect is comparable to the
effects commonly found for pharmacotherapy and psychological
treatments. (p. 152f.)
To answer your first question, it seems that reminiscence and life review are an effective treatmtment of depression for a wide variety of (elderly) patients. It should be noted that a "significantly larger effect was found in studies in which life-review was the intervention (d=1.04) as compared to studies that used simple reminiscence (d=0.40)" (p. 152).
Several theories have been applied to try to explain how recalling memories decreases depression:
- disengagement theory
- ego-integrity theory
- continuity theory
- socio-emotional selectivity theory
Disengagement Theory
The foundations for reminiscence and life-review therapy were laid by
Butler (1963) in his famous paper The life-review: an interpretation
of reminiscence in the aged. In this paper Butler put down his
clinical observation of an increase of reminiscence – the act or
process of recalling the past - in older people and postulated that
this was due to the universal occurrence of an inner experience or
mental process of reviewing one’s life. He conceived of life-review as
a spontaneously or naturally occurring process that is ‘characterized
by the progressive return to consciousness of past experiences, and,
particularly, the resurgence of unresolved conflicts’ (Butler, 1963,
pg 66). He hypothesized that it is caused by the ‘realization of
approaching dissolution and death, and the inability to maintain one’s
sense of personal invulnerability’ (Butler, 1963, pg 67). Though he
recognized that people of all ages review their past from time to time
and that any crisis may prompt life review, Butler stressed that
life-review is more intensive and observed more frequently in (early)
old age. He discerned adaptive and constructive manifestations of
life-review from psychopathological manifestations. The adaptive
variant is described as a reconsideration of former life-experiences
and their meanings. It will often be accompanied by mild feelings of
nostalgia or regret but is generally typified by expanded
understanding and acceptance of one’s life, the experience of
meaningfulness and declining death-anxiety. (Bohlmeijer, 2007, p.
32)
Ego-Integrity Theory
In its early stages reminiscence was studied mainly within the context
of developmental stage theory (Erikson, 1963; Webster, 1999).
Life-review was seen as a naturally occurring process which takes
place in the last stage of the psychosocial development of human
beings. The main hypotheses that could be deduced from this theory
were that life-review is universal and old-age specific. These
hypotheses were not confirmed in empirical studies. ... Based on
studies rejecting the claim that life-review is old-age specific, it
was suggested that reminiscence and life-review could be better
understood within a life-span perspective (Webster & Cappeliez, 1993;
Webster, 1999). ...
In addition to the disengagement theory (Baum & Baum, 1980; Butler,
1963) and the ego-integrity theory (Erikson, 1956; Taft & Nehrke,
1990), in recent years new theories are applied to reminiscence, for
example the continuity theory and socio-emotional selectivity theory.
These theories fit with a contextual and life-span approach to
reminiscence. (Bohlmeijer, 2007, p. 37f., 40)
Continuity Theory
According to continuity theory individuals, when confronted with
life-events or transitions, ‘attempt to preserve and maintain existing
internal and external structures and they prefer to accomplish
this objective by using strategies tied to their past experiences of
themselves’ (Atchley, 1989, pg 137). This sense of continuity, with
the aid of reminiscence, will promote adaptation (Parker, 1999).
Continuity theory would predict that people will reminisce more
frequently during periods of personal transition than in more stable
periods. In testing this hypothesis, Parker (1999) found that young
people were significantly more likely to reminisce during transitional
periods than older adults. (Bohlmeijer, 2007, p. 40)
Socio-Emotional Selectivity Theory
Another theory applied to reminiscence is
the socio-emotional selectivity theory (Carstensen, 1995). This theory
proposes that with growing age emotion regulation becomes more
important than information gain and that the elderly arrange their
social life in such a way (concentrating on close relationships) that
they can have as many emotionally meaningful interactions as possible
(Pasupathi & Carstensen, 2003). One important aspect of such
self-regulation is known as the positivity effect (Carstensen &
Mikels, 2005), in which it is assumed that an emo- tionally gratifying
focus ‘...would bias attention and memory in favour of material that
optimizes emotion regulation (i.e., positive material) even if there
are costs to focusing only on such material’ (p. 118). This hypothesis
has been supported by many studies (Kennedy, Mather, & Carstensen,
2004).
Older adults will therefore actively look for social
interactions in which they reminisce because of the potential for
emotion regulation and well-being (Penne- baker, 1997; Bluck & Levine,
1998). This preference for talking about the past in social
interactions with strangers was confirmed in several studies
(Pasupathi & Carstensen, 2003). (Bohlmeijer, 2007, p. 41)
Note:
Bohlmeijer's dissertation gives a comprehensive overview of this area, if you want a quick introduction. It is available for free online (see link below). Serrano's article has been quoted 157 times, according to Google Scholar. Probably some of those articles will provide interesting criticism and more recent research not covered in Bohlmeijer's meta-analysis from five years ago. You can find these articles listed at Google Scholar.
Sources:
