AEROBIC EXERCISE REDUCES DEPRESSIVE SYMPTOMS IN OLD
WOMEN WITH MINOR DEPRESSION BUT TRAINING FREQUENCY
MATTERS.
Legrand, F. D.1
1
Laboratoire de Psychologie Appliquée, EA4298, Université de Reims, France.
Introduction
Considerable research has pointed to the fact that depressive disorders of moderate intensity are common in old
age. For example, Pahkala, Kesti, Köngäs-Saviaro, Laippala and Kivelä (1995) reported that 8% to 16% of older
persons have clinically significant depressive symptoms not meeting the criteria of major depression in Finland.
Unfortunately, the positive effects of antidepressant medications typically are limited in this population (Oxman
& Sengupta, 2002; Williams et al., 2000), so that there is an urgent need to develop alternative treatments.
In recent years, accumulating evidence has supported the popular belief that physical activity is associated with
psychological health in the elderly. With regard to depression in particular, numerous studies (cross-sectional
studies as well as randomized controlled trials) have shown that exercise was effective in treating mild to
moderate depression (for review, see Sjösten & Kivelä, 2006). A dose-response relationship is plausible since
some authors noted that a moderate exercise dose (i.e., an energy expenditure of 17.5 kcal/kg/week) alleviates
depressive symptoms whereas a low exercise dose (i.e., 7.0 kcal/kg/week) does not (Dunn, Trivedi, Kampert,
Clark, & Chambliss, 2005). But surprisingly, frequency of training has received only little attention to date. Yet,
exercising frequently is likely to be of crucial importance for improving mood on a day-to-day basis in people
with symptoms of depression. Indeed, acute exercise has consistently been found to improve mood and positive
affect (e.g., Yeung, 1996; Reed & Ones, 2006) and, as suggested by Haskell (1987), many of the psychological
benefits of chronic exercise (including alleviation of depressive symptoms) may be attributable to the cumulative
effects of individual bouts of exercise. However this mood enhancement effect usually is short-lived and
evaporates within 4 hrs of ending an exercise session (Petruzzello & Landers, 1994; Thayer, 1996). Thus, if
reestablishing and maintaining an enhanced mood in persons with depression is the major goal, exercising on a
frequent basis should be encouraged.
Using scores from the 30-item Geriatric Depression Scale (GDS, Yesavage, 1988), the purpose of the present
study was to test whether there was a relation between exercise frequency (1 training session/week vs. 3-5
training sessions/week) and reduction in GDS score after 4 weeks of moderate exercise (walking at a self-chosen
pace for one hour).
Specifically, it was anticipated that there would be a greater mean decline in depression for those participants
who exercised 3-5 times/week because frequent participation should consistently reestablish enhanced mood
state throughout the study duration.
Methods
Participants
This research sample consisted in 21 women (Mage = 69.3 ± 3.7 yrs) recruited from two retirement centers in the
region of Champagne-Ardennes (France). All participants met the following inclusion criteria: (a) mild
depression defined as a GDS score ranging from 10 to 19; (b) not actively engaging in exercise for the preceding
6 months; and (c) between the age of 65 and 74 years (i.e., young-old persons). Exclusion criteria at screening
included: (a) treatment for major depression within the past 3 years; (b) severe depressive symptoms defined as a
GDS score higher than 20; (c) current participation in another medical intervention study, and (d) inability to
speak or read French. Eligible participants were randomly allocated to one of two groups who exercised either 35 times a week (G3-5; n = 11), or only once a week (G1; n = 10) for a total duration of 4 weeks.
Instruments
The primary outcome measure was the change in the Geriatric Depression Scale score (GDS, Yesavage, 1988)
from baseline to 6 weeks. The French version of this scale (Bourque, Blanchard, & Vézina, 1990) was used in
the present sudy, and appeared to be a reliable measure of depression (Cronbach’s alpha coefficient= .87).
Procedure and description of the treatments
After a 3-month period of on-site advertisement, 64 residents volunteered for this study. Each volunteer was
then seen individually for preliminary screening tests, baseline assessment, and completion of an informed
consent form. When this was completed and the participants were deemed eligible, they were randomized into
one of the two exercise treatments. The week following these face-to-face interviews, 24 participants (12 in each
group) underwent their assigned 4 week-long exercise training program by walking at self-selected pace for sixty
minutes once a week (G1), or between 3 to 5 days a week (G3-5). The walking sessions were organized outdoors
(on a tree-lined footpath located in the ‘Montagne de Reims’ regional park) on days when weather and ground
conditions were similar (no rain, dry ground). In both groups, all the participants exercised under the supervision
of the first author. At the end of this program, participants rated their depressive symptoms again.
Results
Twenty-four participants were enrolled and randomized (12 in each group) but three did not complete the study:
one participant was not compliant with attending the exercise sessions (G3-5) and two (in G1) caught a gastric flu
so that they were dropped just before the second week of their exercise program.
The mean scores of the Geriatric Depression Scale before and after the programmed group-exercise training are
recorded in Table 1 for each group.
Table 1. Depression scores at recruitment and at the end of the study for the two exercise groups
before
(mean ± SD)
after
(mean ± SD)
score change
(mean ± SD)
P value
95% CI
15.00 ± 2.87
12.80 ± 3.01
-2.20 ± 1.81
<.005
-3.50−-.90
14.72 ± 2.97
10.09 ± 2.07
-4.64 ± 2.98
<.001
-6.63−-2.64
G1 (n=10)
GDS
G3-5 (n=11)
GDS
The 2 x 2 mixed ANOVA for the GDS total score revealed no group effect (F(1, 19) = 1.94, p > .15), but a
significant main effect of time (F(1, 19) = 39.37, p < .005, r = .82) and, what’s most interesting, a significant
time x group interaction (F(1, 19) = 5.00, p < .05, r = .46).
Post hoc independent Student’s t-tests showed that the ratings of depression severity were not statistically
different between the two groups on admission (t(19) = 0.21, p > 0.80), but reached significance at the
termination of the exercise treatment (t(19) = 2.42, p = 0.03, r = .48). Matched-paired t-tests indicated lower
levels of depressive symptoms at post-test for both groups (for G1: t(9) = 3.84, p < .005, r = .79; and for G3-5:
t(10) = 5.17, p < .001, r = .85). However, participants who exercised frequently experienced a significantly more
important reduction in depressive symptoms (mean GDS score change = 4.6 points) than did the participants
who exercised only once a week (mean GDS score change = 2.2 points).
Finally, at the end of the exercise program, the porportion of participants reporting a GDS score lesser than 10
(i.e., indicating the near absence of any depressive symptoms) was about threefold more important in
participants from G3-5 (i.e., 27.3 %) than in those from G1 (i.e., 10%).
Discussion/Conclusions
This experiment was designed to compare the effect of frequent and infrequent aerobic exercise on depressive
symptoms in older individuals with mild to moderate depression. A first original finding is that 4 weeks of
frequent or infrequent aerobic exercise significantly lowered the intensity of depressive symptoms as measured
by the Geriatric Depression Scale. Although previous research (e.g., Chou et al., 2004; Mather et al., 2002) has
already offered support for the use of exercise prescription for the alleviation of depressive symptoms in the
elderly, this mostly applied to aged populations with clinical depression. Actually, only a few studies have been
conducted on older participants not suffering from clinical depression or from a high amount of depressive
symptoms to date. About one half of these studies provided no evidence for a positive effect of exercise (e.g.,
Chin A Paw, van Poppel, Twisk, & van Mechelen, 2004); and among those who identified exercise to have a
significant antidepressant impact, the usual length of training programs was much more longer (i.e., 16 weeks or
more) (e.g., Blumenthal, Emery, & Madden, 1989; McMurdo & Burnett, 1992).
Another original point, which confirmed our research hypothesis, is the observation that frequent exercise was
associated with more pronounced antidepressant effects than infrequent exercise.
The onset of antidepressant effects is an important issue since patients and those treating them want and need to
know when to expect the beginning of improvement. So, the finding that older individuals with mild to moderate
symptoms of depression benefit from a quite short program of aerobic exercise (i.e., 4 weeks) is of clinical
relevance. This is especially true when considering the fact that (1) the time course of pharmacologic treatments
can require several weeks (up to several months) before providing significant relief of depressive symptoms
(e.g., Ferrier, 1999), and (2) some randomized controlled trials focusing on older patients with mild depression
concluded that antidepressant medication or depression-specific counseling methods only have a relatively
modest benefit (Oxman & Sengupta, 2002; Williams et al., 2000).
Although we have demonstrated that a 4 wk-long aerobic exercise training program lessens depressive
symptoms in young-old women, the source of this effect remains to be determined. Our hypothesis was that
exercise temporarily makes people feel good, and that if a person wishes to recapture the acute mood
improvements obtained from exercise, he or she will have to exercise again. Thus, the benefits derived from
repeated bouts of exercise, if performed on a consistent basis, were thought to be the most effective means to
assist persons with mild to moderate depression to cope with their chronic psychological distress. However,
exercise-induced mood changes were not assessed in this study so that we have no empirical data available to
support (or contradict) this assumption. It is not untenable that other mechanisms account for why participants in
the high-frequency training group were those who reported the most important decrease in depression (e.g.,
distraction, camaraderie). Another limitation is that our study was done with only women. Whether or not our
results will generalize to a population of both men and women is unknown
References
Blumenthal, J. A., Emery, C. F., & Madden, D. J. (1989). Cardiovascular and behavioral effects of aerobic
exercise training in healthy older men and women. The Journals of Gerontology Series A Biological Sciences &
Medical Sciences, 44, M147-M157.
Bourque, P., Blanchard, L., & Vézina, J. (1990). Etude psychométrique de l’échelle de dépression gériatrique.
Revue Canadienne du Vieillissement, 15, 183-197.
Chin A Paw, M. J. M., vanPoppel, M. N. M., Twisk, J. W. R., & van Mechelen, W. (2004). Effects of resistance
and all-round, functional training on quality of life, vitality and depression of older adults living in long-term
care facilities. A randomized controlled trial. BMC Geriatrics, 4, 5.
Chou, K. L., Lee, P. W. H., Yu, E. C. S., Yeung-Hung Chen, D. M., Chan, S. S. C., & Chi, I. (2004). Effects of
Tai Chi on depressive symptoms amongst Chinese older patients with depressive disorders: a randomized
clinical trial. International Journal of Geriatric Psychiatry, 19, 1105-1107.
Dunn, A. L., Trivedi, M. H., Kampert, J. B., Clark, C. G., & Chambliss, H. O. (2005). Exercise treatment for
depression: efficacy and dose response. American Journal of Preventive Medicine, 28, 1-8.
Ferrier, I. N., (1999). Treatment of major depression: is improvement enough ? Journal of Clinical Psychiatry,
60, 10-14.
Haskell, W. L. (1987). Developing an activity plan for improving health. In W. P. Morgan & S. E. Goldstein
(Eds.), Exercise and mental health (pp. 37-55). Washington, DC: Hemisphere.
Marquez, D. X., McAuley, E., Motl, R. W., Elavsky, S., Konopack, J. F., Jerome, G. J., & Kramer, A. F. (2006).
Validation of Geriatric Depression scale (GDS-5) among sedentary older adults. Educational & Psychological
Measurement, 66(4), 667-675.
Mather, A. S., Rodriguez, C., Guthrie, M. F., McHarg, A. M., Reid, I. C., & McMurdo, M. E. (2002). Effects of
exercise on depressive symptoms in older adults with poorly responsive depressive disorder: randomized
controlled trial. British Journal of Psychiatry, 180, 411-415.
McMurdo, M. E. T., & Burnett, L. (1992). Randomized controlled trial of exercise in the elderly. Gerontology,
38, 292-298.
Oxman, T. E., & Sengupta, A. (2002). Treatment of minor depression. American Journal of Geriatry &
Psychiatry, 10(3), 256-264.
Pahkala, K., Kesti, K., Köngäs-Saviaro, P., Laippala, P., & Kivelä, S. L. (1995). Prevalence of depression in an
aged population in Finland. Social Psychiatry & Psychiatric Epidemiology, 30, 99-106.
Petruzzello, S. J., & Landers, D. M. (1994). Varying the duration of acute exercise: implications for changes in
affect. Anxiety, Stress & Coping, 6, 301-310.
Reed, J., & Ones, D. S. (2006). The effect of acute aerobic exercise on positive activated affect: a meta-analysis.
Psychology of Sport & Exercise, 7, 477-514.
Sjösten, N., & Kivelä, S. L. (2006). The effects of physical exercise on depressive symptoms among the aged: a
systematic review. International Journal of Geriatric Psychiatry, 21, 410-418.
Thayer, R. E. (1996). The origin of everyday moods: managing energy, tension, and stress. New York: Oxford
University Press.
Williams, J. W., Barrett, J., Oxman, T., Frank, E., Katon, W., Sullivan, M., Cornell, J., & Sengupta, A. (2000).
Treatment of dysthymia and minor depression in primary care: a randomized controlled trial in older aduls.
Journal of the American Medical Association, 284, 1519-1526.
Yesavage, J. A. (1988). Geriatric depression scale. Psychopharmacology Bulletin, 24(4), 709-711.
Yeung, R. R. (1996). The acute effects of exercise on mood state. Journal of Psychosomatic Research, 40, 123141.