International Psychogeriatrics, Vol.3, No.I, 1991 0 1991 Springer Publishing Company
Proposed Factor Structure of the Geriatric Depression Scale Javaid I. Sheikh, M.D., Jerome A. Yesavage, M.D., John 0. Brooks 111, Ph.D., Leah Friedman, Ph.D., and Peter Gratzinger, Ph.D. Veterans Administration Medical Center, Palo Alto, California Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, U S A .
Robert D. Hill, Ph.D. Department of Psychology, University of Utah, Salt Lake City, Utah, U.S.A.
Anastasia Zadeik and Thomas Crook, Ph.D. Memory Assessment Clinics, Bethesda, Maryland, U.SA. ABSTRACT. The Geriatric Depression Scale (GDS) is commonly used to measuredepression in the elderly. However, there have been no reports of the underlyingstructureoftheGDS.Tothisend,theGDSwas administered to 326 community-dwellingelderly subjects, and the data were subjected to a factor analysis. A five-factor solution was selectedand, after a varimax rotation, the factors that emerged could be described as: (1) sad mood, (2) lack of energy, (3) positive mood, (4) agitation, and (5) social withdrawal. This solution accounted for 42.9% of the variance. Knowledge of the factor smcture should aid both clinicians and researchersin the interpretation of responses on the GDS. The Geriatric Depression Scale (GDS) was developed to avoid the problems that arise when scales developed for use with young subjects are applied to elderly subjects (Yesavage et al., 1983). One such problem relates to somatic complaints. For example, in young patients the number of somatic complaints can be a valuable indicator of depression (Bolla-Wilson & Bleecker, 1989;Zemore & Eames, 1979); in elderly patients, however, somatic complaints do not provide a useful index of depression because, in general, elderly patients tend to report somatic problems (Yesavageet al., 1983). The GDS avoids this problem by excluding from the scale questions that relate to somatic complaints. The validity of the GDS has been demonstratedin severalempiricalstudies. Brink et al. (1982) found that the GDS had an 84% sensitivity rate and a 95% specificity 23
24
J . I . Sheikh et al.
rate for detecting depression in a sample of community-dwellingelderly. In a study involving hospitalized elderly patients, Koenig, Meador, Cohen, and Blazer (1988) found the GDS to have a 92% sensitivity rate and an 89% specificity rate. Agrell and DeNin (1989), in their study of stroke patients, found the GDS to have a sensitivity of 88% and a specificity of 64%, rates that were comparableto the other depression scales they studied. The GDS has been used in a number of different research areas. It has been included as ameasure in comparativestudies of depressionscales (Agrell & Dehlin, 1989;Bolla-Wilson&Bleecker,1989;Kafoneketal., 1989;Koenigetal., 1988;and Ma@, Schifano, &deLeo, 1986),inpharmacologicstudies (Altamuraet al., 1988; Drinka& Vocks, 1987;Vida, Gauthier,& Gauthier, 1989),in nursinghome settings (Snowden & Donnelly, 1986), and in psychometric studies (Best, Davis, Morton, & Romeis, 1984; Brink, Houston, Boust, & Roccaforte, 1985; Burke et al., 1989; Cwikel & Ritchie, 1988, 1989). In fact, the GDS has been translated into 12 languages. We should emphasize, however, that no validity studies have been conducted on these translations and, as Cwikel and Ritchie (1989) suggest, caution should be exercised when using the GDS in different cultures. Despite the extensive use of the GDS in both clinical practice and research, an underlying structure of the scale has not yet been proposed. Undoubtedly, most psychiatrists would be able to place the GDS items into meaningful groups based on their knowledge of depressionin the elderly; however, a priori groupings are not necessarily correct. An empirical analysisof the structureof the scale could provide a clearer picture of the relations among the items and, because the factor structure could be subjected to further testing, its identification should facilitate research pertaining to the scale. The potential benefits of a factor analysis of the GDS are not limited to research applications. One possible use of the GDS factor structure might be to provide clinicians with a relatively rapid means of characterizing their patients’ subjective experiences of depression. For example, if one patient has a high score on a hypotheticalindecisivenessfactor and anotherpatient does not, then the first patient probably experiences more difficulty in making decisions than does the second. Naturally, such characterizationscould only be approximate and would not substitute for clinical evaluations. Additional research with the GDS factor structuremay validate the factors as a means of obtaining initial characterizations of depression that could be compared across patients.
METHOD Subjects The subjectsincluded in this study were a groupof 326 community-dwellingelderly with an age range of 66 to 92 years. The mean age was 71 (SD = 4.35). Subjects were recruited by newspaper and other media announcements.
Geriatric Depression Scale
25
Geriatric Depression Scale The Geriatric Depression Scale, which is provided in Table 1, was administered to all subjectsby trained personnel. The scoringof the GDS involves giving one point when the answer to a question is indicative of depression. For some questions a “no” answer is worth one point and for others a “yes” answer is worth one point, as noted in Table 1. Specific instructions for scoring the GDS are provided by Yesavage et al. (1983). For the purposes of our analyses, the GDS responses were translated into a binary scale on which “1” is indicative of depression and “0”is not.
RESULTS The mean GDS score for the subjects was 7.10 (SO= 5.26). Using a criterion of 11 or greater as indicative of depression (Yesavage et al., 1983),75 of the subjects were depressed and 25 1 were not. TABLE 1. Geriatric Depression Scale 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.
Are you basically satisfied with your life? Have you dropped many of your activities and interests? Do you feel that your life is empty? Do you often get bored? Are you hopeful about the future? Are you bothered by thoughts you can’t get out of your head? Are you in good spirits most of the time? Are you afraid that something bad is going to happen to you? Do you feel happy most of the time? Do you often feel helpless? Do you often get restless and fidgety? Do you prefer to stay at home, rather than going out and doing new things? Do you frequently worry about the future? Do you feel you have more problems with memory than most? Do you think it is wonderful to be alive now? Do you often feel downhearted and blue? Do you feel pretty worthless the way you are now? Do you worry a lot about the past? Do you find life very exciting? Is it hard for you to get started on new projects? Do you feel full of energy? Do you feel that your situation is hopeless? Do you think that most people are better off than you are? Do you frequently get upset over little things? Do you frequently feel like crying? Do you have trouble concentrating? Do you enjoy getting up in the morning? Do you prefer to avoid social gatherings? Is it easy for you to make decisions? Is your mind as clear as it used to be?
Note: An answer of “no” is indicative of depression for question numbers 1, 5, 7 , 9, 15, 19, 21, 27, and 30. For all other questions, an answer of “yes” indicates depression.
J . I . Sheikh et al.
26
The responses to the items were first subjected to a principal components factor analysis. Although there is a variety of methods for determining the number of factors to extract from a set of data (Gorsuch, 1983), we chose to retain five of the eight factors with eigenvalues greater than one. This factor structure, which accounts for 42.9% of the variance, yielded a more interpretable, and theoretically economical, pattern of loadings after a varimax rotation than did other solutions. The factor structure of the scale is provided in Table 2. The eigenvalues from the principal components analysis were 6.19, 1.92, 1.64, 1.46, and 1.34. After rotation, Factor 1 accounted for 11 % of the variance, Factor 2 for 9.7%. Factor 3 for 8.4%, Factor 4 for 7.3%, and Factor 5 for 6.5%.
DISCUSSION The description of factors is, of course, subjective. However, we believe that certain descriptions appear to be appropriate for each of the five factors. It is TABLE 2. Factor Loadings for the Geriatric Depression Scale Question
8. bad happen 6. thoughts 23. better off 13. worry 16. downhearted 18. past worry 10. helpless 25. crying 22. hopeless 29. decisions 20. started hard 21. energy 30. mind clear 26. concentrate 2. activities 15. alive 27. getting up 9. happy 5 . hopeful 7. good spirits 19. exciting 24. upset 11. restless 4. bored 12. stay home 28. avoid social 1. satisfied 3. life empty 14. memory 17. feel worthless
Factor 1
Factor 2
Factor 3
Factor 4
Factor 5
.63 .55 .54 .52 .52 .52 .50
.13 .15 -.03 .39 .24 -. 03 .33 '07 -.01 .59 5.7 .57 .55 .51 .54 .I2 .I3 .I3 .03 -.03 .45 -.07 .I6 .30 .18 .10 .34 .33 .15 .21
.07 -.01 I20 .05 .27 .05 .12 .03 .35 .07 .04 .26 .I0 .06
-. 15 .26 .19 .06 .33
.03
SO
.47 .I3 .16 .06 .04
.05 I22 -.02 .09 .17 .20 .42 -.04 .15 .19 .04
.I4
.oo
.35 .28 .08 .33
-.04
.71 .58 .56 .52 .51 .46 .12 .I0 -.01 -. 03 .15 .40 .08 -.02 .23
.15 .22 .08 -.08 .13 .13 -. 12 .16 .33 -. 19 -.01
-.06 .36
.os .I3 .12 .66 .61 .60 .04
.14 .16 .20 .44 .21
.oo
-. 16
-.09 .03 '19 -.08 ,023 .12 -. 15 .25 .32 .07 .09 .11 .04 -.04
-.06 .13 .02 .12 .04 .08 -.13 .80 .69 -.28 -.23 '12 .01
Note: Items considered to load on a particular factor are in boldface.
Geriatric Depression Scale
27
interesting that two of the factors tap into mood in light of the fact that affective disorders have been described as primarily disturbances of mood (Zarit, 1980). Factor 1 appears to reflect a dimension of sad mood and pessimistic outlook. Although sad mood and negative outlook for the future make sense clinically, it is not immediately obvious why the “persistentthoughts” item appears in this factor. It may well be that rumination accompanies depressed mood and pessimism. Factor 2 appears to identify a lack of “mental and physical energy.” Some “cognitive” complaints common to elderly depressives are found in this factor, such as having difficulty concentrating and lacking initiative. These complaints may be associated with depleted mental energy. The third factor appears to relate to positive or happy mood and includes an item reflecting a positive or optimistic outlook for the future. Of course, the response indicative of depression for these items would be “no” which would indicate an absence rather than a presence of positive mood or optimism. The absence of a positive mood appears associated with a negative outlook on the future. Factor 4 appears to describe a core feature of agitation or restlessness. Three questionnaireitems are the major contributorsto this factor: (24) Do you frequently get upset over little things? (11) Do you often get restless and fidgety? and (4)Do you often get bored? Although there is not an apparent association among these items, they may represent different aspects of agitation. The “upset” item may tap emotional agitation,the “restless”item may tap physical agitation,and the “bored” item may tap mental agitation, which prevents the individual from getting involved or interested in various activities. Finally, Factor 5 can be described as a social withdrawal factor. This factor fits with the social withdrawal so often encountered in clinical experience with depressed patients. In conclusion, it appears that the GDS can be described with a five-factor structure which could provide a useful way of interpreting GDS scores. These factors may be helpful to researchers who are interested in investigating the predictive uses of the GDS as well as to those who would like measures that are more descriptive than a single total score.
REFERENCES Agrell, B., & Dehlin, 0. (1989). Comparison of six depression rating scales in geriatric stroke patients. Stroke, 22, 1190-1194. Altamura, A. C., Mauri, M. C.,Colacurcio, F., Scapicchio,P. L., Hadjchhstos, C., Carucci, C., Minervini, M. Montanini, R., Perini, M., et aI. (1988). Trazedone in late life depressivestates: A double-blindmulticenterstudy versus amitriptylineand mianserin. Psychopharmacology, 25 (Suppl.),34-36. Best, D.L,. Davis, S.,Morton, K., & Romeis, J. (1984). Measuring depression in the elderly: Psychometric andpsychosocial issues. Presented at the Annual Meeting of the American Gerontological Association, Houston, October. Bolla-Wilson, K., & BIeecker, M. L. (1989). Absence of depression in elderly adults. Journal of Gerontology: Psychological Sciences, 44, 53-55.
28
J . I . Sheikh et al.
Brink, T. L., Yesavage, J. A., Owen, L., Heersema, P. H., Adey, M., & Rose, T. L. (1982). Screening tests for geriatric depression. Clinical Gerontologist, I, 37-43. Brink, T. L., Curran, P., Don, M. L., Janson, E., McNulty, U., & Messina, M. (1985). Geriatric Depression Scale reliability: Order, examiner and reminiscence effects. Clinical Gerontologist, 3, 57-59. Burke,W. J., Houston, M. J., Boust, S.J., & Roccaforte, W. H. (1989).Use of the Geriatric Depression Scale in dementia of the Alzheimer type. Journal of the American Geriatric Society, 37, 856-860. Cwikel, J., & Ritchie, K. (1988). The short GDS: Evaluation in a heterogeneous multilingual population. Clinical Gerontologist, 8,63-71. Cwikel, J., & Ritchie, K. (1989). Screeningfor depression among the elderly in Israel: An assessmentof the shortGeriatricDepression Scale (S-GDS).lsraelJournal ofMedical Sciences, 25, 131-137 Drinka, P. J., & Vocks, S. K. (1987). Psychological depressive symptoms in grade 11 hypothyroidism in a nursing home. Psychiatric Research, 21, 199-204. Gorsuch, R. L. (1983). Factor analysis. Hillsdale, NJ: Lawrence Erlbaum Associates. Kafonek, S., Ettinger, W. H., Roca, R., Kittner, S., Taylor, N., & German, P. S. (1989). Instruments for screening for depression and dementia in a long-term care facility. Journal of the American Geriatric Society, 37,29-34. Koenig, H. G., Meador, K. G., Cohen, H. J., & Blazer, D. G. (1988). Self-rated depression scales and screening for major depression in the older hospitalized patient with medical illness. Journal of the American Geriatric Society, 36,699-706. Magni, G., Schifano, F., & de Leo, D. (1986). Assessment of depression in an elderly medical population. Journal of Aflective Disorders, 1 1 , 121-124. Snowden, J., & Donnelly, N. (1986). A study of depression in nursing homes. Journal of Psychiatric Research, 22,327-333. Vida, S., Gauthier, L., & Gauthier, S . (1989). Canadian collaborative study of tetrahydroaminoacridne ("HA) and lecithin treatment of Alzheimer's disease: Effect on mood. Canadian Journal of Psychiatry, 34, 165-170. Yesavage, J. A., Brink, T. L., Rose, T. L., Lum, O., Huang, V., Adey, M. B., & Leirer, V. 0. (1983) Development and validation of a geriatric depression screening scale: A preliminary report. Journal of Psychiatric Research, 22,37-49. Zarit, S. H. (1 980). Aging and mental disorder. New York: The Free Press. Zemore, R., & Eames, N. (1979). Psychic and somatic symptoms among young adults, institutionalized aged and noninstitutionalized aged. Journal of Gerontology, 34, 716-722.
Note. The GDS has been translated into Chinese, Dutch, French, German, Hebrew, Italian, Japanese, Portuguese, Rumanian, Russian, Spanish, and Yiddish. These translations are available upon request from the authors. Acknowledgment. This research was supported in part by the Medical Research Service of the Veterans Administration and the Clinical Research Center for the Study of Senile Dementias MH-40041. Offprints. Requests for offprints should be addressed to Dr. Yesavage, Professor, Stanford University School ofMedicine, Psychiatry Department, T D l l 4 , Stanford, CA 94305-5490, U.S.A.
Proposed Factor Structure of the Geriatric Depression Scale Javaid I. Sheikh, M.D., Jerome A. Yesavage, M.D., John 0. Brooks 111, Ph.D., Leah Friedman, Ph.D., and Peter Gratzinger, Ph.D. Veterans Administration Medical Center, Palo Alto, California Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, U S A .
Robert D. Hill, Ph.D. Department of Psychology, University of Utah, Salt Lake City, Utah, U.S.A.
Anastasia Zadeik and Thomas Crook, Ph.D. Memory Assessment Clinics, Bethesda, Maryland, U.SA. ABSTRACT. The Geriatric Depression Scale (GDS) is commonly used to measuredepression in the elderly. However, there have been no reports of the underlyingstructureoftheGDS.Tothisend,theGDSwas administered to 326 community-dwellingelderly subjects, and the data were subjected to a factor analysis. A five-factor solution was selectedand, after a varimax rotation, the factors that emerged could be described as: (1) sad mood, (2) lack of energy, (3) positive mood, (4) agitation, and (5) social withdrawal. This solution accounted for 42.9% of the variance. Knowledge of the factor smcture should aid both clinicians and researchersin the interpretation of responses on the GDS. The Geriatric Depression Scale (GDS) was developed to avoid the problems that arise when scales developed for use with young subjects are applied to elderly subjects (Yesavage et al., 1983). One such problem relates to somatic complaints. For example, in young patients the number of somatic complaints can be a valuable indicator of depression (Bolla-Wilson & Bleecker, 1989;Zemore & Eames, 1979); in elderly patients, however, somatic complaints do not provide a useful index of depression because, in general, elderly patients tend to report somatic problems (Yesavageet al., 1983). The GDS avoids this problem by excluding from the scale questions that relate to somatic complaints. The validity of the GDS has been demonstratedin severalempiricalstudies. Brink et al. (1982) found that the GDS had an 84% sensitivity rate and a 95% specificity 23
24
J . I . Sheikh et al.
rate for detecting depression in a sample of community-dwellingelderly. In a study involving hospitalized elderly patients, Koenig, Meador, Cohen, and Blazer (1988) found the GDS to have a 92% sensitivity rate and an 89% specificity rate. Agrell and DeNin (1989), in their study of stroke patients, found the GDS to have a sensitivity of 88% and a specificity of 64%, rates that were comparableto the other depression scales they studied. The GDS has been used in a number of different research areas. It has been included as ameasure in comparativestudies of depressionscales (Agrell & Dehlin, 1989;Bolla-Wilson&Bleecker,1989;Kafoneketal., 1989;Koenigetal., 1988;and Ma@, Schifano, &deLeo, 1986),inpharmacologicstudies (Altamuraet al., 1988; Drinka& Vocks, 1987;Vida, Gauthier,& Gauthier, 1989),in nursinghome settings (Snowden & Donnelly, 1986), and in psychometric studies (Best, Davis, Morton, & Romeis, 1984; Brink, Houston, Boust, & Roccaforte, 1985; Burke et al., 1989; Cwikel & Ritchie, 1988, 1989). In fact, the GDS has been translated into 12 languages. We should emphasize, however, that no validity studies have been conducted on these translations and, as Cwikel and Ritchie (1989) suggest, caution should be exercised when using the GDS in different cultures. Despite the extensive use of the GDS in both clinical practice and research, an underlying structure of the scale has not yet been proposed. Undoubtedly, most psychiatrists would be able to place the GDS items into meaningful groups based on their knowledge of depressionin the elderly; however, a priori groupings are not necessarily correct. An empirical analysisof the structureof the scale could provide a clearer picture of the relations among the items and, because the factor structure could be subjected to further testing, its identification should facilitate research pertaining to the scale. The potential benefits of a factor analysis of the GDS are not limited to research applications. One possible use of the GDS factor structure might be to provide clinicians with a relatively rapid means of characterizing their patients’ subjective experiences of depression. For example, if one patient has a high score on a hypotheticalindecisivenessfactor and anotherpatient does not, then the first patient probably experiences more difficulty in making decisions than does the second. Naturally, such characterizationscould only be approximate and would not substitute for clinical evaluations. Additional research with the GDS factor structuremay validate the factors as a means of obtaining initial characterizations of depression that could be compared across patients.
METHOD Subjects The subjectsincluded in this study were a groupof 326 community-dwellingelderly with an age range of 66 to 92 years. The mean age was 71 (SD = 4.35). Subjects were recruited by newspaper and other media announcements.
Geriatric Depression Scale
25
Geriatric Depression Scale The Geriatric Depression Scale, which is provided in Table 1, was administered to all subjectsby trained personnel. The scoringof the GDS involves giving one point when the answer to a question is indicative of depression. For some questions a “no” answer is worth one point and for others a “yes” answer is worth one point, as noted in Table 1. Specific instructions for scoring the GDS are provided by Yesavage et al. (1983). For the purposes of our analyses, the GDS responses were translated into a binary scale on which “1” is indicative of depression and “0”is not.
RESULTS The mean GDS score for the subjects was 7.10 (SO= 5.26). Using a criterion of 11 or greater as indicative of depression (Yesavage et al., 1983),75 of the subjects were depressed and 25 1 were not. TABLE 1. Geriatric Depression Scale 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.
Are you basically satisfied with your life? Have you dropped many of your activities and interests? Do you feel that your life is empty? Do you often get bored? Are you hopeful about the future? Are you bothered by thoughts you can’t get out of your head? Are you in good spirits most of the time? Are you afraid that something bad is going to happen to you? Do you feel happy most of the time? Do you often feel helpless? Do you often get restless and fidgety? Do you prefer to stay at home, rather than going out and doing new things? Do you frequently worry about the future? Do you feel you have more problems with memory than most? Do you think it is wonderful to be alive now? Do you often feel downhearted and blue? Do you feel pretty worthless the way you are now? Do you worry a lot about the past? Do you find life very exciting? Is it hard for you to get started on new projects? Do you feel full of energy? Do you feel that your situation is hopeless? Do you think that most people are better off than you are? Do you frequently get upset over little things? Do you frequently feel like crying? Do you have trouble concentrating? Do you enjoy getting up in the morning? Do you prefer to avoid social gatherings? Is it easy for you to make decisions? Is your mind as clear as it used to be?
Note: An answer of “no” is indicative of depression for question numbers 1, 5, 7 , 9, 15, 19, 21, 27, and 30. For all other questions, an answer of “yes” indicates depression.
J . I . Sheikh et al.
26
The responses to the items were first subjected to a principal components factor analysis. Although there is a variety of methods for determining the number of factors to extract from a set of data (Gorsuch, 1983), we chose to retain five of the eight factors with eigenvalues greater than one. This factor structure, which accounts for 42.9% of the variance, yielded a more interpretable, and theoretically economical, pattern of loadings after a varimax rotation than did other solutions. The factor structure of the scale is provided in Table 2. The eigenvalues from the principal components analysis were 6.19, 1.92, 1.64, 1.46, and 1.34. After rotation, Factor 1 accounted for 11 % of the variance, Factor 2 for 9.7%. Factor 3 for 8.4%, Factor 4 for 7.3%, and Factor 5 for 6.5%.
DISCUSSION The description of factors is, of course, subjective. However, we believe that certain descriptions appear to be appropriate for each of the five factors. It is TABLE 2. Factor Loadings for the Geriatric Depression Scale Question
8. bad happen 6. thoughts 23. better off 13. worry 16. downhearted 18. past worry 10. helpless 25. crying 22. hopeless 29. decisions 20. started hard 21. energy 30. mind clear 26. concentrate 2. activities 15. alive 27. getting up 9. happy 5 . hopeful 7. good spirits 19. exciting 24. upset 11. restless 4. bored 12. stay home 28. avoid social 1. satisfied 3. life empty 14. memory 17. feel worthless
Factor 1
Factor 2
Factor 3
Factor 4
Factor 5
.63 .55 .54 .52 .52 .52 .50
.13 .15 -.03 .39 .24 -. 03 .33 '07 -.01 .59 5.7 .57 .55 .51 .54 .I2 .I3 .I3 .03 -.03 .45 -.07 .I6 .30 .18 .10 .34 .33 .15 .21
.07 -.01 I20 .05 .27 .05 .12 .03 .35 .07 .04 .26 .I0 .06
-. 15 .26 .19 .06 .33
.03
SO
.47 .I3 .16 .06 .04
.05 I22 -.02 .09 .17 .20 .42 -.04 .15 .19 .04
.I4
.oo
.35 .28 .08 .33
-.04
.71 .58 .56 .52 .51 .46 .12 .I0 -.01 -. 03 .15 .40 .08 -.02 .23
.15 .22 .08 -.08 .13 .13 -. 12 .16 .33 -. 19 -.01
-.06 .36
.os .I3 .12 .66 .61 .60 .04
.14 .16 .20 .44 .21
.oo
-. 16
-.09 .03 '19 -.08 ,023 .12 -. 15 .25 .32 .07 .09 .11 .04 -.04
-.06 .13 .02 .12 .04 .08 -.13 .80 .69 -.28 -.23 '12 .01
Note: Items considered to load on a particular factor are in boldface.
Geriatric Depression Scale
27
interesting that two of the factors tap into mood in light of the fact that affective disorders have been described as primarily disturbances of mood (Zarit, 1980). Factor 1 appears to reflect a dimension of sad mood and pessimistic outlook. Although sad mood and negative outlook for the future make sense clinically, it is not immediately obvious why the “persistentthoughts” item appears in this factor. It may well be that rumination accompanies depressed mood and pessimism. Factor 2 appears to identify a lack of “mental and physical energy.” Some “cognitive” complaints common to elderly depressives are found in this factor, such as having difficulty concentrating and lacking initiative. These complaints may be associated with depleted mental energy. The third factor appears to relate to positive or happy mood and includes an item reflecting a positive or optimistic outlook for the future. Of course, the response indicative of depression for these items would be “no” which would indicate an absence rather than a presence of positive mood or optimism. The absence of a positive mood appears associated with a negative outlook on the future. Factor 4 appears to describe a core feature of agitation or restlessness. Three questionnaireitems are the major contributorsto this factor: (24) Do you frequently get upset over little things? (11) Do you often get restless and fidgety? and (4)Do you often get bored? Although there is not an apparent association among these items, they may represent different aspects of agitation. The “upset” item may tap emotional agitation,the “restless”item may tap physical agitation,and the “bored” item may tap mental agitation, which prevents the individual from getting involved or interested in various activities. Finally, Factor 5 can be described as a social withdrawal factor. This factor fits with the social withdrawal so often encountered in clinical experience with depressed patients. In conclusion, it appears that the GDS can be described with a five-factor structure which could provide a useful way of interpreting GDS scores. These factors may be helpful to researchers who are interested in investigating the predictive uses of the GDS as well as to those who would like measures that are more descriptive than a single total score.
REFERENCES Agrell, B., & Dehlin, 0. (1989). Comparison of six depression rating scales in geriatric stroke patients. Stroke, 22, 1190-1194. Altamura, A. C., Mauri, M. C.,Colacurcio, F., Scapicchio,P. L., Hadjchhstos, C., Carucci, C., Minervini, M. Montanini, R., Perini, M., et aI. (1988). Trazedone in late life depressivestates: A double-blindmulticenterstudy versus amitriptylineand mianserin. Psychopharmacology, 25 (Suppl.),34-36. Best, D.L,. Davis, S.,Morton, K., & Romeis, J. (1984). Measuring depression in the elderly: Psychometric andpsychosocial issues. Presented at the Annual Meeting of the American Gerontological Association, Houston, October. Bolla-Wilson, K., & BIeecker, M. L. (1989). Absence of depression in elderly adults. Journal of Gerontology: Psychological Sciences, 44, 53-55.
28
J . I . Sheikh et al.
Brink, T. L., Yesavage, J. A., Owen, L., Heersema, P. H., Adey, M., & Rose, T. L. (1982). Screening tests for geriatric depression. Clinical Gerontologist, I, 37-43. Brink, T. L., Curran, P., Don, M. L., Janson, E., McNulty, U., & Messina, M. (1985). Geriatric Depression Scale reliability: Order, examiner and reminiscence effects. Clinical Gerontologist, 3, 57-59. Burke,W. J., Houston, M. J., Boust, S.J., & Roccaforte, W. H. (1989).Use of the Geriatric Depression Scale in dementia of the Alzheimer type. Journal of the American Geriatric Society, 37, 856-860. Cwikel, J., & Ritchie, K. (1988). The short GDS: Evaluation in a heterogeneous multilingual population. Clinical Gerontologist, 8,63-71. Cwikel, J., & Ritchie, K. (1989). Screeningfor depression among the elderly in Israel: An assessmentof the shortGeriatricDepression Scale (S-GDS).lsraelJournal ofMedical Sciences, 25, 131-137 Drinka, P. J., & Vocks, S. K. (1987). Psychological depressive symptoms in grade 11 hypothyroidism in a nursing home. Psychiatric Research, 21, 199-204. Gorsuch, R. L. (1983). Factor analysis. Hillsdale, NJ: Lawrence Erlbaum Associates. Kafonek, S., Ettinger, W. H., Roca, R., Kittner, S., Taylor, N., & German, P. S. (1989). Instruments for screening for depression and dementia in a long-term care facility. Journal of the American Geriatric Society, 37,29-34. Koenig, H. G., Meador, K. G., Cohen, H. J., & Blazer, D. G. (1988). Self-rated depression scales and screening for major depression in the older hospitalized patient with medical illness. Journal of the American Geriatric Society, 36,699-706. Magni, G., Schifano, F., & de Leo, D. (1986). Assessment of depression in an elderly medical population. Journal of Aflective Disorders, 1 1 , 121-124. Snowden, J., & Donnelly, N. (1986). A study of depression in nursing homes. Journal of Psychiatric Research, 22,327-333. Vida, S., Gauthier, L., & Gauthier, S . (1989). Canadian collaborative study of tetrahydroaminoacridne ("HA) and lecithin treatment of Alzheimer's disease: Effect on mood. Canadian Journal of Psychiatry, 34, 165-170. Yesavage, J. A., Brink, T. L., Rose, T. L., Lum, O., Huang, V., Adey, M. B., & Leirer, V. 0. (1983) Development and validation of a geriatric depression screening scale: A preliminary report. Journal of Psychiatric Research, 22,37-49. Zarit, S. H. (1 980). Aging and mental disorder. New York: The Free Press. Zemore, R., & Eames, N. (1979). Psychic and somatic symptoms among young adults, institutionalized aged and noninstitutionalized aged. Journal of Gerontology, 34, 716-722.
Note. The GDS has been translated into Chinese, Dutch, French, German, Hebrew, Italian, Japanese, Portuguese, Rumanian, Russian, Spanish, and Yiddish. These translations are available upon request from the authors. Acknowledgment. This research was supported in part by the Medical Research Service of the Veterans Administration and the Clinical Research Center for the Study of Senile Dementias MH-40041. Offprints. Requests for offprints should be addressed to Dr. Yesavage, Professor, Stanford University School ofMedicine, Psychiatry Department, T D l l 4 , Stanford, CA 94305-5490, U.S.A.
