Psychological Reporb, 1992, 7 1, 208-210. @ Psychological Reports 1992
PREVALENCE O F VARIOUS DEPRESSIVE SYMPTOMS IN A SAMPLE O F THE GENERAL POPULATION ' J. GIBSON HENDERSON, JR. AND C. ALEC POLLARD Saint Louis University School of Medicine Summary.-Data on prevalence of and demographics associated with various symptoms of depression are reported for a sample of the general population. Of the nine symptoms assessed, the most frequently occurring were dysphoric mood (17.8%), increased sleep (15%), and loss of interest in other people or activities previously enjoyed (11 8%) 39% of subjects reported one or more symptoms of depression. 8% of subjects reported wondering if life is worth living, a symptom that in and of itself is suggestive of dinically significant depression. The number of depressive symptoms reported was related to income, education, age, and residence (city veaus county), but not to sex. The findings provide evidence that various symptoms of depression may be more common in the general population than previously suspected.
Recent NIMH-sponsored epidemiologic studies (3), the Epidemiologic Catchment Area (ECA) project, have reported 6-month prevalence rates at New Haven, Baltimore, and St. Louis research sites, respectively, of 3.5%, 2.2%, and 3.2% for major depressive episode without bereavement; of 0.3%, 0.2%, and 0.1% for bereavement; and 3.2%, 2.1%, and 3.8% for dysthy rnia. Over-all rates for any affective disorder were 6.5%, 4.6%, and 6 2% The ECA study provided important data regarding the prevalence of hagnoses related to depression but did not include information about the prevalence of various symptoms of depression in the general population. In the present paper data concern prevalence of and demographics associated with various symptoms of depression in a sample examined as part of a larger epidemiologic study (5) of several psychiatric disorders. Method.-The study included 250 male and 250 female adult residents randomly selected from the greater St. Louis area. Telephone numbers were generated randomly by computer to include the 20% of all households with unlisted numbers. Approximately 90% of the subjects selected were eventually contacted and agreed to participate. Distributions across age, income, education, and residential location were generally representative of the population of greater St. Louis, although the phone methodology precluded homeless individuals and others without telephones. All subjects participated in a structured telephone interview designed to assess the symptoms of major affective disorder and dysthymia described in DSM-I11 (I), with modifications to accommodate the telephone methodology. Questions on the inter'Addtess re uests for r y + t s to J. G . Hendcrqn. Jr.. F p a r t m e n t of Psychiatry and Human Behavior, ~ i o o of l Me lcme, St LOUISUmverslty Mehcal Center, 1221 S. Grand Blvd., St. Louis, MO 63104.
207
PREVALENCE: DEPRESSIVE SYMPTOMS
view assessed major symptoms of depression, but because of the need for brevity in assessing multiple disorders by telephone, did not include d possible symptoms. Differentiations among subtypes of affective disorders and exclusion of other disorders that might have an affective component were not made. Results.-The frequency of occurrence for each symptom was as follows: Symptom
n
%
Feeling unusually sad or down in the dumps Sleeping a lot more than usual Lost interest in other people or activities once enjoyed More trouble falling asleep Harder to think or make decisions Waking up too early without being able to fall back asleep Wondering more if life is worth living Unintentional loss of weight or appetite in the past two months Sex drive or interest has decreased
One hundred and ninety-five subjects (39%) had one or more symptoms of depression. (Sleep difficulty was counted as one symptom only, regardless of whether one, two, or all three of the sleep questions elicited a positive response.) Two or more symptoms were reported by 101 subjects (20.2%), 57 subjects (11.4%) had three or more symptoms, 33 subjects (6.6%) had four or more symptoms, 13 subjects (2.6%) had five or more symptoms, and 7 subjects (1.4%) had six or more symptoms. Two subjects (0.4T0'0)acknowledged a l l seven of the symptoms assessed. Analysis of variance comparing the numbers of depressive symptoms present in various demographic groups showed that the number of symptoms present was related to income level, education, age, and residence (city versus county). The mean number of symptoms for women was higher than for men, but the difference was not statistically significant ( p = .l3). Individuals with income under $10,000 had more symptoms than individuals with income from $26,000-40,000 or from $41,000-60,000 (but not significantly more than those with income of $10,000-25,000 or over $60,000). Individuals with income from $10,000-25,000 had more symptoms than those with income from $26,000-40,000, $41,000-60,000, and over $60,000. People with a high school education had more symptoms of depression than people with a college education or postgraduate education. Individuals under 25 years of age had more symptoms of depression than any of the other age groups surveyed (25-35, 36-45, 46-54, 55-65, over 65 yr.). City residents had more symptoms of depression than county residents. Discussion.-These findings suggest a much higher portion (37%) of the population experiences some aspects of depression than that which meets full
210
J. G. HENDERSON, JR. & C. A. POLLARD
criteria for a depression-related diagnosis. The clinical significance, however, of any single depressive symptom is uncertain. Diagnosis of major affective disorder requires the presence of at least five such symptoms, while diagnosis of dysthymic disorder requires the presence of depressed mood and at least two other symptoms. Nonetheless, it is worth noting that 8% of subjects wondered if life was worth living, a response that seems more likely in and of itself to be indicative of clinical depression. Furthermore, 2.6% of the sample endorsed five or more items. Demographic findings of increased symptomatology in individuals who were younger, who had less education, who had lower income, and who resided in urban rather than rural or suburban areas are consistent with prior research on depression (2, 3, 4). However, the failure to find more symptoms in women than men was not. Given the trend toward more symptoms for women, the discrepancy might be attributable to moderate sample size. Results must be interpreted in light of limitations associated with a structured interview, moderate sample size, and the potential for subjects' response bias. In addition, due to the use of a telephone interview format, these findings may not generalize to homeless individuals or other individuals without a telephone. Nonetheless, present findings provide evidence that various symptoms of depression may be more common in the general population than previously suspected, with dysphoria being the most common depressive symptom. The clinical significance of each of these symptoms and of different symptom combinations should be evaluated by further research. REFERENCES 1. AMEMCANPSYCHIATRIC ASSOCIATION. (1980) Diagnostic and staristical manual of mental disorders. (3rd ed.) Washington, DC: Author. P. M., HOBERMAN, H. M., & ROSENBAUM, M. (1988) A prospective study of 2. LEWINSOHN, risk factors for unipolar depression. ]ournu1 of Abnormal Psychology, 97, 251-264. 3. MYERS,J. K., WEISSMAN,M. M., TISCHLER,G. L., HOLZER,C. F., LEAF, P J., ORVASCHEL, R. (1984) H., ANTHONY,. C., BOYD,J. H., BURKE,J . D., KRAMER,M., & STOLTZMAN, 6-month prev ence of psychiatric disorders in three communities. Archives of General Psychiatry, 41, 959-967. 4. NOLL, G. A., & DUBINSKY, M. (1985) Prevalence and predictors of depression in a suburban county. Journal of Community Psychology, 13, 13-19. C. A,, & HENDERSON, J. G., JR. (1986) Prevalence of anxiety disorders in a major 5. POLLARD, metropolitan community. Paper presented at the meeting of the American Psychological Association, Washington, DC.
d
Accepted June 22, 1992
PREVALENCE O F VARIOUS DEPRESSIVE SYMPTOMS IN A SAMPLE O F THE GENERAL POPULATION ' J. GIBSON HENDERSON, JR. AND C. ALEC POLLARD Saint Louis University School of Medicine Summary.-Data on prevalence of and demographics associated with various symptoms of depression are reported for a sample of the general population. Of the nine symptoms assessed, the most frequently occurring were dysphoric mood (17.8%), increased sleep (15%), and loss of interest in other people or activities previously enjoyed (11 8%) 39% of subjects reported one or more symptoms of depression. 8% of subjects reported wondering if life is worth living, a symptom that in and of itself is suggestive of dinically significant depression. The number of depressive symptoms reported was related to income, education, age, and residence (city veaus county), but not to sex. The findings provide evidence that various symptoms of depression may be more common in the general population than previously suspected.
Recent NIMH-sponsored epidemiologic studies (3), the Epidemiologic Catchment Area (ECA) project, have reported 6-month prevalence rates at New Haven, Baltimore, and St. Louis research sites, respectively, of 3.5%, 2.2%, and 3.2% for major depressive episode without bereavement; of 0.3%, 0.2%, and 0.1% for bereavement; and 3.2%, 2.1%, and 3.8% for dysthy rnia. Over-all rates for any affective disorder were 6.5%, 4.6%, and 6 2% The ECA study provided important data regarding the prevalence of hagnoses related to depression but did not include information about the prevalence of various symptoms of depression in the general population. In the present paper data concern prevalence of and demographics associated with various symptoms of depression in a sample examined as part of a larger epidemiologic study (5) of several psychiatric disorders. Method.-The study included 250 male and 250 female adult residents randomly selected from the greater St. Louis area. Telephone numbers were generated randomly by computer to include the 20% of all households with unlisted numbers. Approximately 90% of the subjects selected were eventually contacted and agreed to participate. Distributions across age, income, education, and residential location were generally representative of the population of greater St. Louis, although the phone methodology precluded homeless individuals and others without telephones. All subjects participated in a structured telephone interview designed to assess the symptoms of major affective disorder and dysthymia described in DSM-I11 (I), with modifications to accommodate the telephone methodology. Questions on the inter'Addtess re uests for r y + t s to J. G . Hendcrqn. Jr.. F p a r t m e n t of Psychiatry and Human Behavior, ~ i o o of l Me lcme, St LOUISUmverslty Mehcal Center, 1221 S. Grand Blvd., St. Louis, MO 63104.
207
PREVALENCE: DEPRESSIVE SYMPTOMS
view assessed major symptoms of depression, but because of the need for brevity in assessing multiple disorders by telephone, did not include d possible symptoms. Differentiations among subtypes of affective disorders and exclusion of other disorders that might have an affective component were not made. Results.-The frequency of occurrence for each symptom was as follows: Symptom
n
%
Feeling unusually sad or down in the dumps Sleeping a lot more than usual Lost interest in other people or activities once enjoyed More trouble falling asleep Harder to think or make decisions Waking up too early without being able to fall back asleep Wondering more if life is worth living Unintentional loss of weight or appetite in the past two months Sex drive or interest has decreased
One hundred and ninety-five subjects (39%) had one or more symptoms of depression. (Sleep difficulty was counted as one symptom only, regardless of whether one, two, or all three of the sleep questions elicited a positive response.) Two or more symptoms were reported by 101 subjects (20.2%), 57 subjects (11.4%) had three or more symptoms, 33 subjects (6.6%) had four or more symptoms, 13 subjects (2.6%) had five or more symptoms, and 7 subjects (1.4%) had six or more symptoms. Two subjects (0.4T0'0)acknowledged a l l seven of the symptoms assessed. Analysis of variance comparing the numbers of depressive symptoms present in various demographic groups showed that the number of symptoms present was related to income level, education, age, and residence (city versus county). The mean number of symptoms for women was higher than for men, but the difference was not statistically significant ( p = .l3). Individuals with income under $10,000 had more symptoms than individuals with income from $26,000-40,000 or from $41,000-60,000 (but not significantly more than those with income of $10,000-25,000 or over $60,000). Individuals with income from $10,000-25,000 had more symptoms than those with income from $26,000-40,000, $41,000-60,000, and over $60,000. People with a high school education had more symptoms of depression than people with a college education or postgraduate education. Individuals under 25 years of age had more symptoms of depression than any of the other age groups surveyed (25-35, 36-45, 46-54, 55-65, over 65 yr.). City residents had more symptoms of depression than county residents. Discussion.-These findings suggest a much higher portion (37%) of the population experiences some aspects of depression than that which meets full
210
J. G. HENDERSON, JR. & C. A. POLLARD
criteria for a depression-related diagnosis. The clinical significance, however, of any single depressive symptom is uncertain. Diagnosis of major affective disorder requires the presence of at least five such symptoms, while diagnosis of dysthymic disorder requires the presence of depressed mood and at least two other symptoms. Nonetheless, it is worth noting that 8% of subjects wondered if life was worth living, a response that seems more likely in and of itself to be indicative of clinical depression. Furthermore, 2.6% of the sample endorsed five or more items. Demographic findings of increased symptomatology in individuals who were younger, who had less education, who had lower income, and who resided in urban rather than rural or suburban areas are consistent with prior research on depression (2, 3, 4). However, the failure to find more symptoms in women than men was not. Given the trend toward more symptoms for women, the discrepancy might be attributable to moderate sample size. Results must be interpreted in light of limitations associated with a structured interview, moderate sample size, and the potential for subjects' response bias. In addition, due to the use of a telephone interview format, these findings may not generalize to homeless individuals or other individuals without a telephone. Nonetheless, present findings provide evidence that various symptoms of depression may be more common in the general population than previously suspected, with dysphoria being the most common depressive symptom. The clinical significance of each of these symptoms and of different symptom combinations should be evaluated by further research. REFERENCES 1. AMEMCANPSYCHIATRIC ASSOCIATION. (1980) Diagnostic and staristical manual of mental disorders. (3rd ed.) Washington, DC: Author. P. M., HOBERMAN, H. M., & ROSENBAUM, M. (1988) A prospective study of 2. LEWINSOHN, risk factors for unipolar depression. ]ournu1 of Abnormal Psychology, 97, 251-264. 3. MYERS,J. K., WEISSMAN,M. M., TISCHLER,G. L., HOLZER,C. F., LEAF, P J., ORVASCHEL, R. (1984) H., ANTHONY,. C., BOYD,J. H., BURKE,J . D., KRAMER,M., & STOLTZMAN, 6-month prev ence of psychiatric disorders in three communities. Archives of General Psychiatry, 41, 959-967. 4. NOLL, G. A., & DUBINSKY, M. (1985) Prevalence and predictors of depression in a suburban county. Journal of Community Psychology, 13, 13-19. C. A,, & HENDERSON, J. G., JR. (1986) Prevalence of anxiety disorders in a major 5. POLLARD, metropolitan community. Paper presented at the meeting of the American Psychological Association, Washington, DC.
d
Accepted June 22, 1992
