Jpn J Clin Oncol 2000;30(5)221–224
Suicidal Ideation in Cancer Patients with Major Depression Tatsuo Akechi1,2, Hitoshi Okamura2, Akira Kugaya2,3, Tomohito Nakano2, Tatsuro Nakanishi3,4, Nobuya Akizuki3, Shigeto Yamawaki5 and Yosuke Uchitomi2 1Psychiatry
Division, National Cancer Center Hospital, Tokyo, 2Psycho-Oncology Division, National Cancer Center Research Institute East, Kashiwa, Chiba, 3Psychiatry Division, National Cancer Center Hospital East, Kashiwa, Chiba, 4Department of Psychiatry, Kashiwa Hospital, Jikei Medical University, Kashiwa, Chiba and 5Department of Psychiatry and Neurosciences, Hiroshima University School of Medicine, Hiroshima, Japan
Received January 14, 2000; accepted March 10, 2000
Background: Major depression is a well-documented risk factor for suicide in cancer patients as well as in the general population. However, there are no data explaining why some cancer patients suffering from major depression have suicidal ideation whereas others with the same disorder do not. Methods: We investigated the background differences between cancer patients suffering from major depression with and without suicidal ideation by analyzing consultation data on patients referred to the Psychiatry Division, National Cancer Center Hospital, Japan. Results: Univariate analysis showed that poor performance status, advanced stage and severe depression were the risk factors for suicidal ideation in these depressive cancer patients. Multivariate logistic regression analysis indicated that older age and severe depression are the final significant risk factors. Conclusion: These preliminary findings suggest that severe major depression may be an important indicator of suicidal ideation among cancer patients, that patients’ age should be given greater attention and that closer monitoring and more intensive intervention against major depression may be needed.
Key words: cancer – suicidal ideation – depression
INTRODUCTION
METHODS
Because cancer is a life-threatening illness, its psychological impact on patients has been an important aspect of clinical oncology. It is well known that one of the most common expressions of psychological distress in cancer patients is depressive disorder (1,2). On the other hand, there has been much interest in suicidal ideation in cancer patients since euthanasia and physician-assisted suicide have emerged as important and urgent medical and social issues all over the world (3–6). Several factors, such as uncontrolled pain, advanced illness, loss of control and hopelessness, have been suggested as indicators for vulnerability to suicide in cancer patients (7,8). Also, depressive disorder is a well-documented risk factor for suicide in cancer patients as well as in the general population (9). However, there are no data explaining why some cancer patients suffering from major depression have suicidal ideation whereas others do not. The objective of the present study was to investigate the background differences between cancer patients suffering from major depression with and without suicidal ideation.
All psychiatric consultations referred to the Psychiatry Division, National Cancer Center Hospital East, from July 1996 (when the Psychiatry Division was established) to December 1998 and to the Psychiatry Division, National Cancer Center Hospital, from January 1998 (when the same database system was established) to December 1998 were reviewed by the authors. A computerized database, custom made for the Psychiatry Division, National Cancer Center, was used to identify the risk factors for suicidal ideation in referred cancer patients suffering from major depression. The database included demographic variables such as age, gender, marital status and employment status; medical factors such as cancer site, disease stage, performance status (PS) as defined by Eastern Cooperative Oncology Group (ECOG) criteria, disclosure of cancer diagnosis, brain metastasis, in- or out-patient status and pain; and psychiatric diagnosis evaluated according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) (10). To assess pain, psychiatrists asked patients directly about pain at first interview and pain was evaluated as follows: not at all; a little; tolerable; intolerable. The nine diagnostic criteria for major depression from the DSM-IV are also included in the database. As for the diagnosis of major depression, the diagnostic criteria excluded symptoms due to
For reprints and all correspondence: Yosuke Uchitomi, Psycho-Oncology Division, National Cancer Center Research Institute East, 6–5–1 Kashiwanoha, Kashiwa 277-8577, Japan. E-mail:
[email protected]
© 2000 Foundation for Promotion of Cancer Research
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Suicidal ideation in depressive cancer patients
Table 1. Comparisons of referred depressive cancer patients with and without suicidal ideation Characteristic
Suicidal ideation Presence (N = 61)
Absence (N = 53)
Mean
SD
Mean
SD
t
df
59.6
10.4
55.5
11.9
–1.92
112
Mean
SD
Mean
SD
z
p
Performance status*
1.9
1.4
1.3
1.1
–2.28
0.02
Pain†
1.4
0.9
1.2
0.8
–1.20
0.23
Age (years)
Severity of depression‡
7.0
1.2
6.2
1.0
–3.69
N
%
N
%
χ2
p 0.06
0.0002 df
p
Gender (male)
32
52
25
47
0.32
1
0.57
Marital status (married)
51
84
44
83
0.007
1
0.93
Employment status (full- or part-time)
20
33
25
47
2.46
1
0.12
Advanced stage (recurrent or metastatic)
44
72
28
53
4.54
1
0.03
Brain metastasis (presence)
4
7
1
2
1.48
1
0.37
Psychotic features (presence)
2
4
0
0
1.78
1
0.50
37
61
33
62
0.03
1
0.86
In-patients
*Defined by Eastern Cooperative Oncology Group criteria. †Coded as 1 = not at all; 2 = a little; 3 = tolerable; 4 = intolerable. ‡Severity of depression is defined by the total number of diagnostic criteria present for major depression (excluding suicidal ideation) according to the DSM-IV (10).
the general medical condition (e.g. cancer, anticancer treatment). Because differential diagnosis is often impossible and the etiological diagnostic approach is not considered useful in psycho-oncology practice, we adopted the inclusive approach based on depressive symptomatology regardless of presumed etiology. Only data for cancer patients diagnosed as having major depression (‘depressive cancer patients’) were extracted from the database. These patients were divided into two groups according to the presence or absence of suicidal ideation, which is one of the nine diagnostic criteria for major depression according to the DSM-IV. To investigate the risk factors for suicidal ideation, background data (age, gender, marital status, employment status, disease stage, PS, brain metastasis, in- or out-patient status, pain, severity of depression and psychotic features) were compared between the two groups using univariate analysis. In this study, severity of depression was defined as the number of diagnostic criteria present for major depression, except for suicidal ideation, according to the DSM-IV. Final risk factors were determined by multivariate logistic regression analysis including variables having p < 0.10 in univariate analysis. All data analyses were conducted using SAS statistical software (SAS Institute, 1999).
during the study period. Of that number, 114 (12.9%) were diagnosed as having major depression. Sixty-one (53.5%) of the referred cancer patients with major depression had suicidal ideation, but only two (2.0%) had psychotic features. Thirtyfour (29.8%) patients met all eight diagnostic criteria (excluding suicidal ideation) for major depression according to the DSM-IV. The median number of diagnostic criteria present for major depression (excluding suicidal ideation) was seven. The mean (S.D.) age of these depressive patients was 58 ± 11 years (median, 57 years). Seventy (61.4%) were in-patients. Fifty-seven (50.0%) were female; 42 (36.8%) had full-time work and three (2.6%) had part-time work. Ninety (83.3%) were married (six were single, five were divorced and eight were widowed). The most frequent cancer site was the lung (30.7%), followed by the breast (15.8%) and the head and neck (8.8%). Thirty-seven (32.5%) patients were diagnosed as having metastatic cancer and 35 (30.7%) had recurrence. Five (4.4%) had brain metastasis. Thirteen patients (11.4%) had a PS of 4 and 15 (13.2%) had a PS of 3. Twenty (17.5%) were free from pain, 34 (30.9%) had tolerable pain and 10 (8.8%) had intolerable pain. All patients were informed of the cancer diagnosis.
RESULTS
Comparisons of referred depressive cancer patients with and without suicidal ideation are shown in Table 1. Univariate analysis showed that three characteristics, namely poor performance status, advanced stage and severe depression, were significant risk factors and older age was a statistically borderline risk factor for suicidal ideation in the subjects.
PATIENT DEMOGRAPHIC AND MEDICAL CHARACTERISTICS A total of 885 cancer patients were referred to the Psychiatry Division, National Cancer Center Hospital and Hospital East
RISK FACTORS FOR SUICIDAL IDEATION
Jpn J Clin Oncol 2000;30(5)
Table 2. Logistic regression analysis of risk factors for suicidal ideation in referred cancer patients with major depression Variable
β
SE
Odds ratio
95% CI*
p
Age (years)
0.04
0.02
1.04
1.00–1.09
0.04
Performance status†
0.23
0.18
1.26
0.89–1.82
0.20
Advanced stage 0.81 (recurrent or metastatic)
0.49
2.29
0.87–5.97
0.10
Severity of depression‡ 0.63
0.19
1.88
1.31–2.81
0.001
*Confidence interval. †Defined by Eastern Cooperative Oncology Group criteria. ‡Severity of depression is defined by the total number of diagnostic criteria present for major depression (excluding suicidal ideation) according to the DSM-IV (10).
Logistic regression analysis including these four factors as the independent variables revealed that older age and severe depression were significant risk factors (Table 2).
DISCUSSION This is the first preliminary study that provides information about risk factors for suicidal ideation in depressive cancer patients based on clinical experience. Prior studies showed that depressive disorder is one of the most common psychiatric problems in cancer patients and that approximately 20% of all cancer patients suffer from major depression (1). This study showed that more than half (53.5%) of the referred depressive cancer patients had suicidal ideation. Since the subjects of our study were the patients referred to the Psychiatry Division, the sampling bias may be problematic. However, the prevalence rate of suicidal ideation may not be low and the rate we identified is similar to that indicated in previous studies investigating the prevalence of suicidal ideation among depressive patients in a psychiatric setting (11). The result of a high prevalence of suicidal ideation in depressive cancer patients may indicate that major depression should not be underestimated and that suicidal ideation should always be taken into consideration when assessing depressive cancer patients. This result suggests that oncology staff members need to treat cancer patients suffering from major depression carefully to prevent suicide. The present study provides a clue to understanding why some cancer patients with major depression have suicidal ideation whereas others do not. Several risk factors for suicidal ideation in depressive cancer patients were identified. Univariate analysis indicated that older age, poor performance status, advanced disease stage and severe depression were the possible risk factors, despite the lack of a significant association between suicidal ideation and important demographic factors such as marital status and deleterious physical distress such as pain (7–9). A previous study investigating risk factors for suicide in depressed patients in a psychiatric setting indicated that significant suicide-related factors were previous suicide attempt, being unmarried and living alone (12). That study suggested that social isolation enhanced suicidal tendencies among depressed patients. Our results may not be
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consistent with this result; however, this is not surprising because of the difference in subjects. On the other hand, a lack of significant association between pain and suicidal ideation in the present study may be interesting since pain is considered to be one of the major risk factors for suicide in cancer patients. The present study may suggest that pain is a major risk factor for major depression, but not for suicidal ideation and that pain has an influence on suicidal ideation through depression. Our findings showed that depressive cancer patients who are older with a poor performance status, advanced disease and more severe depression should be carefully and intensively monitored to prevent suicide. Multivariate analysis showed that only older age and severity of depression were significant risk factors. In the general population, age (60 years or older) is shown to be an indicator for vulnerability to suicide (9) and our result may be consistent with this, despite the difference in subjects. Our previous study investigating predictive factors of patients’ mental adjustment to cancer indicated that older age is a significant factor predicting a deleterious mental adjustment to cancer (helplessness/hopelessness) (13). Hence one of the age-related factors may be mental adjustment to cancer, but further study is needed to clarify this association. The significant association between suicidal ideation and severity of depression seems reasonable and severe major depression may be an important clinical indicator of the presence of suicidal ideation in cancer patients. In the present study, however, the definition of severity of major depression may be somewhat problematic since our diagnostic approach in clinical practice (inclusive approach) includes physical symptoms which may be produced in cancer and anticancer treatment themselves. To clarify the association, stricter diagnostic criteria are needed. This preliminary retrospective study has several limitations. Some important information, such as physical distress other than pain, past history of suicide ideation, past history of major depression, anxiety, feelings of loss of control, social support, patient–doctor relationship, economic status, individual coping style and others, are not included. Also, the referred patient sample may have been influenced by physician bias. Further well designed studies are needed to investigate why some depressive cancer patients have suicidal ideation and others do not.
Acknowledgments We thank Ms Yuko Kojima, Ms Ryoko Katayama, Ms Yurie Sugihara and Ms Naomi Suimon of the Psycho-Oncology Division, National Cancer Research Institute East, for their research assistance. This study was supported in part by a Grant-in-Aid for Cancer Research (11-31) from the Japanese Ministry of Health and Welfare.
References 1. McDaniel JS, Musselman DL, Porter MR, Reed DA, Nemeroff CB. Depression in patients with cancer. Diagnosis, biology and treatment. Arch Gen Psychiatry 1995;52:89–99. 2. Spiegel D. Cancer and depression. Br J Psychiatry 1996;168:109–16.
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3. Quill TE, Lo B, Brock DW. Palliative options of last resort. A comparison of voluntarily stopping eating and drinking, terminal sedation, physicianassisted suicide and voluntary active euthanasia. J Am Med Assoc 1997;278:2099–104. 4. Kissane DW, Street A, Nitschke P. Seven deaths in Darwin: case studies under the Rights of the Terminally Ill Act, Northern Territory, Australia. Lancet 1998;352:1097–102. 5. Akechi T, Kugaya A, Okamura H, Nakano T, Okuyama T, Mikimi I, et al. Suicidal thoughts in cancer patients: clinical experience in psycho-oncology. Psychiat Clin Neurosci 1999;53:569–73. 6. Chin AE, Hedberg K, Higginson GK, Fliming DW. Physician-assisted suicide in Oregon – the first year’s experience. N Engl J Med 1999;340:577–83. 7. Massie MJ, Gagnon P, Holland JC. Depression and suicide in patients with cancer. J Pain Symptom Manage 1994;9:325–40.
8. Breitbart W, Passik SD. Psychiatric aspects of palliative care. In: Doyle D, Hanks GWC, Macdonald N, editors. Oxford Textbook of Palliative Medicine. Oxford: Oxford University Press 1995;609–26. 9. Hirschfeld RMA, Russell JM. Assessment and treatment of suicidal patients. N Engl J Med 1997;337:910–5. 10. Diagnostic and Statistical Manual of Mental Disorders, 4th ed. Washington, DC: American Psychiatric Association 1995. 11. Wada K, Murao J, Hikasa K, Ota J, Kinoshita S, Yoshinari H, et al. A clinical analysis of the suicidal ideation of outpatients with major depression. Sheishin Igaku 1998;39:1077–82 (in Japanese). 12. Roy A. Suicides in depressives. Comp Psychiatry 1983;24:487–91. 13. Akechi T, Okamura H, Yamawaki S, Uchitomi Y. Predictors of patients’ mental adjustment to cancer: patient characteristics and social support. Br J Cancer 1998;77:2381–5.
