Practical Geriatrics: Immune Function, Mood, and Perceived Burden Among Caregivers Participating in a Psychoeducational Intervention

Table 1 shows study participants' mean scores on measures of immune function, depression, anxiety, and perceived burden. The participants showed a significant deterioration in T cell proliferation to PHA from baseline to the completion of the eight-week psychoeducational intervention, indicating a decline in immune status; the control group showed no fluctuation in immune function. Comparison of baseline and end-of-intervention measures also showed trends for increases in perceived burden as measured by the Zarit Burden Scale and depressed mood as measured by the GDS.

T cell proliferation to PHA at one-month follow-up revealed a trend for improvement from the end of the intervention. The mean GDS score was lower at follow-up than at baseline and showed a trend for improvement from the end of the intervention. Mean scores on the Zarit Burden Scale and the Beck Anxiety Scale improved from the end of the intervention to the one-month follow-up, but the changes were not significant. Mean scores on the BDI showed a trend for improvement from baseline to follow-up one month after completion of the intervention.

All 11 caregivers rated the group as "highly beneficial," a score of 5 on a 5-point Likert-type scale. Caregivers' scores on the MMSE were in the normal range (mean=28.6). Conversely, the mean MMSE score of the husbands declined significantly from baseline to follow-up (mean±SD= 13.27, compared with 9.22 at follow-up; t=2.85, df=7, p=.02).

Psychoeducational groups are frequently recommended for caregivers of patients with dementia. In the study reported here, it is noteworthy that the spouse caregivers had a significant deterioration in their immune function from baseline to completion of the psychoeducational intervention. The decline in immune status was associated with increases in perceived burden and depressed mood. However, all caregivers rated the treatment intervention as highly beneficial. The positive perception may reflect caregivers' relief at having time away from the burden of caring for their spouse with dementia.

Previous studies have established that caregivers of patients with dementia manifest increased levels of depression and perceived burden, along with reduced immune function (1,2,3). Thus they are a group in need of treatment services to improve their emotional and physical health. However, the results of outcome studies of psychoeducational interventions for this group are mixed; some studies have shown a reduction in depression, anxiety, and perceived burden, and others have shown no effect (3).

Several factors may have contributed to our study results. First, the psychoeducational process may be inherently stressful to spouse caregivers, because it increases awareness of the severity of their situation, and it may thereby initially worsen immune and psychological symptoms. Second, the caregivers' experience of the decline in function of their husband's mental state may have outweighed any beneficial effects of the program. Finally, the caregivers' anticipation of the loss of the weekly supportive group sessions might have contributed to the decline in immune and psychological function after the psychoeducational intervention was over.

Psychoeducational treatment for spouse caregivers that is not time limited, such as the ongoing support groups provided by the Alzheimer's Association, may help prevent the declines in physiological and psychological function noted in this study. Groups that are not time limited offer more opportunity to process information and feelings and may prove less acutely stressful for caregivers. The interaction of time in treatment with study outcome may help to explain why the study participants showed a trend for improved psychological and immune function at the one-month follow-up. In addition, individual psychotherapy has been reported to help some spouse caregivers of demented patients (12).

The findings of this study, along with those reported in the literature, suggest that future research will benefit from random assignment of caregivers to specific psychoeducational or other treatment interventions and use of a control group for monitoring immune and psychological parameters. Future research will also have to address the extensive variation that currently exists in group treatments for caregivers, including variation in the duration of the interventions; the type and structure of group formats, such as psychoeducational versus supportive; and whether respite care is provided for the demented patient. Further research will help determine whether time-limited and focused psychoeducation for spouse caregivers may be inherently stressful, especially as the treatment process increases caregivers' awareness of their predicament.

In summary, the potential for psychoeducational groups to diminish caregivers' immune and psychological function, at least during early phases of treatment, is an area that requires critical examination in caregiving populations.

This study was supported by Geriatric Academic Program Award AG-00489-01 from the National Institute on Aging, the Department of Veterans Affairs Geriatric Research Education and Clinical Center Service, and the UCLA Center for Interdisciplinary Research in Immunology and Disease.

Dr. Wilkins is chief psychologist and Dr. Castle is clinical director at the Department of Veterans Affairs Geriatric Research Education and Clinical Center (11G) at the West Los Angeles Veterans Affairs Medical Center, 11301 Wilshire Boulevard, Los Angeles, California 90073 (e-mail, [email protected]). Dr. Wilkins is also assistant professor and Dr. Castle is associate professor in the department of medicine at the University of California, Los Angeles, School of Medicine. Ms. Heck is a social worker with the Los Angeles Alzheimer's Association. Dr. Tanzy is a psychologist in private practice in Seattle. Dr. Fahey is director of the Center for Interdisciplinary Research in Immunology and Disease at UCLA. The editor of this column is Marion Z. Goldstein, M.D.