Psychosocial intervention research: Challenges, strategies and measurement issues

Impediments to demonstrating evidence of effectiveness of psychosocial interventions include a dearth of studies that optimize the likelihood of empirical proof of efficacy for interventions clinicians believe are beneficial and a lack of consensus about outcome measures. Two articles on psychosocial interventions in this issue pose provocative questions and challenges for future research. Investigators have been conducting studies of psychosocial interventions to improve the well-being of people with dementia and their caregivers for more than two decades. Nevertheless, many interventions that seemed to hold great promise and appeared to clinicians to be effective in individual cases have not been rigorously tested to provide an evidence base for implementation in best practice care. Those that have been tested often had disappointing findings, as Zarit and Femia point out in their article in this issue, perhaps because they are based on false premises, such as assuming caregiving is a disorder like (or always causing) depression. One solution they recommend is to only enroll caregivers who have a problem the intervention is designed to address. They also suggest hypothesizing different outcomes based on initial scores. Given the difficulty and expense of recruiting study participants, the latter is a more practical suggestion, as more applicants would be eligible. Moreover, the intervention may prevent disorders, rather than cure them, as was evident in the New York University (NYU) Caregiver Intervention (NYUCI). While in some cases the intervention reduced the number of symptoms of depression in caregivers, in many others it appeared to prevent increasing numbers of symptoms, in comparison to a usual care control group (Mittelman et al., 1995; Mittelman, Roth, Coon, & Haley, 2004a). Thus, the appropriate target group for this intervention would not necessarily be caregivers who had high depression scores, even if the outcome were to have a significant effect on depression. In the NYU study, which followed a large number of caregivers for many years with repeated followups, we were able to categorize hypothesized outcomes into more proximal and more distal effects according to a theoretical model. For example, the stress process model (Pearlin, Mullin, Semple, & Skaff, 1990) would suggest that social support and caregiver appraisal are mediators of such outcomes as caregiver depression and nursing home placement of the person with dementia. The NYUCI had an effect on caregiver support that was observable at the first follow-up after enrollment, which in turn had an effect on caregiver depression at a later observation point (Mittelman et al. 2004a; Roth, Mittelman, Clay, Madan, & Haley, 2005) Depending on the focus of the intervention, immediate outcomes that might be affected could include greater knowledge of illness, acceptance and adjustment to illness, improved caregiving skills (bathing, feeding, etc.), improved coping strategies, more satisfactory support from family members or even just better sleep. These outcomes could result in less depression or anxiety at some later point in time, especially if ongoing support is included as part of the intervention. An additional issue is the sustainability of improved outcomes, which is especially important when the caregiver is the target of the intervention, as dementia generally lasts for many years. When the person with dementia is the target, perhaps changes cannot be sustained as the dementia becomes more severe. The intervention might still be deemed worthwhile if it improves the person’s quality of life, even temporarily. When staff members of facilities serving people with dementia are the targets, it is important to assess whether the gains achieved by the intervention can be maintained after the interventionist leaves. An intervention that improves job satisfaction may reduce job turnover, which would result in less need for repeated training of new staff.