Variables that moderate treatment effects need to be better understood as well (Helgeson, 2005). For example, many individuals diagnosed with cancer report manageable psychological distress that resolves over time without the need for formal services. Other research has found that patients with the highest levels of distress often show the greatest reduction in symptoms when provided psychosocial services (Andrykowski and Manne, 2006; Antoni et al., 2006). Research conducted with individuals with varying availability of social supports has found that the effectiveness of different types of psychosocial services can depend on the nature and extent of those supports (Cohen, 2004). Because of such findings, experts point to the need for a new generation of research on the effectiveness of psychosocial health services (Helgeson, 2005) involving “increasingly careful a priori consideration of the nature of the samples, interventions, and outcomes involved, as well as theory-guided examinations of mechanisms for the obtained effects” (Stanton, 2005:4819). Particular attention should be paid to socially disadvantaged populations, examining the effects of socioeconomic status and race/ethnicity on the risk for psychosocial problems and on the impact of interventions on these problems. Such work should also take into account developmental issues, particularly for children with cancer, and the effectiveness of interventions at different life stages (Zebrack and Zeltzer, 2003).
The strength and generalizability of the evidence generated by research are increased by attention to several research design issues. First, the effectiveness of a service is often measured using dimensions of quality of life. Because measures of quality of life are numerous and variable, what one study finds effective may not be interpreted as such by others. The development of standard outcome measures by which the effectiveness of psychosocial services can be measured would increase the understanding and application of research results.
Research using more rigorous research designs is also needed, including use of longer follow-up periods (Helgeson, 2005). For example, with respect to the effects of psychotropic medications used to treat depression and other mental health conditions of patients with cancer, conclusions about effectiveness are limited (see Chapter 3) because of the few randomized controlled trials that have been done. More such trials are needed, using a larger patient cohort that is studied over a longer period of time to properly assess drug efficacy. These trials will likely require multicenter sites. The trials should be limited to patients with significant levels of depressive or anxious symptoms at baseline (e.g., severe adjustment disorder with depressive or anxious symptoms or anxiety, post-traumatic stress