1 Psychology & Health, 2010 (Article in press). RESEARCH ARTICLE Predictors of distress in cancer patients and their partners - The role of optimism in the sense of coherence construct M. Gustavsson-Lilius* 1 , J. Julkunen 1,2 , P. Keskivaara 1 , J. Lipsanen 1 and P. Hietanen 3 1 Department of Psychology, University of Helsinki, Finland 2 Rehabilitation Foundation, Helsinki, Finland 3 Finnish Medical Journal, Helsinki, Finland Abstract PURPOSE: The aim of this study was to clarify the associations between sense of coherence (SOC), dispositional optimism, and distress (i.e. anxiety and depression) in cancer patients and their partners. METHODS: The associations between SOC, dispositional optimism (LOT-R), depression (BDI-14) and anxiety (EMAS-State) were studied in 147 cancer couples. The data were collected with self-report questionnaires at the time of diagnosis (2 months) and six months later. Path analysis was used to analyse the predictors of follow-up distress and crossover effects in the longitudinal data. RESULTS: Optimistic patients and patients with strong SOC as well as their partners reported fewer symptoms of depression and anxiety than less optimistic subjects and subjects with weaker SOC. Optimism explained partially the effect of SOC on distress and SOC seemed to be an independent factor in predicting distress. Patient and partner distress at baseline and at 8-month follow-up correlated positively. In addition, high partner optimism at baseline seemed to predict low patient anxiety at follow-up. CONCLUSIONS: The beneficial effects of SOC seem to include also other elements beyond optimism. In clinical practice, enhancing optimistic expectations of the future and promoting SOC could be expected to reduce distress in cancer patients and their partners. KEYWORDS: Optimism, SOC, distress, cancer, oncology, couples *Correspondence: Mila Gustavsson-Lilius, M.A., Institute of Behavioural Sciences, P.O. Box 9, 00014 University of Helsinki, Finland. Email: mila.gustavsson@helsinki.fi. Introduction Receiving a cancer diagnosis is for most people extremely frightening and often leads to elevated levels of psychological distress, increased anxiety and depression being the most common symptoms (Hagedoorn, Sanderman, Bolks, Tuinstra & Coyne, 2008; Miovic & Block, 2007). In addition to the individual, cancer affects the whole family. Cancer patients’ family members, especially female caregivers, often suffer from elevated levels of emotional distress (Hagedoorn, Buunk, Kuijer, Wobbes, & Sanderman, 2000; Pitceathly & Maguire, 2003), although the mean scores seem to be below clinical cutpoints (Hagedoorn et al., 2008). Family members, especially partners, are usually the main source of support for cancer patients. In addition to within-person effects, there seems to be great interdependence in the impact of the cancer disease on patients’ and their partners’ emotional and everyday life (Giese-Davis, Hermanson, Koopman, Weibel & Spiegel, 2000; Hagedoorn et al., 2008). Partners’ influence on each other and adjustment to cancer Growing literature has provided a general consensus that patients and partners are involved in each other’s support processes by influencing the experience of one another. This so-called crossover or transitive effect has been studied earlier in non-clinical samples (Westman, Vinokur, Hamilton, & Roziner, 2004), and recently in clinical samples as well (Hagedoorn et al., 2008; Ruiz, Matthews, Scheier & Schultz, 2006). Previous literature on personality resources in stressful life events provide evidence that patient-perceived partner support and partner’s positive general expectancies enhance patient’s adjustment (Baider, Cooper, & Kaplan De-Nour, 2000; Ben-Zur, Gilbar & Lev, 2001), coping, and quality of life (Gustavsson-Lilius, Julkunen, & Hietanen, 2007a; Northouse et al., 2002; Schröder & Schwartzer, 2001), and predict lower levels of depression (Knoll, Schwartzer, Pfüller & Kniele, 2009). Recently, researchers have demonstrated significant correlations in emotional distress and similar trajectories in distress (Segrin et al., 2005), as well as in levels of adjustment within cancer dyads, irrespective of cancer type or illness stage (Hagedoorn et al., 2008; Pitceathly & Maguire, 2003). It seems that alleviating cancer patient’s and partner’s distress is better achieved by focusing on both patient and partner characteristics than on individual factors. Consequently, a more detailed investigation of this issue is needed.