Perceived threat and depression among patients with cancer: the moderating role of health locus of control

Abstract

Illness perception was found to be a better predictor of psychological outcome among cancer patients than the objective characteristics of illness. The current study explored the association between the perceived threat of illness (a major aspect of illness perception) and depression among cancer patients. We examined the hypothesis that this association will be higher for persons with low External (others) or internal (self) Health Locus of Control (HLC) than for those with high HLC. The study took an exploratory approach regarding the role that different sources of control (external and internal) may assume. Fifty-seven cancer patients completed self-report measures of Perceived Life Threat (PLT), HLC and Depression. The possible moderating role of HLC on the relationship between PLT and Depression was examined. A significant relationship between perceived threat and depression was found only among participants reporting low levels of internal locus of control. The results support the hypothesis that perception of cancer as life threatening is important factor in determining the level of depression among cancer patients. The results also support the differentiation between internal and external HLC and suggest that internal HLC may be more relevant than external HLC in managing perceived threat. Internal locus of control can be interpreted as having a sense of agency and mastery which is important in managing the cognitive perception of the threat of illness. Further research is needed in order to determine the role of external HLC in managing perceived or actual threats.

Keywords: Cancer; Perceived threat; depression; health locus of control; oncology.