Evaluation of possible futures.
The second fault concerns the evaluation of future scenarios. Depressed people tend to overestimate, over-weight, and over-attend to risk, and this produces more negative expectations of the future. Depressed people not only judge bad things as highly likely, but also generate more reasons why this would be so (Alloy & Ahrens, 1987; MacLeod, Tata, Kentish, Carroll, & Hunter, 1997). These predictions are overblown (Strunk, Lopez, & DeRubeis, 2006), yet greater depression goes hand in hand with greater certainty about these predictions (Miranda & Mennin, 2007). Depressed people not only expect bad outcomes, but they also expect to have little power to change them, even following experiences of success (Abramson, Garber, Edwards, & Seligman, 1978; Kosnes, Whelan, O'Donovan, & McHugh, 2013; Seligman, 1972).
At the extreme end of pessimism, we find hopelessness and depressive predictive certainty, black-and-white expectations that negative outcomes will occur and positive outcomes will not (Abramson et al., 1989; Andersen, 1990; Beck, Weissman, Lester, & Trexler, 1974; Miranda, Fontes, & Marroquin, 2008). Depressive predictive certainty is toxic: People who are certain that good things will not happen tend to have more suicidal ideation, even after adjusting for depressive symptoms and general hopelessness (Sargalska, Miranda, & Marroquin, 2011). Likewise, hopeless people are at a higher risk of killing themselves (Kovacs & Garrison, 1985), and hopelessness is likely sufficient for causing depression symptoms (Abramson et al., 1989).
These general negative expectations are related to specific simulations of the future: For example, repeatedly simulating emotionally charged scenarios makes them more believable, so repeatedly simulating negative (and not positive) events should produce even more negative expectations (Szpunar & Schacter, 2013). Indeed, the fewer positive events people imagine, the greater their hopelessness (MacLeod et al., 2005).