Table 2 Stress proposition—inference to best explanation

Hill’s aspects of association

Strength

Expectation and lack of support both have strong associations with depression

Consistency

The role of stress as a cause of depression has been found in different situations. The role of expectations and lack of support has also been found

Specificity

No specificity identified

Temporality

No temporality demonstrated in this study

Biological gradient

Higher the causes of stress the higher the observed depression

Plausibility

The association between stress and depression is biologically plausible

Coherence

The association is coherent with what is know

Experimental evidence

Interventions that provide support have been demonstrated to reduce depression

Analogy

There is an analogy between the effect of loss of expectation and loss of support. Both result in a similar effect.

Thagard’s Principles

Symmetry

There is symmetry between stress causing depression and support preventing depression

Explanation

The stress proposition a) coheres with evidence on depression, b) evidence on role of support, isolation, loss of control, and c) is single proposition.

Analogy

Stress causing depression is coherent with stress causing anxiety and physiological changes to H-P axis

Data priority

Proposition describes observation re isolation, expectations, support.

Contradiction

There are no contradictory proposals

Competition

No competitive explanation identified where p and q were not explanatorily connected

Acceptance

The stress proposition is coherent with the overall system of propositions

Thagard’s Criteria

Consilience

The central role of stress as an explanation for depression explains the largest range of facts

Simplicity

Stress as a necessary cause of depression is a simple explanation

Analogy