Cognitive and metacognitive factors in reduced worry

In the intriguing paper " Do Metacognitions and Intolerance of Uncertainty Predict Worry in Everyday Life? An Ecological Momentary Assessment Study" by Carolin Thielsch, Tanja Andor and Thomas Ehring (just published in Behavior Therapy (2015), http://dx.doi.org/10.1016/j.beth.2015.05.001)

it is suggested that "...Although negative metacognitions thus appear to show a closer association with worry than the core component of the IoU model, there is some evidence that the combination of both cognitive variables may be related to increased explanatory power showing either additive effects (e.g., Thielsch et al., 2015) or even interactive effects (e.g.; Ruggiero et al., 2012)..."

Therefore "...A combined perspective may therefore be valuable, whereby intolerance of uncertainty is suggested as a vulnerability factor and negative metacognitive beliefs as a crucial variable involved in the maintenance of worry by leading to vain attempts of thought control. ..."

Repetitive negative thinking (RNT) may depend on either (or both) metacognitive appraisals regarding the nature of the thinking or on cognitive beliefes focused on the world, the self or other people.
In the case of generalized anxiety disorder (GAD) worry may be increased by either (Thielsch, Andor e Ehring, 2015) metacognitions about worry itself and/or a cognitive belief: Intolerance of Uncertainty (IoU).
Negative metacognitions appear to show a closer association with worry than the core component of the IoU model
On the other hand, there is some evidence that the combination of both cognitive variables may be related to increased explanatory power showing either additive effects (e.g., Thielsch et al., 2015) or even interactive effects (e.g.; Ruggiero et al., 2012).
A combined perspective whereby intolerance of uncertainty is a vulnerability factor and negative metacognitive beliefs as a maintenance factor for worry by leading to vain attempts of thought control.