Article "No differences in visual theory of mind abilities between euthymic bipolar patients and healthy controls" (22nd)

Clarisa Livia
16611022


A recent meta-analyses indicates the occurrence of a ToM deficit in bipolar patients across all mood states, with remitted or subsyndromal patients showing stable modest deficits, albeit less severe than during acute episodes (Bora et al. 2016). Nevertheless, the variability in effect sizes between studies is large and the role of possible confounding factors such as neurocognitive functions and clinical variables has not been established conclusively. Also, differential patterns of impairment might exist depending on task area (cognitive or affective) and task modality (verbal or visual). In the present study, we aimed to exclusively examine the performance of euthymic bipolar patients in visual cognitive and affective theory of mind in comparison to healthy subjects, as deficits in those domains have been less consistently shown for remitted than for acute patients (Kerr et al. 2003; Ioannidi et al. 2015; Olley et al. 2005). Contrary to our hypotheses, patients did not differ in a statistically significant way from controls on our measures of visual cognitive and visual affective ToM. Also in disagreement with our hypotheses, we did not find statistically significant differences between patients and controls regarding their time taken to complete either of the ToM tasks. In terms of effect sizes, our findings were also below the effect sizes reported in recent meta-analyses. While Samamé et al. (2015) have reported effect sizes in the small-to-medium range for cognitive ToM, and Bora et al. (2016) have reported effect sizes in the moderate range pooling across ToM tasks, we observed only a small effect in favor of controls on the performance of our cognitive ToM task. On our visual affective ToM task, there was even a small effect favoring the performance of patients. With respect to ToM task completion time, we found controls to be faster than patients with a small effect size on the cognitive ToM task. A large effect in favor of controls was found for the time taken to complete the affective ToM task.