Supplementary Material for: Meta-Analysis of Neuropsychological Studies in Panic Disorder Patients: Evidence of Impaired Performance during the Emotional Stroop Task

Background: Recent investigations have highlighted significant differences in verbal recall between patients with panic disorder (PD) and controls. These studies have highlighted that verbal memory and working memory could be impaired in PD. Objectives: The objective of the present meta-analysis is to confirm this hypothesis, reviewing the studies that have investigated neurocognitive testing in PD. Methods: We performed a systematic literature search for studies published between 1980 and 2015 that reported cognitive measurements in PD patients and controls. Effect size estimates were computed using the restricted maximum likelihood model. Only case-control studies were selected for this meta-analysis. We included studies that made a direct comparison between PD subjects and healthy controls. The diagnostic group consisted of adult patients aged over 18 years diagnosed with PD. We excluded the studies that did not employ a case-control design. All statistical analyses were carried out on R using the “metafor” package version 1.9-8. The effect size for each study neuropsychological test was calculated using the mean and SD of performance results, and p values < 0.05 were considered significant. Results: We identified few studies that tested verbal memory and executive functions in PD patients and controls, and this difference was not significant. On the other hand, there are several studies that have used the emotional Stroop task to assess cognitive functions in PD. There is no robust evidence of impairment of memory function in PD; however, when considering the emotional Stroop task, it was found that PD patients performed slower (p < 0.01) than healthy controls for all three types of stimuli (neutral, negative, positive). Conclusion: This meta-analysis included a small number of studies, which may have introduced bias into the analysis. However, there is some evidence of impairment of neurocognitive functions in PD when performing the emotional Stroop task. Furthermore, the paucity of studies evaluating neurocognition in PD suggests the need for further research in this field in order to draw meaningful conclusions.