Voluntary suppression of thoughts is influenced by anxious and ruminative tendencies in healthy volunteers.

Replicating thought suppression effects with the Think/No-Think paradigm (TNT) has failed in some studies investigating the phenomenon of below-baseline recall of suppressed stimuli. Attempts have been made to isolate factors that might explain inter-individual differences in suppression performance. Certain personality traits, whether associated with a pathological state or investigated in a community sample, have been shown to interfere with successful thought suppression and might be responsible for some of the negative results obtained in TNT studies. In the present study we investigate the influence of psychometric measures of depression and anxiety in a fairly large sample of healthy volunteers. We show that high brooding and anxious tendencies predict worse suppression performance. While no suppression was shown when investigating the TNT not taking the psychometric measures into account, including these two traits in the analysis resulted in a pattern of below-baseline recall only for low brooders and low anxious participants. We argue that inclusion of variables measuring personality traits is warranted using the TNT and that these variables already exert their influence at minimal levels of variance, significantly improving the interpretability of the results. Future research should therefore cautiously investigate potential confounding personality characteristics before analysing their data.