BACKGROUND AND OBJECTIVES

Interference from irrelevant negative material might be a key mechanism underlying intrusive ruminative thoughts in depression. Considering commonalities between depression and social anxiety and the presence of similar intrusive thoughts in social anxiety, the current study was designed to assess whether interference from irrelevant material in working memory is specific to depression or is also present in social anxiety disorder.

METHODS

To examine the effects of irrelevant emotional material on working memory performance, participants memorized two lists of words on each trial and were subsequently instructed to ignore one of the lists. Participants were then asked to indicate whether a probe word belonged to the relevant list or not.

RESULTS

Compared to control and social anxiety groups, the depression groups (both pure and comorbid with social anxiety disorder) exhibited greater difficulties removing irrelevant emotional material from working memory (i.e., greater intrusion effects). Greater intrusion effects were also associated with increased rumination.

LIMITATIONS

Although we included three clinical groups (depression, social anxiety, and the comorbid groups), the results are based on a relatively small number of participants.

CONCLUSIONS

The results indicate that difficulties removing irrelevant material from working memory might be unique to depression, and the ability to inhibit irrelevant information is relatively preserved in social anxiety disorder.