LAUSR

BACKGROUND Mood Induction Procedures (MIPs) are used widely in research on cognitive vulnerability to depression. Although empirical evidence supports certain MIPs as effective, little research has evaluated whether MIP-induced sad moods are sufficiently persistent. This study aimed to determine (1) how long an MIP-induced mood lasts according to commonly used operational definitions and (2) whether these findings vary according to the type of MIP used. METHODS Four-hundred-and-one undergraduate students were randomly assigned to one of three commonly used sad MIPs (music, memory, music+memory) or to one of three matched neutral MIPs. Mood was repeatedly measured immediately prior to and following the MIP. RESULTS Results did not support the widely held belief that commonly used MIPs induce a sufficient and persistent sad mood. The memory-related MIPs induced the most persistent sad mood. Based on the majority of operational definitions, however, induced mood effects did not last longer than 4 min, regardless of MIP type. LIMITATIONS Future studies should examine additional factors that may have affected the trajectories observed in the current study (e.g., task completed in between mood measurements) and in vulnerable (e.g., past-depressed) populations. CONCLUSIONS This study constitutes an important first step in validating the use of MIPs in cognitive vulnerability research and provides researchers with important information on future study designs. More important, the study raises doubt about the validity of various conclusions drawn from some MIP studies and calls into question the theoretical conceptualizations of depression that are based on potentially biased results and a possibly incomplete literature.