Defining reactivity: How several methodological decisions can affect conclusions about emotional reactivity in psychopathology

Abstract

There are many important methodological decisions that need to be made when examining emotional reactivity in psychopathology. In the present study, we examined the effects of two such decisions in an investigation of emotional reactivity in depression: (1) which (if any) comparison condition to employ; and (2) how to define change. Depressed (N = 69) and control (N = 37) participants viewed emotion-inducing film clips while subjective and facial responses were measured. Emotional reactivity was defined using no comparison condition (i.e., raw scores), baseline comparison condition (i.e., no stimulus presented), and neutral comparison condition (i.e., neutral stimulus presented). Change in emotional reactivity was assessed using four analytic approaches: difference scores, percentage change, residualised change, and ANCOVA. Results differed among the three comparison conditions and among several of the analytic approaches. Overall, our investigation suggests that choosing a comparison condition and the definition of change can significantly influence the presence of group differences in emotional reactivity. Recommendations for studies of emotional reactivity in psychopathology are discussed.

Keywords:

• Emotional reactivity
• Depression
• Positive and negative emotions

Acknowledgments

This research was supported by the American Psychological Foundation and Council of Graduate Departments of Psychology Clarence J. Rosecrans Scholarship as well as National Institute of Mental Health Grant F31 MH67309, both awarded to SAS.

Additionally, we would like to thank Jonathan Rottenberg for his assistance and for allowing us to use his self-report emotions questionnaire and standardised movie clips.

Notes

¹A statistically identical approach that is often used is a mixed-design ANOVA with one within-subjects factor (i.e., baseline vs. emotion induction) and one between-subjects factor (i.e., depressed vs. controls).

²A statistically identical approach that is often used is to conduct an ANCOVA with difference scores as the dependent variable and the comparison condition score as the covariate.

³We also examined whether there were any main effects of gender for both subjective and facial responses. Results indicated a main effect of gender for Subjective-Sadness PCS using the baseline comparison condition, F(1, 100) = 4.13, p < .05, with women reporting greater sadness reactivity relative to men. In addition, there was also a main effect of gender for Facial-Fear during the fear film, F(1, 100) = 6.70, p < .05, with men exhibiting more facial fear relative to women.

⁴We conducted additional analyses examining whether depressed participants with comorbid anxiety differed from those with depression only. In general, the results were nearly identical between the two depressed groups, with the only significant difference occurring for Subjective-Sadness difference scores using the neutral comparison condition. Results indicated that participants with depression and a current anxiety disorder had reduced Subjective-Sadness reactivity relative to controls (p < .05), but they did not differ from participants with depression only. We also examined whether depressed participants currently taking medication differed from depressed participants who were medication free. Results indicated that depressed participants currently taking medication had greater Subjective-Happiness reactivity when using the baseline comparison condition for both difference scores (p < .05) and PCSs at a trend level (p < .07). The groups also differed in their raw Subjective-Fear during the neutral film clip, with medicated depressed participants reporting more Subjective-Fear than non-medicated depressed participants at a trend level (p < .06).