Measuring Intrusive Prospective Imagery using the Impact of Future Events Scale (IFES): Psychometric properties and relation to risk for Bipolar Disorder

Abstract

We define intrusive prospective imagery as the experience of mental imagery of events that may happen in the future and which come to mind involuntarily. This everyday phenomenon may be exacerbated in psychological disorders such as bipolar disorder (Holmes, Geddes, Colom, & Goodwin, 2008) although specific measures to assess this have been lacking. We recently developed the Impact of Future Events Scale (IFES; Deeprose & Holmes, 2010), which is further examined in the current paper. In Study 1, adults volunteers (N=50) completed the IFES on two occasions, with 1-week between measurements. This revealed acceptable test-rest reliability. In Study 2, (N=90) IFES showed good internal consistency and confirmed two predictions. First, in the total sample risk for bipolar disorder (MDQ; Hirschfield et al., 2000) and IFES Total Score correlated positively. Second, when the sample was split into high (MDQ ≥ 7) and low (MDQ ≤ 6) bipolarity risk groups, higher IFES Total Scores were observed in the high risk group. We conclude that 1) IFES presents a useful measure for assessing intrusive prospective imagery with acceptable test-retest reliability and good internal consistency and 2) risk for bipolar disorder is associated with elevated IFES Total Scores with potentially important clinical implications.