Psychological Reports, 1998,82,783-793. Q Psychological Reports 1998 THE POSITIVE AND NEGATIVE SUICIDE IDEATION INVENTORY: DEVELOPMENT AND VALIDATION ' AUGUSTINE OSMAN PETER M. GUTIEKREZ University of Northern Iowa h'orthenr Illinois University BEVERLY A. KOPPER, l%WCISCO X. BARRIOS, CHRISTINE E. CHIROS University of Northern Iowa Summary.-We conducted two studies to develop and vahdate a brief self-repon measure for assessing the frequency of positive and negative thoughts related to sui- cidal behavior Items on this new measure, the Positive and Negative Suicide Ideation inventory, wcrc generated by undergraduates. In Study 1, we administered a 20-item version of the lnvcnrory to 150 male and 300 female undergraduates and conducted an exploratory principal axis factor analysis with varimax rotation. Two factors, Posi- tive Ideation and Negative Ideation, were retained. In Study 2, we conducted a confir- matory factor analysis to validate the fit of the one-facror and the oblique nvo-factor models to data from another sample of 84 men and 202 women. The oblique nvo-fac- tor model provided an excellent fit to h e sample data. We also examined preliminary evidence of concurrent and predictive validity. Over-all, these Find~ngs suggested that the inventory is a well-developed self-report measure for assessing the frequency of positive and negative thoughts related to suicidal behavior. The rates of suicidal ideation and attempts among adolescents and young adults, ages 15 to 25 years, have increased substantially during the past decade (Clark, 1993; United States Department of Health and Human Services, 1994). Several studles have identified a variety of positive, e.g., sat- isfaction with Me, and negative, e.g., conhct with significant others, factors for the high prevalence and incidence rates of suicidal ideation and attempts seen recently in adolescent and young adult populations (Adarns, Overhos- ler, & Lehnert, 1994; Lewinsohn, Rohde, & Seeley, 1996; Linehan, Good- stein, Nielsen, & Chiles, 1983). To date, however, there is only one published self-report measure de- signed specifically for tapping both the positive and negative thoughts re- lated to suicidal attempts. Orbach, Wstein, Har-Even, Apter, Tiano, and Elizur (1991) developed the Multi-Attitude Suicide Tendency scale for assess- ing attitudes toward and repulsion by life and death. The measure was de- veloped and validated for use with young Israeli adolescents. Findings from 'This project was funded in part by pro'ect grants from the Graduate College and the Depart- ment of Psychology, University of ~ o d e r n Iowa. Address correspondence to Augustine Os- man or any of these authors, Department of Psychology, University of Northern Iowa, 334 Baker Hall, Cedar Falls, Iowa 50614-0505 or e-mail via Internet (augustine.osman@uni.edu).