The InterSePT scale for suicidal thinking reliability and validity

J. P. Lindenmayer*, Pal Czobor, Larry Alphs, Ann Marie Nathan, Ravi Anand, Zahur Islam, James C Y Chou, Saide Altinsan, Siemion Altman, Likiana Avigo, Richard Balon, Vanda Beněsová, Luis Bengochea, Alberto Bertoldi, Elisabeth Bokowska, Marc Bourgeois, Bernardo Carpiniello, James Chou, Guy Chouinard, Libor ChvilaJean Dalery, Liliana Dell'Osso, Carl Eisdorfer, Robin A. Emsley, T. A. Fahy, Vera Folnegovic, Sophie Frangou, Pedro Gargoloff, Alberto Giannelli, Alan I. Green, Richard Greenberg, George T. Grossberg, George Hsu, Naveed Iqbal, Miro Jakovljevic, Richard C. Josiassen, Akos Kassaifarkas, Frederic Khidichian, Mary Ann Knesevich, Jack Krasuski, Veronica Larach, Michael Lesem, Pierre Michel Llorca, Jean Pierre Lindenmayer, Stephen Martin, Muriel Maurel-Raymondet, Herbert Meltzer, Laszlo Mod, Eva Morik, Carlos Morra, Ann Mortimer, Gyorgy Ostorharics-Horvath, Ivo Paclt, Jorg J. Pahl, Jeffrey Lee Peters, Rosario Piolo, Michael G. Plopper, Thomas Posever, Delbert Robinson, Carlo Andrea Robotti, Oladapo Tomori, Santha Vaidain, Zdèoka Vyhnándová, Marie Agathe Zimmerman

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

96 Scopus citations


Background: The InterSePT Scale for Suicidal Thinking (ISST) is a 12-item instrument for the assessment of current suicidal ideation in patients with schizophrenia and schizoaffective disorders. We report the psychometric characteristics of this new scale based on two studies. Method: In Study 1, 22 inpatients with schizophrenia and schizoaffective disorders, who had recently attempted suicide or engaged in suicidal ideation, were rated by three trained independent raters to examine interrater reliability. In Study 2, a total of 980 patients with schizophrenia or schizoaffective disorder with a history of suicidal ideation in the past 36 months were enrolled in a 2-year industry-sponsored suicide prevention study. At baseline, these patients were administered the ISST and the Clinical Global Impression Scale for Severity of Suicidality (CGI-SS) by the Principal Investigator (PI) and by a blinded rater (BR), who also administered the Positive and Negative Symptom Scale (PANSS), the Calgary Depression Scale (CDS), and the Scale of Functioning (SOF). Indices of internal reliability, construct and discriminant validity were examined. Results: The intraclass correlation coefficient (ICC) for the total ISST score for the 22 subjects in Study 1 was 0.90 and mean weighted item kappa coefficients ranged from 0.66 to 0.92. In Study 2, internal reliability (Cronbach alpha) was high, ranging from 0.86 to 0.89 for the individual items, and the overall Cronbach alpha coefficient for all items was 0.88. The ISST (PI) total score was highly correlated with the CGI-SS by the blind rater (r=0.61, p<0.0001). ISST total scores significantly differentiated the different levels of CGI-SS (F=519.2; p<0.0001). Results of construct and discriminant validity analyses are also presented. Conclusion: The ISST is a reliable and valid instrument for the assessment of current suicidal thinking in patients with schizophrenia and schizoaffective disorder by both clinicians and researchers.

Original languageEnglish (US)
Pages (from-to)161-170
Number of pages10
JournalSchizophrenia Research
Issue number1-2
StatePublished - Sep 1 2003


  • ISST
  • Schizoaffective disorder
  • Schizophrenia
  • Suicidal ideation

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Biological Psychiatry


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