An Examination of the Glover Numbing Scale: Expanding the Content Validity of Posttraumatic Numbing

  • Joshua D. Clapp
  • J. Gayle Beck


Quantification of posttraumatic numbing (PTN) has largely been limited to the assessment of a small number of items taken directly from the DSM. The current study takes steps to expand the content validity of PTN through examination of the Glover Numbing Scale (GNS), one of the few available measures specific to PTN. Specifically, the factor structure of the GNS and its convergence with DSM-based indices of PTN were examined in a sample of motor vehicle accident survivors (MVA; N = 288). Whereas the 5-factor structure originally proposed by Glover et al. Anxiety 1:70–79 (1994) evidenced a poor fit to the sample data, exploratory analysis suggested a 1-factor structure underlying data collected from the sample. Furthermore, GNS scores derived from this solution evidenced a strong convergent relationship with DSM-based PTN. These data suggest that alternative indicators contained within the GNS may be used to expand current conceptualizations of PTN.


Posttraumatic numbing Trauma GNS MVA 


  1. American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington DC: Author.Google Scholar
  2. Anastasi, A. (1988). Psychological testing (6th ed.). New York: Macmillan.Google Scholar
  3. Blake, D. D., Weathers, F. W., Nagy, L. M., Kaloupek, D. G., Klauminzer, G., Charney, D. S., et al. (1990). Clinician-administered PTSD scale (CAPS). Boston, MA: National Center for Post-traumatic Stress Disorder, Behavioral Science Division.Google Scholar
  4. Blanchard, E. B., & Hickling, E. J. (1997). After the crash. Washington, DC: American Psychological Association.Google Scholar
  5. Brewin, C. R., Dalgleish, T., & Joseph, S. (1996). A dual representation theory of posttraumatic stress disorder. Psychological Review, 103, 670–686.PubMedCrossRefGoogle Scholar
  6. Brewin, C. R., Andrews, B., & Valentine, J. D. (2000). Meta-analysis of risk factors for posttraumatic stress disorder in trauma-exposed adults. Journal of Consulting and Clinical Psychology, 68, 748–766.PubMedCrossRefGoogle Scholar
  7. Clapp, J. D., Beck, J. G., Palyo, S. A., & Grant, D. M. (2008). An examination of the synergy of pain and PTSD on quality of life: Additive or multiplicative effects? Pain, 138, 301–309.PubMedCrossRefGoogle Scholar
  8. Comrey, A. L., & Lee, H. B. (1992). A first course in factor analysis (2nd ed). Hillsdale, NJ: Lawrence Erlbaum Associates.Google Scholar
  9. Ehlers, A., & Clark, D. M. (2000). A cognitive model of posttraumatic stress disorder. Behaviour Research and Therapy, 38, 319–345.PubMedCrossRefGoogle Scholar
  10. Feeny, N. C., Zoellner, L. A., Fitzgibbons, L. A., & Foa, E. B. (2000). Exploring the roles of emotional numbing, depression, and dissociation in PTSD. Journal of Traumatic Stress, 13, 489–498.PubMedCrossRefGoogle Scholar
  11. First, M. B., Spitzer, R. L., Gibbon, M., & Williams, J. B. W. (1995). Structured interview for DSM-IV Axis I Disorders: Patient edition (SCID I/P). New York: New York State Psychiatric Institute, Biometrics Department.Google Scholar
  12. Flack, W. F., Litz, B. T., Hsieh, F. Y., Kaloupek, D. G., & Keane, T. M. (2000). Predictors of emotional numbing revisited: A replication and extension. Journal of Traumatic Stress, 13, 611–618.PubMedCrossRefGoogle Scholar
  13. Foa, E. B., Steketee, G., & Rothbaum, B. O. (1989). Behavioral/cognitive conceptualizations of post-traumatic stress disorder. Behavior Therapy, 20, 155–176.CrossRefGoogle Scholar
  14. Foa, E. B., Zinbarg, R., & Rothbaum, B. O. (1992). Uncontrollability and unpredictability in post-traumatic stress disorder: An animal model. Psychological Bulletin, 112, 218–238.PubMedCrossRefGoogle Scholar
  15. Folstein, M. F., Folstein, S. E., & McHugh, P. R. (1975). “Mini-mental state” A practical method for grading the cognitive state of patients for the clinician. Journal of Psychiatric Research, 12, 189–198.PubMedCrossRefGoogle Scholar
  16. Glover, H. (1992). Emotional numbing: A possible endorphin-mediated phenomenon associated with post-traumatic stress disorders and other allied psychopathologic states. Journal of Traumatic Stress, 5, 643–675.CrossRefGoogle Scholar
  17. Glover, H., Ohlde, C., Silver, S., Packard, P., Goodnick, P., & Hamlin, C. L. (1994). The numbing scale: Psychometric properties, a preliminary report. Anxiety, 1, 70–79.PubMedGoogle Scholar
  18. Harris, R. E. & Lingoes, J. C. (1955). Subscales for the MMPI: An aid to profile interpretation. Unpublished manuscript, University of California.Google Scholar
  19. Harvey, A. G., & Bryant, R. A. (1998). The relationship between acute stress disorder and posttraumatic stress disorder: A prospective evaluation of motor vehicle accident survivors. Journal of Consulting and Clinical Psychology, 66, 507–512.PubMedCrossRefGoogle Scholar
  20. Haynes, S. N., Richard, D. C. S., & Kubany, E. S. (1995). Content validity in psychological assessment: A functional approach to concept and methods. Psychological Assessment, 7, 238–247.CrossRefGoogle Scholar
  21. Horn, J. L. (1965). A rationale and test for the number of factors in factor analysis. Psychometrika, 30, 179–185.PubMedCrossRefGoogle Scholar
  22. Hu, L., & Bentler, P. M. (1999). Cutoff criteria for fit indices in covariance structure analysis: Conventional criteria versus new alternatives. Structural Equation Modeling, 6, 1–55.CrossRefGoogle Scholar
  23. Keane, T. M., Caddell, J. M., & Taylor, K. L. (1988). Mississippi Scale for Combat-Related Post-Traumatic Stress Disorder: Three studies in reliability and validity. Journal of Consulting and Clinical Psychology, 56, 85–90.PubMedCrossRefGoogle Scholar
  24. Keane, T. M., Malloy, P. F., & Fairbank, J. A. (1984). Empirical development of an MMPI subscale for the assessment of combat-related posttraumatic stress disorder. Journal of Consulting and Clinical Psychology, 52, 888–891.PubMedCrossRefGoogle Scholar
  25. King, D. W., Leskin, G. A., King, L. A., & Weathers, F. W. (1998). Confirmatory factor analysis of the Clinician-Administered PTSD Scale: Evidence for the dimensionality of posttraumatic stress disorder. Psychological Assessment, 10, 90–96.CrossRefGoogle Scholar
  26. Kline, R. B. (2005). Principals and practice of structural equation modeling (2nd ed).. New York: Guilford.Google Scholar
  27. Kuhn, E., Blanchard, E. B., & Hickling, E. J. (2003). Posttraumatic stress disorder and psychosocial functioning within two samples of MVA survivors. Behaviour Research and Therapy, 41, 1105–1112.PubMedCrossRefGoogle Scholar
  28. Litz, B. T. (1992). Emotional numbing in combat-related post-traumatic stress disorder: A critical review and reformulation. Clinical Psychology Review, 12, 417–432.CrossRefGoogle Scholar
  29. Litz, B. T., & Gray, M. J. (2002). Emotional numbing in posttraumatic stress disorder: Current and future directions. Australian and New Zealand Journal of Psychiatry, 36, 198–204.PubMedCrossRefGoogle Scholar
  30. Litz, B. T., Schlenger, W. E., Weathers, F. W., Caddell, J. M., Fairbank, J. A., & LaVange, L. M. (1997). Predictors of emotional numbing in posttraumatic stress disorder. Journal of Traumatic Stress, 10, 607–618.PubMedGoogle Scholar
  31. MacCallum, R. C., Browne, M. W., & Sugawara, H. M. (1996). Power analysis and determination of sample size for covariance structure modeling. Psychological Methods, 1, 130–149.CrossRefGoogle Scholar
  32. McWilliams, L. A., Cox, B. J., & Asmundson, G. J. G. (2005). Symptom structure of posttraumatic stress disorder in a nationally representative sample. Journal of Anxiety Disorders, 19, 626 – 641.PubMedCrossRefGoogle Scholar
  33. Neill, J. J., & Dunn, O. J. (1975). Equality of dependant correlation coefficients. Biometrics, 31, 531–543.CrossRefGoogle Scholar
  34. Norris, F. H. (1992). Epidemiology of trauma: Frequency and impact of different potentially traumatic events on different demographic groups. Journal of Consulting and Clinical Psychology, 60, 409–418.PubMedCrossRefGoogle Scholar
  35. Palyo, S. A., Clapp, J. D., Beck, J. G., Grant, D. M., & Miller, L. M. (2008). Unpacking the relationship between posttraumatic numbing and hyperarousal in a sample of help-seeking motor vehicle accident survivors: Replication and extension. Journal of Traumatic Stress, 21, 235–238.PubMedCrossRefGoogle Scholar
  36. Pitman, R. K., van der Kolk, B. A., Orr, S. P., & Greenberg, M. S. (1990). Naloxone-reversible analgesic response to combat-related stimuli in posttraumatic stress disorder. A pilot study. Archives of General Psychiatry, 47, 541 – 544.PubMedGoogle Scholar
  37. Ramirez, S. M., Glover, H., Ohlde, C., Mercer, R., Goodnick, P., Hamlin, C., et al. (2001). Relationship of numbing to alexithymia, apathy, and depression. Psychological Reports, 88, 189–200.PubMedCrossRefGoogle Scholar
  38. Riggs, D. S., Byrne, C. A., Weathers, F. W., & Litz, B. T. (1998). The quality of relationships of male Vietnam veterans: Problems associated with posttraumatic stress disorder. Journal of Traumatic Stress, 11, 87–101.PubMedCrossRefGoogle Scholar
  39. Samper, R. E., Taft, C. T., King, D. W., & King, L. A. (2004). Posttraumatic stress disorder symptoms and parenting satisfaction among a national sample of male Vietnam veterans. Journal of Traumatic Stress, 17, 311–315.PubMedCrossRefGoogle Scholar
  40. Steiger, J. (1980). Tests for comparing elements of a correlation matrix. Psychological Bulletin, 87, 245–251.CrossRefGoogle Scholar
  41. Tabachnick, B. G., & Fidell, L. S. (2001). Using multivariate statistics (4th ed). Needham Heights, MA: Allyn & Bacon.Google Scholar
  42. van der Kolk, B., Greenberg, M., Boyd, H., & Krystal, J. (1985). Inescapable shock, neurotransmitters, and addiction to trauma: Toward a psychobiology of post-traumatic stress. Biological Psychiatry(20), 314–325.Google Scholar
  43. Weathers, F. W., Keane, T. R., & Davidson, J. R. T. (2001). Clinician Administered PTSD Scale: A review of the first ten years of research. Depression and Anxiety, 13, 132–156.PubMedCrossRefGoogle Scholar
  44. Wiggins, J. S., Goldberg, L. R., & Applebaum, M. (1971). MMPI Content Scales: Interpretive norms and correlations with other scales. Journal of Consulting and Clinical Psychology, 37, 403–410.CrossRefGoogle Scholar
  45. Williams, E. J. (1959). The comparison of regression variables. Journal of the Royal Statistical Society, Series B, 21, 396–399.Google Scholar
  46. Zwick, W. R., & Velicer, W. F. (1986). Comparison of five rules for determining the number of components to retain. Psychological Bulletin, 99, 432–442.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Department of PsychologyState University of New York at BuffaloBuffaloUSA
  2. 2.Department of PsychologyUniversity of MemphisMemphisUSA

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