Suicide attempts: Patients with and without an affective disorder show impaired autobiographical memory specificity

Abstract

A number of studies have shown reduced recall of specific autobiographical memories (AMs) in patients after attempted suicide, but in all of them the study samples were confounded with diagnoses of affective disorders. The present study aims to demonstrate impaired specific autobiographical memory in patients after a suicide attempt without a diagnosis of an affective disorder. Four groups were compared: (1) patients with an actual major depression and a suicide attempt; (2) patients after a suicide attempt without a lifetime history of an affective diagnosis; (3) patients currently suffering from major depression without a suicide attempt; and (4) control persons not suffering from either of the two conditions during their entire life. Individuals with major depression and a suicide attempt showed reduced specificity of AM and, most importantly, patients with a suicide attempt—despite the absence of an affective disorder—were equally impaired with recall of specific AMs as were patients with major depression. The authors propose that reduced specific AM is a common vulnerability factor that can lead either to the development of an affective disorder and/or to a suicide attempt.

Notes

We thank the Medizinische Forschungsgesellschaft Salzburg for financial support of the study (Grant No. 031095/ho). We also thank the patients for their participation in the study. We further appreciate the invaluable comments made by the reviewers and editor

In the case of an ascertained diagnosis of MD we use the acronym MD+. For convenience of the readers we also use the acronym MD−which, however, refers to the lifetime absence of any affective disorder.

In a 2 (MD: yes, no) × 2 (SA: yes, no) × 2 (Repeated measure: Cue‐valence: positive, negative) ANOVA with the number of specific AMs as the dependent variable we found no significant main effect for cue valence, F(1, 80) = 1.57, p = .21, no significant interactions between cue valence and either MD, F(1, 80) = 0.001, p = .97, or SA, F(1, 80) = 0.005, p = .95, nor a significant three‐way interaction between these factors, F(1, 80) = 0.32, p = .57. Therefore, for further statistical analyses we collapsed the specific responses to the positive cues and to the negative cues into one combined measure for specific AMs.

In addition to this ANOVA we computed a 2 (MD: yes, no) × 2 (SA: yes, no) ANCOVA, controlling for BDI, HRSD and HS. Specificity of AM showed significant main effects for MD, F(1, 77) = 6.82, p = .011, for SA, F(1, 77) = 12.35, p = .001, and a significant interaction between MD and SA, F(1, 77) = 13.77, p = .000. Although partialling severity of depression in this case can be seen as problematic (see Miller & Chapman, 2001), these results further support our view that the reported significant main effects and interactions of the ANOVA ought to be attributed to the group constituencies (Diagnoses, SA), and not to depression level.