Validation of the Italian version Inventory of Complicated Grief (ICG): a study comparing CG patients versus bipolar disorder, PTSD and healthy controls

Abstract

Background: A minority (9%-20%) of bereaved individuals experience symptoms of persistent intense grief associated with significant distress and impairment. This recently identified distinct post-loss syndrome has been variously named complicated grief, prolonged grief disorder, traumatic grief and persistent complex bereavement disorder. The Inventory of Complicated Grief (ICG) is a self-report instrument used to reliably identify this syndrome. We undertook a study to: 1) validate the Italian version of the ICG; 2) examine its performance in a clinical of bereaved individuals with complicated grief, post-traumatic stress disorder, bipolar disorder and healthy controls.

Methods: Study participants included 171 bereaved individuals clinically diagnosed with complicated grief (n=64); post-traumatic stress disorder (n=72); bipolar disorder (n=35) and 58 bereaved healthy controls. Assessments included the Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I/P) and the Italian version of the ICG.

Results: The mean total ICG score was significantly different among the study groups [F(3.228)=94.19, p<.001]. Post-hoc Games-Howell comparisons indicated significantly higher scores in complicated grief patients with respect to the other three groups and significantly lower scores in healthy controls compared to all other participants. The scale demonstrated a high level of internal consistency: Cronbach's alpha value for the whole sample was 0.947. Factor analyses demonstrated a single-factor solution.

Conclusions: This study provides evidence of the validation of the Italian version of the ICG, tested in a large and well-characterized clinical help-seeking population. These data further support the existence of a unique grief-related syndrome different from bipolar and post-traumatic stress disorders.