The experience of grief and loss involves a variety of trajectories and responses, including feelings of shock or disbelief, somatic symptoms, longing for the loved one and avoidance behaviours, as well as positive reactions such as post-traumatic growth or meaning-making. Despite the large number of psychometric instruments available for assessing the pathological dimensions of grief, few tools address the different responses to bereavement.

The aim of this research was to develop and test the psychometric properties (factorial structure, reliability and validity) of an instrument based on the Integrative-Relational Model of grief and designed to address the grief responses (the Grief Response Scale (GRS)) in a clinical sample of participants who had experienced bereavement.

In total, 379 participants were recruited from different clinics in Spain. Each participant completed a self-report questionnaire including the GRS and measures of complicated grief, post-traumatic stress disorder, depression, anxiety and post-traumatic growth. Twenty-eight clinical psychologists contacted each of the participants individually in order to carry out the assessment.

Exploratory factor and item analysis yielded a six-factor solution for the GRS, including symptomatological distress, avoidance orientation, loss orientation, positive changes, loss integration and social support. Reliability values ranged from ω =.88 for the symptomatological distress subscale to ω= .65 for the loss orientation subscale. We assessed validity evidence using Pearson's correlations, which showed significant positive and negative associations depending on the subscale. we also found statistically significant differences between participants who met the criteria for complicated grief (ICG≥30) and those who did not.

The GRS appears to be a suitable tool for assessing the range of grief responses in a clinical population. It can measure both complicated and pathological reactions to grief, as well as positive outcomes. The GRS may also be useful for clinicians working with bereavement and end-of-life situations.