Assessment of anhedonia in psychological trauma: psychometric and neuroimaging perspectives

Symptoms of anhedonia, or deficits in the ability to experience positive affect, are increasingly recognized as an outcome of traumatic stress including in individuals with PTSD. However, little research has investigated negative affective responses to what would normally be considered pleasant events (e.g., receiving a compliment or gift, physical affection) in traumatized persons. We demonstrate not only self-reported decreased positive affect but also increased negative affect in response to positive events in 55 women with PTSD, in comparison with 35 women without PTSD, via their response to a Hedonic Deficit & Interference Scale (HDIS). The HDIS demonstrated strong internal validity, convergent and incremental validity relative to other measures of anhedonia, and discriminant validity in relation to depression versus anxiety symptoms in this sample. In addition, in response to imagery of social versus non-social positive events, HDIS scores predicted self-report positive and negative affective responses. In a sub-sample of participants completing the imagery task while undergoing fMRI (n=12), HDIS scores also predicted BOLD response within the left orbitofrontal cortex, ventromedial prefrontal cortex, amygdala, and cerebellum. Future research and clinical directions are discussed.