There is a high prevalence of depressive symptoms among adults with a history of childhood trauma. A negative bias is implicated in depressive symptomatology and has also been found within physically abused children, who show preferential processing of anger. However, how these biases mediate the causal link between childhood trauma and adult depression has not yet been clarified.

The study involved a total of 71 participants in a cross sectional study of depressed patients and healthy individuals, subdivided into those with and without a history of childhood trauma. They completed a facial emotion recognition task to assess their efficiency in processing a variety of emotions.

Healthy individuals with a history of childhood trauma made significantly more errors in recognising negative emotions (fear, anger and sadness) but fewer errors in recognizing positive emotion (happiness) than those without childhood trauma. An opposite pattern was found in the group of depressed patients. In addition, the severity of physical abuse was positively correlated with the speed to process anger in healthy individuals with a history of childhood trauma.

Resilient individuals - those with a history of childhood trauma but not depression - display positively-biased emotion recognition, which we suggest helps explain why they do not manifest depressive symptoms despite their early experiences of childhood trauma. In contrast, other individuals who become vulnerable to depression after childhood trauma show an amplified bias towards negative emotion. Thus, these enduring individual differences in emotional processing may differentially influence the pathogenesis of depression as a function of childhood trauma.