Depression, a multifaceted mental health disorder, is often associated with negative cognitive biases such as hostile attributions (HA). However, the borderline pattern, with its characteristic emotional dysregulation and complex interpersonal interactions, may have a significant role in this relationship. To better understand these associations, we analyzed data from two research studies. The first study, based on a reanalysis of data from a previous study conducted on the general population (N = 54), utilized electroencephalography (EEG) alongside the Personality Assessment Inventory Borderline Features (PAI-BOR) Scale. The second study (N = 189), conducted on the general population and prisoners, focused on negative affectivity and disinhibition, two domains of personality pathology that characterize borderline pattern. Results from both studies revealed a link between depression and HA, with features/domains of borderline pattern emerging as a key predictor of HA. Additionally, apart from negative affectivity, detachment predicted hostile attribution, and, not as hypothesized, disinhibition. Our findings suggest that in investigating hostile attributions, it is more important to consider depressive tendencies stemming from underlying personality pathology (i.e., borderline patterns) rather than mere symptoms of depression.