Going a step beyond irritability is hostility, which is defined as a person with depression who expresses anger outwardly. Most often hostile-depression gets expressed towards other people or about external issues in the environment.
Sometimes a child or adult will outwardly be aggressive toward a friend or family member, attacking others for their opinions, thoughts or more materialistic things like how they dress, look, etc. Hostility tends to develop in individuals who’ve experienced trauma from their environment.
They mistrust others and feel hopeless and helpless about the world around them. This insecurity doesn’t present in a quiet depressive restlessness, but rather an external demanding, cynical and negativistic style. Studies have found that depressed children and adults who have experienced loss may have higher rates of hostility.