Mental illness can interfere with a person's ability to communicate thoughts, feelings, and desires, which can put a severe strain on relationships.
Mental illnesses like depression and anxiety can occur. This can lead to erratic behavior and make it difficult for people to relate to each other. Due to which relationships may sour.
Mental illness also affects the ability to trust others. Because it makes it difficult to read social cues and understand other people's intentions.
Mental illness can be a source of immense stress for both the sufferer and their loved ones. Too much stress can lead to fatigue, burnout, and difficulty focusing on the relationship.
Mental illness can lead to serious self-image issues, making it difficult for people to connect with others and form healthy relationships.