Borderline personality disorder
People with BPD are easily bored and it is hard for them to concentrate. People with BPD may tend to disconnect or "dissociate" from people and things around them, which can be thought of as an intense form of "zoning out". This often happens in response to a painful event, or something that triggers the memory of a painful event. This can give make the person feel better for a short time, it can also have the unwanted side effect of blocking ordinary feelings. This has the result of keeping people with BPD from learning how to handle these feelings, and can make it difficult for them to make positive choices when they feel these emotions. Sometimes other people can see when someone with BPD is dissociating because the expressions in their voice or face can seem emotionless, or they look like they are distracted. Sometimes when someone with BPD is dissociating, other people are not able to see or know that it is happening.