Many of these therapy approaches (especially Brainspotting) help clients desensitize and reprocess traumas, negative life experiences and messages. Clients are able to create more positive beliefs about themselves, be less reactive in relationships, as well as more conscious and intentional in their behavior. This results in improved overall confidence and security.
Note: Even though I may start with an individual, I often see the need to include other family or significant others in sessions. My belief is that a symptom or behavior is often just a small part of a larger system with many interacting pieces.