Self-Discrepancy Theory: This theory is about how people compare themselves. It looks at the differences between how we see ourselves, how we want to see ourselves, and how we think others see us. When there's a big gap between these views, it can make us feel bad or anxious. The idea is to integrate those parts into a coherent whole to feel less anxious about identity disturbance issues.

Emotional Cascade Model: The idea is that one bad thought leads to another, and it starts a chain reaction, like dominoes falling, making emotions more intense. This model tries to explain how this happens, especially in people with Borderline Personality Disorder (BPD), leading them to feel overwhelmed by their emotions, so they may act out in self-destructive ways (ie. self-harm).

Interpersonal Emotion Regulation: This is about how we manage our emotions through interactions with others. For example, talking to a friend when we're feeling down can help us feel better. It looks at how this process works and how it can sometimes go wrong. People with BPD (and other personality disorders) sometimes do not know how to regulate their emotions on their own, so they use others to do it.

Rejection Sensitivity: This is the tendency to easily feel rejected or believe that others don't want us around. Some people with personality disorders are very sensitive to rejection and might act in maladaptive ways to cope with it.

Psychodynamic Theory/Treatments: This is a big area of psychology that believes our past experiences, especially those from childhood, shape our personality and how we deal with emotions.

Object Relations Theory: This part of psychodynamic theory focuses on relationships, particularly how our early relationships with caregivers shape how we relate to others later in life. It suggests our first relationships act as templates for later ones.

Transference-Focused Therapy (TFT): This therapy focuses on the relationship between the therapist and the patient. It uses the patient's feelings towards the therapist as a way to understand and work through issues from past relationships.

Mentalization-Based Therapy (MBT): This therapy helps people better understand their own thoughts and feelings and those of others around them. It's especially used for BPD and focuses on improving emotional awareness and regulation.