To answer your question, we first need to know what borderline personality disorder is. What is BPD? Borderline Personality Disorder: Borderline Personality Disorder (BPD) is a complex mental health condition characterized by a pattern of ongoing instability in moods, behavior, self-image, and functioning. These experiences often result in impulsive actions and problematic relationships. Here are key features and symptoms associated with BPD: Self-Harm and Suicidal Behavior Emotional Instability: People with BPD often experience intense episodes of anger, depression, and anxiety Distorted Self-Image: They often have an unstable sense of self and identity, often resulting in sudden changes in values, goals, and vocational aspirations Fear of Abandonment: They have often an intense fear of abandonment or rejection, which can lead to frantic efforts to avoid real or imagined separation or rejection Unstable Relationships: Relationships are often intense and unstable, swinging between extremes of idealization (intense closeness and love) and devaluation (intense dislike or anger) Impulsive Behaviors such as excessive spending, unsafe sex, substance abuse, reckless driving, or binge eating Chronic Feelings of Emptiness Stress-related paranoid thoughts or severe dissociative symptoms, such as feeling cut off from oneself or seeing oneself from outside one's body In my opinion, I think that there are many similarities between stuttering and personality disorders. Like, Yaruss (PhD researcher) found that there is a very high suicidal ideation rate among people who stutter - 67.9% in [a research study](https://www.reddit.com/r/Stutter/comments/16o8l2l/participate_in_stuttering_research_exploring_the/) I also think that stuttering and borderline personality disorder can be associated with childhood trauma. I mean like experiencing bullying, social pressure/rejection etc. This can lead to (emotional) stress and social anxiety and avoidance behaviors. So, I'd say that psychological impact of stuttering might indeed contribute to developing mental health issues such as you pointed out: a personality disorder