There are many types of personality disorders and each one has different symptoms and characteristics. Some characteristics are shared by different disorders. People who rebel against their culture or society or who have outbursts and rages or have trouble with social skills, how they see themselves, how they cope with being around other people, and how they control their impulses are characteristics all shared by those who suffer from personality disorders. Many people who suffer from one disorder usually suffer more than one at a time but do not believe that they have a problem. It is said that, "Symptoms stem from basic personality traits that develop over a period of time."(Mental Health) There are a few basic treatments for people with personality disorders that work for some, but not for others. Psychodynamic psychotherapy, or psychoanalytical therapy, focuses on past events and long repressed feelings. Psychodynamic models integrate the past with the patient's current life. Behavior therapy is used to teach different kinds of social skills. Cognitive therapy concentrates on changing of negative thinking. Cognitive-behavioral therapy combines cognitive and behavioral therapy techniques. Personality disorders affect ten to fifteen percent of the population. Some affect certain populations more than others. Studies have suggested that biology plays a part in these disorders. Personality disorders can be inherited from generation to generation and are a primary result of the person's experience during childhood and adolescence. Borderline Personality Disorder is the most common personality disorder and affects approximately 2% of the population (Mental Health). Those that suffer from this disorder may experience brief periods in which they separate from reality and often are diagnosed with depression and psychotic disorders. They are unstable in personal relationships and have an unstable self-image and emotions and have little control over impulses.