Antisocial personality disorder (APD) is a personality disorder which is often characterised by antisocial and impulsive behaviour. APD is generally (if controversially) considered to be the same as, or similar to, the disorder that was previously known as psychopathic or sociopathic personality disorder. Approximately 3% of men and 1% of women have some form of antisocial personality disorder (source: DSM-IV).

Avoidant personality disorder (sometimes abbreviated APD or AvPD) is a personality disorder characterised by a pervasive pattern of social inhibition, feelings of inadequacy, and extreme sensitivity to negative evaluation. People with avoidant personality disorder often consider themselves to be socially inept or personally unappealing, and avoid social interaction for fear of being ridiculed or humiliated.

In psychiatry, borderline personality disorder (BPD) is characterized by extreme 'black and white' thinking, mood swings, emotional reasoning, disrupted relationships and difficulty in functioning in a way society accepts as normal.

Chats and forums dedicated to all personality (DSM Axis II) disorders.

Persons with this disorder rely heavily on others for validation and fulfillment of basic needs. Often unable to properly care for themselves, persons with dependent personality disorder lack self confidence and security, and are deficient in making decisions.

In psychiatry, histrionic personality disorder (HPD) involves a pattern of excessive emotional expression and attention-seeking, including an excessive need for approval and inappropriate seductiveness, that usually begins in early adulthood.

Narcissistic personality disorder (NPD) is a personality disorder that is characterized by extreme feelings of self-importance, a high need for admiration, and a lack of empathy. NPD can be considered as a pathological form of narcissism. It is estimated that 0.7-1% of the general population are afflicted with NPD. Most people with NPD (50-75%, according to the DSM) are men.

Obsessive Compulsive Personality Disorder (OCPD) is a personality disorder that is characterized by a general psychological inflexibility, rigid conformity to rules and procedures, perfectionism, and excessive orderliness.

Paranoid personality disorder is a psychiatric diagnosis that denotes a personality disorder with paranoid features. The use of the term paranoia in this context is not meant to refer to the presence of frank delusions or psychosis, but implies the presence of ongoing, unbased suspiciousness and distrust of people.

Passive-aggressive behavior refers to passive, sometimes obstructionist resistance to authoritative instructions in interpersonal or occupational situations. Sometimes a method of dealing with stress or frustration, it results in the person attacking other people in subtle, indirect, and seemingly passive ways.

Schizotypal personality disorder is a personality disorder that is characterized by a need for social isolation, odd behaviour and thinking, and often unconventional beliefs such as being convinced of having extra sensory abilities. Some people believe that schizotypal personality disorder is a mild form of schizophrenia.