Personality disorders cause people to experience feelings, thoughts and behaviour patterns that interfere with their daily lives; create problems at home, work or school; and cause problems in their personal, social and professional relationships and interactions with others. Most people go through periods in their lives when they experience such thoughts, feelings and behaviour. A personality disorder may be diagnosed when these experiences are consistent for an extended period of time.

Personality disorders may last for years or even decades and are very common: they occur in between 10 and 20% of people. They begin in adolescence or early adulthood, are stable over time, and may cause impaired cognition, impulsive actions, and dysfunctional interpersonal relationships.

Diagnosing a personality disorder is not easy and requires a complex set of evaluations. To ensure the right diagnosis and treatment, it is critical that qualified mental health professionals perform these evaluations.


Personality disorders may be caused by a combination of genetics and family history, biological factors such as brain chemicals or hormones, and childhood trauma or distress.

As with so many mental health problems, the exact causes are not yet well-understood. People with a family history, exposure to alcoholism or abuse in childhood are at increased risk. There is often a difficult or unstable upbringing, parental conflict or undue harshness. People with personality disorders may have experienced abandonment in childhood or adolescence, a disrupted family life or poor communication within the family, or abuse.

Signs & Indications

There are several different types of personality disorders and each has different indications, but most people with a personality disorder experience continuous disruption to their daily life, unhappiness and the inability to function in ordinary situations. They may be unable to think clearly or rationally, act impulsively, and have poor or abrupt personal relationships with others.


Cognitive behaviour therapy (CBT) and other similar forms of psychotherapy are sometimes used to treat personality disorders. People under treatment get help in changing how they think, and by considering the way they think and becoming more observant about their own mental state, they can learn to change their behaviour. Psychologists work with individual patients to decide which treatment is the most appropriate.

Here are two common forms of personality disorder. It’s important to know that there are several others and you should not attempt to diagnose yourself or others. If you or someone you know is exhibiting any signs or indications that cause concern, contact us to find a specialist who can help.


Antisocial personality disorder is a condition in which a person is manipulative and deceitful towards others, reckless in behaviour, and disregards the feelings of others. People with APD have a pattern of impulsive, irresponsible and sometimes criminal behaviour.

As with other types of personality disorders, APD is on a spectrum, ranging in severity from occasional to repeated and frequent.

APD is significantly more common in men than in women.

People with APD are significantly more at risk of substance abuse, serious injury or even death through their reckless behaviour. They also struggle to sustain healthy relationships with others.

All humans are sometimes cruel, selfish or ‘badly behaved’ in certain situations. That does not necessarily indicate APD. APD can only be diagnosed after a rigorous psychological assessment.

Signs & Indications

While a proper diagnosis of APD should be done by qualified professionals, here are some signs to be aware of. People with APD may:

  • Be witty, charming, good at flattery and manipulate the emotions and responses of others
  • Disregard their own safety and that of others
  • Lie, steal or get into fights often
  • Not show guilt or remorse even when confronted or in the face of other people’s distress
  • Be angry or arrogant and unable to control their anger
  • Not learn from their mistakes
  • Show repeated disruptive or aggressive behaviour

Some people with APD have a history of conduct disorder during childhood. For example, skipping school; committing acts of vandalism or substance abuse; or being cruel to animals or other children.


APD can be managed and treated, and many people with APD can learn to cope with their condition and resume productive, happy lives. While core characteristics of people with APD (such as a lack of empathy) remain, but the behaviour can be channelled and changed in the right manner.

The difficulty with treatment is more with seeking it: people with APD are characteristically nonchalant about their own problems and thus may not think they need treatment. Friends and family play an important role in making decisions in this regard.

Factors including age, behavioural history, associated problems (for example, substance use), and family circumstances all play a role in determining the right form of treatment.

Cognitive behaviour therapy (CBT) and mentalisation-based therapy are sometimes used to treat APD. People under treatment get help in changing how they think, and by considering the way they think and becoming more observant about their own mental state, they can learn to change their behaviour.


People with borderline personality disorder have long-term patterns of unstable, turbulent emotions that result in impulsive behaviour and chaotic, unpredictable relationships with others.

They are often unperceptive about themselves and have rapidly changing interests and values. Their views can be extreme (all good or all bad) and their opinions of others can change quickly. These intense feelings of like and dislike affect their relationships and behaviours.

BPD is more common in women and may develop in situations of isolation, such as extended hospitalisation for other psychiatric conditions. People with BPD have a fragile sense of self and their relationships with others are impaired as a result. Many struggle with other mental health problems.

BPD is diagnosed using a rigorous psychological evaluation that takes into account the history and severity of behavioural characteristics.

Signs & Indications

Circumstances affect how people behave, and so do other underlying conditions, so not everyone whose opinions and emotions are volatile has BPD. Here are some of the signs to be alert for:

  • Intense fear of being abandoned and hatred of being left alone
  • Displays of inappropriate and disproportionate anger
  • Impulsive behaviour
  • Repeated crises and instances of self-harm


BPD does not impact the person suffering from it; it also affects family and friends. For this reason, family members of a person with BPD may also benefit from psychotherapy.

Talk therapy and sometimes group therapy can be useful in treating BPD. There are several psychotherapy approaches that are effective. Clinicians work with BPD-sufferers on an individual basis to decide which treatment is the most appropriate.