Personality Disorders Explained: Causes, Types, and Treatment

Personality is the way we think, feel and behave. Everyone has habits that can sometimes cause problems.

But when the same patterns continue for years and repeatedly affect relationships, work or daily life, they may be signs of a personality disorder. You may be reading this because the same problems keep appearing in your relationships, work or emotions. Or perhaps someone’s behaviour is repeatedly hurting you.

This guide explains personality disorders, their common types, how they are diagnosed and how treatment can help.

What Is a Personality Disorder?

A personality disorder is a long-lasting pattern in how someone:

• Thinks about themselves and other people
• Manages emotions
• Responds to stressful situations
• Behaves in relationships

These patterns usually appear across different parts of life and are difficult to change without support. An occasional argument, selfish decision or emotional reaction does not mean someone has a personality disorder.

Around 7.8% of people worldwide may have a personality disorder, roughly 1 in 13 [1].

What Are the Types of Personality Disorders?

Personality disorders have traditionally been divided into three groups:

The newer ICD-11 system focuses mainly on how severe the difficulties are and which personality traits are present, rather than placing everyone into one fixed type [2]. However, the older names are still commonly used.

What Do Common Personality-Disorder Labels Mean?

Narcissistic Personality Disorder

Narcissistic personality disorder is more than arrogance or selfishness. It may involve:

• A strong need for praise or admiration
• Difficulty understanding other people’s feelings
• An unstable sense of self-worth
• Strong reactions to criticism

Calling someone a “narcissist” after an argument is not a diagnosis. A person can behave selfishly or hurtfully without having a personality disorder.

Borderline Personality Disorder

Borderline personality disorder may cause intense emotions, fear of being abandoned, an uncertain sense of identity and unstable relationships.

These emotions may change quickly, especially during relationship difficulties. This differs from bipolar disorder, where mood episodes usually last for days or weeks.

Learn more about borderline personality disorder.

Antisocial Personality Disorder

Antisocial personality disorder involves a long-term pattern of ignoring other people’s rights or safety. This pattern usually begins during adolescence.

“Sociopath” and “psychopath” are widely used online and in films, but they are not formal diagnoses. Behaving badly does not automatically mean someone has antisocial personality disorder.

Obsessive-Compulsive Personality Disorder

Obsessive-compulsive personality disorder, or OCPD, involves a strong need for order, control and perfection. The person may believe their standards and behaviour are reasonable.

It is different from obsessive-compulsive disorder (OCD). In OCD, unwanted thoughts cause anxiety and lead to repeated actions or mental rituals that the person usually wants to stop.

Dissociative identity disorder, sometimes incorrectly called “multiple personality disorder”, is also a separate, trauma-related condition. Read about dissociative identity disorder.

The word 'narcissist' has done real damage to understanding. These are long-standing patterns that respond to good therapy; nobody needs to accept a label to start getting better.

Can You Diagnose Someone as a Narcissist?

No. You cannot diagnose another person from their social-media posts, arguments or behaviour in one relationship.

If someone repeatedly hurts, controls or frightens you, you do not need to prove that they have a disorder before setting boundaries or leaving the relationship. Focus on how their behaviour affects you and what you need to feel safe.

Online personality tests cannot provide a reliable diagnosis. A proper assessment usually requires several detailed conversations with a mental health professional.

What Causes Personality Disorders?

There is no single cause. Possible factors include:

• Genetics and temperament
• Childhood neglect or abuse
• Unstable or unpredictable caregiving
• Difficult early relationships
• Trauma and long-term stress
• Learned ways of managing emotions or staying safe

Some patterns may have helped a person cope with difficult circumstances when they were younger but create problems later in life. Understanding the cause does not excuse harmful behaviour, but it can guide treatment.

Learn more about trauma and PTSD.

How Are Personality Disorders Diagnosed?

There is no blood test or scan for a personality disorder. A mental health professional will consider:

• How long the patterns have been present
• Whether they occur in different situations
• Their effect on relationships, work and daily life
• Other possible conditions, such as anxiety, depression or trauma
• Information about the person’s experiences and history

In India, people may first seek help for anxiety, depression or relationship problems. The longer-term personality pattern may only become clear over several appointments. This is normal because diagnosis takes time.

Can Personality Disorders Be Treated?

Yes. Personality disorders can be treated, and many people learn to manage their emotions, build healthier relationships and function better.

Therapy

Therapy is the main treatment. It may help someone:

• Understand repeated patterns
• Manage strong emotions
• Respond differently during conflict
• Develop a more stable sense of self
• Build safer and healthier relationships

Research shows that psychological treatment can reduce symptoms, particularly in borderline personality disorder [3]. The most suitable approach depends on the person and their needs.

Read about what to expect in psychotherapy.

Medication

Medication does not directly change a personality disorder. A doctor may prescribe it for related concerns such as depression, anxiety or sleep problems [4].

Do not begin, stop or change psychiatric medication without medical advice.

When Should You Seek Help?

Consider speaking to a mental health professional if:

• The same painful pattern appears in several relationships
• Strong emotions are difficult to control
• Conflict repeatedly affects work, studies or family life
• You are unsure who you are or what you want
• You recognise a harmful pattern but cannot change it
• Different people have raised similar concerns about your behaviour
• You experience depression, self-harm or suicidal thoughts

You do not need to identify the correct diagnosis before seeking help. You can begin by explaining what keeps happening and how it affects your life.

Can People With Personality Disorders Get Better?

Yes. Change may take time, but treatment can help people understand their patterns, manage emotions and develop healthier relationships.

If these difficulties are affecting your life, you can book a confidential consultation with a qualified mental health professional at Allo Health. If you are concerned about somebody else, read our guide to supporting a loved one.