Personality disorders are classified into three clusters: cluster A, cluster B, and cluster C based on the similarities between disorders.

Cluster A

Cluster A disorders have symptoms that others see as bizarre. Sometimes, even strangers can notice these symptoms in people with Cluster A disorders. The disorders in this cluster are:

Paranoid

This disorder causes people to feel constantly suspicious of others for no apparent reason. They believe that the people around them are somehow working against them. Due to this paranoia, they may resist forming meaningful relationships, opening up to others, or forgiving perceived slights.

Schizoid

People with this disorder feel little to no desire to have relationships with others, including sexual relationships, friendships, or close relationships with family. These patients find it difficult to note social cues, express emotions, or find joy in activities that include socialising.

Schizotypal

People often notice that those with this disorder have strange ways of talking, acting, and emoting. They may hear voices, believe that everyday things leave hidden messages for them, and believe that their thoughts are magical. People with schizotypal personality disorder have trouble forming relationships as they are always suspicious of others.

Cluster B

Those who fall under this cluster of personality disorders are perceived to be dramatic, erratic, and unpredictable by others.  The disorders in this cluster are:

Histrionic

This condition causes patients to have dramatic, unpredictable outbursts. However, the distinctive feature of histrionic personality disorder is that people have these episodes as a way to seek attention. People with this disorder may also feel like their relationships are intense, even when the other person believes the relationship is shallow. Their emotions shift rapidly and dramatically, and the people around them greatly influence their behaviors.

Narcissistic

This disorder makes people believe that they are more important than others. As such, they may think less of or even fail to notice the needs of others. People with narcissistic personality disorder expect constant praise from those around them and may exaggerate their credentials. They may fantasize about holding more power and envy those with higher statuses. People describe them as arrogant.

Borderline

People with borderline personality disorder are gripped by an overwhelming fear of being abandoned or left alone. This often leads to signs like impulse behaviors, including gambling, unsafe sex, and binge eating. They often have fragile self-worth and unstable relationships. When interpersonal conflict is high, people with borderline personality disorder have paranoia and outbursts of anger.

Anti-social

Media portrayals and casual conversations often use the term “sociopath,” to describe people with this condition. One of the hallmark symptoms of antisocial personality disorder is the inability to care about other people’s needs and feelings. This leads people with this disorder to violate people’s rights, steal, cheat, and con others. They often have trouble with the law and can act violently. People with this disorder feel little to no remorse for their actions because they cannot understand how they hurt someone else.

Cluster C

Cluster C personality disorders cause interpersonal friction due to the person’s inability to face certain fears. The conditions in this cluster are:

Dependent

They rely on others to make decisions for them and take care of all their needs. They are afraid to take care of themselves. As such, people with this disorder are at risk for being abused and staying in those situations, even when they have options for leaving.

Avoidant

People with this disorder are afraid of any criticism or rejection. In order to avoid these experiences, they may go through extreme measures to avoid contacting people at work or attending social events.

OCPD

People with this disorder fear that if they do not carry out certain tasks or stick to rigid rules, something horrific will happen. As such, they obsess over orderliness, rules, and cleanliness. This inflexibility can hurt their relationships.