Cluster A personality disorders are characterized by odd or eccentric behavior. Individuals in this cluster tend to experience major disruptions in relationships.
Paranoid Personality Disorder
People with paranoid personality disorder are excessively mistrustful and suspicious of others. They assume other people are out to harm or trick them. Such mistrust often extends to people close to them and makes meaningful relationships difficult. These individuals are sensitive to criticism and have an excessive need for autonomy. They often appear tense and are ready to pounce when they think they’ve been slighted by someone. The defining characteristic of people with a paranoid personality disorder is a pervasive unjustified distrust.
Evidence for biological contributions to paranoid personality disorder is limited. Some research suggests the disorder may be slightly more common among the relatives of people who have schizophrenia. In general, there appears to be a strong role in genetics in paranoid personality disorder. Looking too closely at what other people say and do can sometimes lead you to misinterpret them. Certain groups of people such as prisoners, refugees, people with hearing impairments, and the elderly are thought to be particularly prone to paranoid behavior.
Schizoid Personality Disorder
Individuals with schizoid personality disorder seem neither to desire nor to enjoy closeness with others. They do not seem affected by praise or criticism. They consider themselves to be observers rather than participants in the world around them. They share the social isolation, poor rapport, and constricted effect seen in people with a paranoid personality disorder. The social deficiencies of people with this disorder are similar to those of paranoid personality disorders.
Shyness is reported as a precursor to later adult schizoid personality disorder. Abuse and neglect in childhood are also reported among individuals with this disorder. It is rare for a person with the disorder to request treatment except in response to a crisis such as extreme depression or losing a job. It may be that dopamine (which seems to be involved with schizophrenia as well) may contribute to the social aloofness of people with this type of disorder. Therapists often begin treatment by pointing out the value in social relationships. People with this condition may even need to be taught the emotions felt by others to learn empathy. The social skills were never established or have atrophied through lack of use, so we must be cautious in evaluating the effectiveness of treatment.
Schizotypal Personality Disorder
A schizotypal personality disorder is considered by some to be on a continuum of disorders with schizophrenia. It has psychotic-like symptoms but without some of the more debilitating symptoms, such as hallucinations and delusions. Individuals with schizotypal have odd beliefs or engage in “magical thinking” They may believe they are clairvoyant or telepathic, for example. They report unusual perceptual experiences, including such illusions as feeling the presence of another person when they are alone.
A schizotypal personality disorder is viewed by some to be one phenotype of a schizophrenia genotype. Some people are thought to have “schizophrenia genes” (the genotype) yet some will have less severe schizotypy (the phenotype) The idea of a relationship between schizotypal and schizophrenia arises partly from the way people with the disorders behave. Family, twin, and adoption studies have shown an increased prevalence of schizotypy among relatives of people with schizophrenia.