Paranoid personality disorder (PPD) is a mental condition in which a person has a long-term pattern of distrust and suspicion of others. The person does not have a full-blown psychotic disorder, such as schizophrenia.
Causes of PPD are unknown. PPD seems to be more common in families with psychotic disorders, such as schizophrenia and delusional disorder. This suggests genes may be involved. Other factors may play a role as well.
PPD seems to be more common in men.