The Diagnostic and Statistical Manual of Mental Disorders fourth edition, DSM IV-TR, a widely used manual for diagnosing mental disorders, defines paranoid personality disorder (in Axis II Cluster A) as:
A) A pervasive distrust and suspicion of others such that their motives are interpreted as malevolent, beginning by early adulthood and present in a variety of contexts, as indicated by four (or more) of the following:
- suspects, without sufficient basis, that others are exploiting, harming, or deceiving him or her
- is preoccupied with unjustified doubts about the loyalty or trustworthiness of friends or associates
- is reluctant to confide in others because of unwarranted fear that the information will be used maliciously against him or her
- reads benign remarks or events as threatening or demeaning.
- persistently bears grudges, i.e., is unforgiving of insults, injuries, or slights
- perceives attacks on his or her character or reputation that are not apparent to others and is quick to react angrily or to counterattack
- has recurrent suspicions, without justification, regarding fidelity of spouse or sexual partner.