Paranoid personality disorder

Paranoid personality disorder (PPD) is defined in the DSM-5 as a pervasive pattern of distrust and suspiciousness of others whose motives are interpreted as malevolent. Criteria include unfounded suspicion that others are exploiting or deceiving them, preoccupation with unjustified doubts about the loyalty of friends, reluctance to confide due to fear that information will be used against them, interpretation of benign remarks as threatening or demeaning, persistent bearing of grudges, perception of attacks on their character or reputation that are not apparent to others, and recurrent suspicions about a partner's fidelity. It affects approximately 2.3–4.4% of the general population.

From a psychodynamic perspective, paranoid disorder is understood through the mechanism of projection: unacceptable feelings of hostility, envy, or vulnerability are projected onto others, who are then perceived as threatening and malevolent. The paranoid individual does not recognize their own aggressiveness but experiences it as coming from the outside. This defensive operation maintains self-cohesion at the cost of distorting the perception of the interpersonal world. Millon and Davis described the paranoid pattern as a rigid cognitive organization that selectively filters information, confirming expectations of betrayal and discarding evidence of good will.

Differential diagnosis from delusional disorder (persecutory type) is essential: in PPD, suspicions are pervasive but do not reach the intensity or systematization of frank delusions. Unlike paranoid schizophrenia, there are no hallucinations or disorganized thinking. Treatment represents one of the most difficult challenges in psychotherapy, as the disorder's central distrust directly applies to the therapist and the therapeutic relationship. Establishing an alliance requires absolute transparency, respect for the patient's autonomy, and avoidance of any interpretation that might be experienced as intrusive. Cognitive therapy can help examine the evidence behind suspicions, while psychodynamic approaches work to understand the protective function of distrust.