Paranoid personality disorder — workplace grievance and risk (MEQ)

(i) Working diagnosis. Paranoid personality disorder (DSM-5-TR) with hazardous alcohol use and occupational crisis. Operational requirements: general PD criteria (enduring, inflexible, pervasive pattern with impairment); pervasive distrust/suspiciousness with ≥4 of 7 features (here: plots/exploitation suspicions, reluctance to confide, hidden meanings in emails, grudges, fidelity suspicions — and likely further features on full history); beginning by early adulthood (15+ year pattern); not exclusively during schizophrenia, bipolar/depressive psychosis, or another psychotic disorder (no hallucinations or thought disorder described). Confirm longitudinal collateral and substance timeline.[2][3]

(ii) Discriminators. Delusional disorder: fixed false beliefs of delusional intensity, often encapsulated, that are incorrigible; behaviour organised around the delusion. This stem describes long-standing overvalued suspiciousness and grudges without stated fixed incorrigible delusion — still reassess intensity and fixity carefully over time, especially if beliefs crystallise.[3][7] Schizotypal PD: cognitive-perceptual oddness, magical thinking, eccentric behaviour/speech, unusual perceptions — not described here; PPD core is pure pervasive distrust without marked oddness.[2]

(iii) Mechanisms. Cognitive threat bias and hostile attribution maintain confirmation-seeking loops; developmental trauma/betrayal and social stress are central in modern clinical reviews, reframing many cases beyond a pure mild-schizophrenia narrative; psychodynamic projection and fragile self-esteem may complement formulation. Dimensional models of trait-paranoia fit the chronic graded pattern.[1][2]

(iv) Immediate priorities. Clarify imminence of harm, means, and identifiable targets of "make them pay"; staff/workplace safety; UDS/medical exclusion of acute substance-driven paranoia; transparent explanation of role and confidentiality limits if risk escalates; avoid early deep confrontation; engage occupational health with careful information-sharing principles. Alcohol pattern needs assessment now because it amplifies impulsivity and conflict.[1][3]

(v) Medium-term plan. Alliance-first psychotherapy: transparency, predictability, paced collaborative empiricism, rupture repair; CBT adaptations for threat bias; CAT has published SCED signals in PPD; schema-informed work draws on mixed-PD RCT principles. Cluster A treatment syntheses suggest psychosocial interventions can be feasible but evidence remains limited/heterogeneous.[4][5] Treat alcohol misuse with standard psychosocial pathways. No disease-modifying drug for PPD; pharmacotherapy only for targets.[3][6] If major depression is confirmed: sertraline 50 mg orally daily, early review, titrate 50–150 mg as tolerated with limited dispensing if overdose risk — treats depression, not PPD. Avoid chronic benzodiazepines for trait mistrust. Multi-agency risk review if threats escalate; document formulation and review dates.[3][6]