Case Lab · Type B · Boundary

F21

A diffuse odd pattern, or one fixed belief?

Deniz, 41, has for as long as coworkers can remember been described as 'a bit odd' — wearing mismatched clothing, speaking in a roundabout way, and keeping to himself. Over the past four years, however, one specific belief has taken hold and hardened: he is completely convinced that a former business partner has been tampering with his mail and bank records to ruin him financially, and he can describe this in detailed, organised terms whenever it comes up. Outside this one topic, his speech is ordinary, his affect is unremarkable, and he functions well at work and manages his own finances (aside from repeatedly changing banks 'to stay ahead of' the alleged tampering). He has never had hallucinations or a period of thought disorder.