RecruitingBehavioural interventionVolatility in Paranoia (VIP) Trial: An RCT of Changes in Volatility With PsychotherapyThe goal of this clinical trial is to learn whether learning and belief updating change in response to the treatment of persecutory delusions, in individuals with schizophrenia-spectrum disorders. The main questions are: 1. do prior expectations about environmental volatility reduce following effective psychotherapeutic treatment of delusions? 2. does corresponding brain activity related to volatility change with effective treatment of delusions? Participants will: 1. engage in CBTp or TAU + phone check-ins for 16 weeks 2. complete assessments at 4 timepoints over the course of 6 months 3. complete an MRI when possible