Persecutory ideas are a major clinical problem and are associated with impaired functioning, reduced compliance with medication and increased risk of hospitalization. Persecutory ideation is defined as the false conviction that others are threatening or conspiring against one. Although persecutory delusions are mainly described and experienced in schizophrenia spectrum disorders, they also occur in other neurological and psychiatric diagnoses including Alzheimer disease, epilepsy, depression, mania, dementia and post-traumatic stress disorder. Moreover, epidemiological data from general and clinical populations indicated that paranoid beliefs occur on a hierarchy of severity and are present to a lesser degree in the general population, with paranoid delusions representing the severe end of a continuum. In this review we focus on the important advances following a decade of research from psychological sciences, and more particularly the work of Daniel Freeman and Philippa Garety in England. Their work has demonstrated that a range of causal factors are involved in the development and maintenance of delusions beyond the traditional cognitive and behavioural models. Indeed, there is now well-validated evidence that sleep disturbances, worry proneness, reasoning biases, such as failure to consider alternative explanations or belief confirmation bias, abnormal experiences such as hallucinations, negative self-beliefs, and safety behaviours, are central factors that contribute to the paranoid phenomenon. In this review, we describe each of these causal factors in detail as well as the clinical interventions developed by Freeman and his collaborators, including the integrative and modular "Feeling Safe" intervention. Broadly speaking, the aim of this psychological intervention is for patients to relearn safety by exposing them to situations they consider as potentially dangerous after reduction of the influence of the maintenance factors described above. A recent publication showed that the Feeling Safe program led to recovery in persecutory delusions for 50% of patients having poor response to antipsychotic medication, making the intervention as the most effective psychological treatment for persecutory delusions. Finally, we will critically discuss the efficacy data from the numerous clinical studies validating its effectiveness. Prospects for the implementation of the Feeling Safe program in France also is discussed., (Copyright © 2023 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.)