The Bergen-Montpellier grandiose ideas questionnaire – B-MGI: a new tool for measuring grandiose delusions

Hooked on a memory: How rumination about past positive events might contribute to grandiose ideas?

OBJECTIVES

Dwelling about positive experiences has been found to be positively related to mania and grandiose ideas. Nevertheless, besides some important limitations, past research has also neglected the nature (or characteristics) of memories individuals dwell on, and that might be specifically associated with grandiose ideas. Thus, the present study aimed to replicate previous studies while considering the role of specificity and the importance of memory used to increase grandiose feelings.

METHOD

In total, 219 participants were included and, after completing the memory induction, were randomized to either the rumination condition or the distraction condition. They also completed different questionnaires assessing positive rumination and grandiose ideas.

RESULTS

Overall, rumination, compared to the distraction condition, led to the maintenance of grandiose ideas and positive affect from T2 to T3. Regression analysis showed that the specificity of memory was associated with grandiose ideas at T2, which predicted grandiose ideas at T3.

CONCLUSIONS

Our results confirm rumination's causal role in forming grandiose ideas. We also found that autobiographical memory and, more specifically, the capacity to recall past positive experiences coupled with repeatedly thinking about them might constitute a fundamental pathway leading to the persistence of such beliefs. The use of a non-clinical sample limits the results and needs replication in clinical samples.

Mapping psychotic-like experiences: Results from an online survey

Suggestions have been made that psychotic-like experiences (PLEs), such as hallucinatory and delusional experiences, exist on a continuum from healthy individuals to patients with a diagnosis of schizophrenia. We used the screening questions of the Questionnaire for Psychotic Experiences (QPE), an interview that captures the presence and phenomenology of various psychotic experiences separately, to assess PLEs in Norway. Based on data from an online survey in a sample of more than 1,400 participants, we demonstrated that the QPE screening questions show satisfactory psychometric properties. Participants with mental disorders reported more frequent lifetime and current hallucinatory experiences than participants without mental disorders. Childhood experiences were rather low and ranged from 0.7% to 5.2%. We further replicated findings that young age, illegal drug use, lower level of education, and having parents with a mental disorder are associated with higher endorsement rates of PLEs. Finally, a binomial regression revealed that the mere presence of PLEs does not discriminate between individuals with and without a mental disorder. Taken together, the findings of the present study support existing models that both hallucinations and delusions exist on a structural and phenomenological continuum. Moreover, we demonstrated that the QPE screening questions can be used by themselves as a complementary tool to the full QPE interview.