Ethnic minority status and childhood trauma are established risk factors for psychotic disorders. Both are found to be associated with increased level of positive symptoms, in particular auditory hallucinations. Our main aim was to investigate the experience and effect of childhood trauma in patients with psychosis from ethnic minorities, hypothesizing that they would report more childhood trauma than the majority and that this would be associated with more current and lifetime hallucinations.
In this cross-sectional study we included 454 patients with a SCID-I DSM-IV diagnosis of non-affective or affective psychotic disorder. Current hallucinations were measured with the Positive and Negative Syndrome Scale (P3; Hallucinatory Behaviour). Lifetime hallucinations were assessed with the SCID-I items: auditory hallucinations, voices commenting and two or more voices conversing. Childhood trauma was assessed with the Childhood Trauma Questionnaire, self-report version.
Patients from ethnic minority groups (n = 69) reported significantly more childhood trauma, specifically physical abuse/neglect, and sexual abuse. They had significantly more current hallucinatory behaviour and lifetime symptoms of hearing two or more voices conversing. Regression analyses revealed that the presence of childhood trauma mediated the association between ethnic minorities and hallucinations.
More childhood trauma in ethnic minorities with psychosis may partially explain findings of more positive symptoms, especially hallucinations, in this group. The association between childhood trauma and these first-rank symptoms may in part explain this group's higher risk of being diagnosed with a schizophrenia-spectrum diagnosis. The findings show the importance of childhood trauma in symptom development in psychosis.
Hallucinations are a common feature of certain degenerative diseases with a risk of dementia such as Alzheimer's disease, Lewy body dementia, and Parkinson's disease. Obtaining valid epidemiological data is nevertheless quite difficult because of methodological problems. As a rule, hallucinations are more prevalent in Lewy body disease than Parkinson's disease or Alzheimer's disease. The prevalence in parkinsonian dementia is about the same as in Lewy body disease. Complex visual hallucinations predominate, auditory or tactile hallucinations are more exceptional. Minor forms (illusions, sensation of presence) are also observed. Recurrence is common, mainly in the evening or at night. Patients with advanced mental impairment generally take the hallucinations for reality. The hallucinations can be associated with psychological and behavioral disorders such as delusionnal idea or identification disorders. It is important to search for other causes of hallucinations such as drugs, ocular disorders, or depression, but many of these disorders are common comorbidities in elderly patients with degenerative disease. There is no unique model fitting all the hypothesized pathogenic mechanisms. Complex visual hallucinations most likely arise from abnormal activation of the extra-striat temporal associative regions, but only hypothetical mechanisms have been proposed. Genetic studies and functional imaging have not provided convincing evidence. Current focus is placed on an imbalance between deficient cholinergic transmission and preserved or augmented monoaminergic transmission at the cortical level, but other neurotransmission systems could be involved. The dream dysregulation mechanism proposed in Parkinson's disease cannot be generalized. The link between cognitive disorders and hallucination is also poorly understood: hallucinations are associated with more severe cognitive impairments or more rapid cognitive deline in Parkinson's disease and Alzheimer's disease, but the association with specific cognitive disorders remains to be fully explored.