Hallucinations occurring during childhood have been reported in both clinical and nonclinical populations. Arguably the most intriguing type of hallucination reported in 13-22% of healthy children around 4 years of age, and in about 45% of children between 5 and 12 years of age, is the * imaginary companion. Imaginary companions tend to take the form of * compound hallucinations. They are described by the children who experience them as other creatures: children, fairy tale characters, television characters, and toy animals, all with definite perceptual characteristics. In a population-based cross-sectional study of hallucinations experienced by older children and adolescents (i.e. in the age group of 11 through 21 years) 9% reported having had one or more isolated * auditory hallucinations, 6% isolated *visual hallucinations, and 7% compound (i.e.auditory plus visual) hallucinations. Much higher prevalence rates of hallucinations are found in clinical populations of children and adolescents. Some examples of clinical disorders associated with a markedly raised prevalence rate of hallucinations are thyroid disease, parathyroid disease, porphyria, Wilson's disease, encephalitis, * meningitis, leprosy, migraine, epilepsy, Tourette's syndrome, and velo-cardio-facial syndrome. Moreover, a substantially higher prevalence rate of hallucinations is seen in children and adolescents with a clinical diagnosis of * schizophrenia, mood disorders, or anxiety disorders. The predictive value of hallucinations occurring in childhood or adolescence is a complex issue, but overall, empirical studies would seem to suggest that most of these hallucinations are transient in nature, and that only a minority of cases tend to develop into a major *psychotic disorder. However, an increased likelihood ratio was found for the development of depressive disorder, *post-traumatic stress disorder, substance use disorder, and social phobia later in life.
References
Aleman, A., Laroi, F. (2008). Hallucinations. The science of idiosyncratic perception.New York, NY: American Psychological Association.
Pearson, D., Rouse, H., Doswell, S., Ainsworth, C., Dawson, O., Simms, K., Edwards, L., Faulconbridge, J. (2001). The prevalence of imaginary companions in a normal child population. Child: Care, Health and Development, 27, 13-22.
Pilowsky, D., Chambers, W., eds. (1986). Hallucinations in children. Washington, DC: American Psychiatric Press.
Yoshizumi, T., Murase, S., Honjo, S., Kameko, H., Murakami, T. (2004). Hallucinatory experiences in a community sample of Japanese children. Journal of the American Academy of Child and Adolescence Psychiatry, 43, 1030-1036.