Hallucinations in children are of grave concern to parents and clinicians, but aren’t necessarily a symptom of mental illness. In adults, hallucinations usually are linked to serious psychopathology; however, in children they are not uncommon and may be part of normal development (Box).
A hallucination is a false auditory, visual, gustatory, tactile, or olfactory perception not associated with real external stimuli.1 It must be differentiated from similar phenomenon such as illusions (misperception of actual stimuli), elaborate fantasies, imaginary companions, and eidetic images (visual images stored in memory).
Although hallucinations frequently are considered synonymous with psychotic disorders, in children this rare. Neurobiologic studies (fMRI) of adults show activation of Broca’s area (left inferior frontal gyrus) seconds before patients perceive auditory verbal hallucinations, which suggests that auditory hallucinations may be misidentified self-talk.a,b According to Piaget,c children age <7 may have difficulty distinguishing between events occurring while dreaming and awake. He further theorized that nonpathologic hallucinations could become pathologic when combined with trauma such as abuse. Straussd suggested that psychosis might lie on a continuum with normal phenomenon. In a case series, Wilking and Paulie described how developmental difficulties, deprivation, sociocultural conditions, and family relationships could contribute to impaired reality testing.
Imaginary friends or companions are common among all children. Children who have imaginary friends are more likely to report hearing “voices.”f Imaginary friends:
- appear, function, and disappear at the wish of the child
- pose no threat and often are a source of comfort
- often can be described in detail
- are not ego-dystonic.g
Also, children with imaginary friends will not show evidence of a thought disorder.
a. Shergill SS, Brammer MJ, Amaro E, et al. Temporal course of auditory hallucinations. Br J Psychiatry. 2004;185:516-517.
b. Shergill SS, Brammer JJ, Williams SC, et al. Mapping auditory hallucinations in schizophrenia; using functional magnetic resonance imaging. Arch Gen Psychiatry. 2000;57;1033-1038.
c. Piaget J. The child’s conception of the world. London, United Kingdom: Routledge and Kegan Paul; 1929.
d. Strauss JS. Hallucinations and delusions as points on continua function. Rating scale evidence. Arch Gen Psychiatry. 1969;21:581-586.
e. Wilking VN, Paoli C. The hallucinatory experience: an attempt at a psychodynamic classification and reconsideration of its diagnostic significance. J Am Acad Child Psychiatry. 1966;5:431-440.
f. Pearson D, Burrow A, FitzGerald C, et al. Auditory hallucinations in normal child populations. Pers Individ Dif. 2001;31:401-407.
g. Lewis M. Child and adolescent psychiatry: a comprehensive textbook. 3rd ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2002.
Common, yet a cause for concern
Epidemiologic studies show 2.8% of adults report hallucinations before age 21.2 Nonpsychotic children as young as age 5 have reported hallucinations.3 Hallucinatory phenomenon may be present in 8% to 21% of all 11-year-old children; two-thirds of these patients have no DSM-IV-TR diagnosis.4,5 However, 1 evaluation of 62 nonpsychotic hallucinating children treated in a psychiatric emergency department (ED):
- 34% had depression
- 22% had attention-deficit/hyperactivity disorder (ADHD)
- 21% had disruptive behavior disorders
- 23% had other diagnoses.6
Studies suggest that children who have hallucinations but no other psychotic symptoms have a better long-term prognosis than those with additional psychotic symptoms.7 A 17-year longitudinal study of children with hallucinations and concurrent emotional and conduct problems found:
- up to 50% of patients still experience hallucinations at age 30
- hallucinations did not significantly predict clinical outcome at age 30
- childhood hallucinations did not increase the risk for psychosis, depression, organic brain disorder, or other psychiatric illnesses.7
In a study of children with psychosis and disruptive disorders, at 2- to 8-years follow-up 50% met criteria for major depressive disorder, bipolar disorder, or schizophreniform disorders.8 In a 15-year longitudinal study of 11-year-olds, self-reported psychotic symptoms—such as delusional beliefs and hallucinatory experiences—predicted a high risk of schizophreniform disorder at age 26.9 These studies suggest that experiencing significant disruptions in thoughts and perceptions during childhood may be related to later development of prominent mood and thought disorders.
They can also manifest as comorbid or associated symptoms of disorders not commonly associated with hallucinations, such as ADHD, disruptive disorders, anxiety disorders, and prodromal clinical states. Medications, substance use, and organic and metabolic disorders also must be considered in the differential diagnosis (Table 3).
Hallucinations may occur in low-functioning or anxious children, in the context of psychosocial adversity or abuse, and during bereavement of a deceased parent when the surviving parent is emotionally unavailable.11-13,15-17 Rule out hypnagogic and hypnopompic hallucinations, which are predominantly visual hallucinations that occur immediately before falling asleep and during the transition from sleep to wakefulness, respectively.18 Rarely, a child who has had hallucinations for some time may learn to complain of them when he or she is not hallucinating in order to obtain a primary or secondary gain, such as getting attention from caregivers.