Psychosis is a cluster of symptoms used to define specific psychiatric disorders. Psychotic symptoms include hallucinations, delusions, or disorganization of thoughts and behavior. Children, adolescents, and adults can present with these symptoms in the context of depression, bipolar disorder, schizophrenia, substance use/abuse, delirium, and post-traumatic stress disorder (PTSD).

Few studies have examined hallucination and delusion phenomenology in children, thereby making diagnosis and prevalence difficult to assess. Schizophrenia is estimated to impact 1% of the population, with a peak onset in late adolescence.¹ Early-onset schizophrenia (EOS), before 18 years of age, is rare and is estimated to occur in less than 4% of all cases of schizophrenia, and has a poor prognosis.^2,3 Psychotic symptoms can also be present in other mood disorders in children and adolescents. According to the National Comorbidity Survey Replication-Adolescent Supplement, the lifetime prevalence of mood disorders in adolescents is 14.3%.⁴ It is estimated that 20% of pediatric patients diagnosed with bipolar type I will have symptoms of psychosis during a mood episode.⁵ Regardless of the psychiatric diagnosis, hallucinations and delusions are present within the general population and appear to be associated with worse health function, higher incidence of depression, and higher likelihood of diagnosis and treatment for a psychiatric disorder.⁶

Children with psychosis may present with cognitive abnormalities, emotional difficulties, and changes in social functioning (Table 139-1).³ Studies indicate that premorbid social and emotional function is lower in patients who later on develop schizophrenia or schizoaffective disorder as opposed to mood disorders with psychotic features.⁷ In children and adolescents there is often a prodromal period during which there is a decline in social, emotional, and academic function that predates the onset of psychosis by a period of weeks to months. Changes in social functioning due to new-onset psychosis may present with disruptive behaviors, social withdrawal, or difficulties with peer relationships.

Cognitive manifestations of psychosis include distortions of thoughts to the extent of hallucinations or delusions. Hallucinations are false sensory perceptions in the absence of evidence of stimuli. In children, hallucinations are most frequently auditory in nature.³ David et al. reported the following rates of hallucinations in childhood schizophrenia: auditory (95%), visual (80%), olfactory (30%), and somatosensory/tactile (61%).⁸

Delusions represent distorted or fixed beliefs held by the person that are not substantiated by evidence. Delusions can be impacted by the patient’s interpretation of their environment as well as their cultural and religious beliefs. Systematized delusions (e.g. persecution) are rare in children less than 12 years of age and become more common in the adolescent period.³

Patients presenting with new-onset psychosis can also present with alterations in their mood. Children can present as irritable, angry, or elevated (e.g. mania with psychosis). Negative symptoms may be present such as apathy, flat/blunted affect, and paucity of speech. Mood symptoms may change rapidly for patients and manifest in mood-congruent or -incongruent hallucinations or delusions. For example, a patient with a depressed mood may have mood-congruent hallucinations of voices speaking in a derogatory way about him/her, while having delusions of persecution by peers.

Speech and language may also be impacted by an altered cognitive state. In addition to hallucinations and delusions, patients with psychosis may respond to questions in a disorganized or nonsensical fashion. At times their dialogue may include perseveration on topics, neologisms, or stereotypies (e.g. echolalia, clanging). Behaviors may be congruent with the thought processes and patients may exhibit a regression of behaviors, bizarre behaviors, and other motoric disturbances. Patients may exhibit compulsions that are in response to hallucinations or delusions (e.g. checking behaviors).

Catatonia represents the most extreme presentation of negative symptoms including mutism, immobility, and avolition. Classical catatonia represents severe bradykinesia with unusual properties such as waxy flexibility and stereotypies of the hand or other parts of the body. Conversely, agitated catatonia can present with extreme psychomotor agitation without identified purpose of their actions.

Psychosis can present differently based on a combination of factors including the etiology as well as the developmental stage that the child is in. Early childhood psychosis is a very rare disorder, making it important to rule out any medical or toxic causes of mental status changes with psychosis (Table 139-2). Children should be assessed for seizures, delirium, central nervous system lesions (e.g. tumors), neurodegenerative disorders (e.g. Rett syndrome), infectious diseases (e.g. bacterial or viral meningitis), or ingestion or exposure to toxins (e.g. medications, household chemicals).

Providers should complete a careful medical review of organ systems of the patient to assist in identifying reversible causes of mental status changes. Patients with recent infections, surgeries, or medication changes would be at an increased risk for delirium. Delirium is the diagnosis for anyone who is suffering from a reversible toxic or metabolic derangement that is impacting a person’s mental status. Children suffering from delirium may present with social and emotional regression, withdrawal, mood symptoms (e.g. anxiety, depression), hallucinations, delusions, and sensory misperceptions. Ten percent of children referred to pediatric consultation services for evaluation are eventually diagnosed with delirium due to the significant symptom overlap between psychotic disorders and delirium.⁹ Providers should be cautious when assessing any patient with a sudden onset of mental status changes under these circumstances. The hallmark of delirium is the waxing and waning of consciousness and cognition throughout the day. Psychotic symptoms also wax and wane in delirium, which generally is not the case in schizophrenia or mood disorders.

Carefully identifying and understanding the onset of symptoms is useful in the diagnosis of new-onset psychosis. More acute onset of symptoms suggests a possible physical insult to the body or nervous system. Concurrent physiologic findings (e.g. fever, hypertension) also suggest physical etiologies. An insidious onset may be more consistent with a psychiatric diagnosis. There is a prodromal period associated with schizophrenia that is characterized by a reduction in functioning across social domains. Concurrent or premorbid mood symptoms may help differentiate mood disorder with psychotic features from schizophrenia.

Hallucinations are reported frequently in the pediatric population even in the absence of a psychiatric diagnosis.⁸ Children at different developmental stages can present with hyperactivity, aggression, tearfulness, or regression in response to internal stimulation. There should be a careful assessment of a child’s level of social, emotional, and language function prior to the onset of symptoms prior to any diagnosis. Children with impaired receptive or expressive language or social capacity can present with disruptive and/or bizarre behavior in an effort to express their wishes or desires. These behaviors can easily be misinterpreted as signs of a psychotic disorder. For example, children with autism spectrum disorder with concrete thinking and limited expressive abilities may make statements that seem delusional or psychotic when observed out of context from their baseline level of functioning. Comorbid anxiety disorders can also mask or exacerbate behaviors (e.g. obsessive compulsive disorder) in a way that appear psychotic when reviewed in isolation. For these reasons, a careful assessment should include comorbid Axis I diagnoses, developmental stage, and social/emotional capacity.

At this time, there is no definitive diagnostic test or laboratory analysis for psychosis. The purpose of a complete physical exam and diagnostic tests is to assess for any medical causes of psychotic symptoms and/or exacerbating factors (e.g. depression with superimposed delirium).