Schizotypal disorder is a complex condition that is characterized by cognitive-perceptual impairments, oddness, disorganization, and interpersonal difficulties. It often is unrecognized or underdiagnosed. In DSM-5, schizotypal disorder is categorized a personality disorder, but it is also considered part of the schizophrenia spectrum disorders.1 The diagnostic criteria for schizotypal disorder are outlined in the Table.1,2
Although schizotypal disorder has a lifetime prevalence of approximately 4% in the general population of the United States,2 it can present during childhood or adolescence and may be overlooked in the differential diagnosis for psychotic symptoms in pediatric patients.3 Schizotypal disorder of childhood (SDC) can present with significant overlap with several pediatric diagnoses, including schizophrenia spectrum disorders and autism spectrum disorder (ASD), all of which may include psychotic symptoms and difficulties in interpersonal relationships. This overlap, combined with the lack of awareness of schizotypal disorder, can pose a diagnostic challenge. Better recognition of SDC could result in earlier and more effective treatment. In this article, we provide tips for differentiating SDC from childhood-onset schizophrenia and from ASD.
Differentiating SDC from schizophrenia
SDC may be mistaken for childhood-onset schizophrenia due to its perceptual disturbances (which may be interpreted as visual or auditory hallucinations), bizarre fantasies (which may be mistaken for overt delusions), paranoia, and odd behavior. Two ways to distinguish SDC from childhood schizophrenia are by clinical course and by severity of negative psychotic symptoms.
SDC tends to have an overall stable clinical course,4 with patients experiencing periods of time when they exhibit a more normal mental status complemented by fluctuations in symptom severity, which are exacerbated by stressors and followed by a return to baseline.3 SDC psychotic symptoms are predominantly positive, and patients typically do not demonstrate negative features beyond social difficulties. Childhood-onset schizophrenia is typically progressive and disabling, with worsening severity over time, and is much more likely to incorporate prominent negative symptoms.3
Differentiating SDC from ASD
SDC also demonstrates considerable diagnostic overlap with ASD, especially with regards to inappropriate affect; odd thinking, behavior, and speech; and social difficulties. Further complicating the diagnosis, ASD and SDC are comorbid in approximately 40% of ASD cases.3,5 The Melbourne Assessment of Schizotypy in Kids demonstrates validity in diagnosing schizotypal disorder in patients with comorbid ASD.5,6 For clinicians without easy access to advanced testing, 2 ways to distinguish SDC from ASD are the content of the odd behavior and thoughts, and the patient’s reaction to social deficits.
In SDC, odd behavior and thoughts most often revolve around daydreaming and a focus on “elaborate inner fantasies.”3,6 Unlike in ASD, in patients with SDC, behaviors don’t typically involve stereotyped mannerisms, the patient is unlikely to have rigid interests (apart from their fantasies), and there is not a particular focus on detail in the external world.3,6 Notably, imaginary companions are common in SDC; children with ASD are less likely to have an imaginary companion compared with children with SDC or those with no psychiatric diagnosis.6 Patients with SDC have social difficulties (often due to social anxiety stemming from their paranoia) but usually seek out interaction and are bothered by alienation, while patients with ASD may have less interest in social engagement.6