Autism & psychosis

Psychosis refers to a condition of the mind—or a collection of symptoms that affect the mind—that makes it difficult to determine what is real and what isn’t; it constitutes some loss of contact with reality. In this article, we explore what the research has to say about the overlap between autism and psychosis.

Below, we discuss what the research says about the overlap between autism and psychosis. However, these statistics and data trends don’t necessarily share a relatable narrative of what it’s actually like to experience psychosis as an autistic. To complement this article, Eva has shared her lived experience with psychosis. We recommend checking out her article after you read this one!  

What is psychosis?

Psychosis and psychosis-related conditions (e.g., schizophrenia) are characterized by a set of experiences which constitute some loss of contact with reality. These experiences are typically referred to as positive traits and include hallucinations, delusions, and disorganized speech.

• Hallucinations: This relates to perceiving sensations that are not real. This is most commonly thought of as auditory hallucinations, such as hearing voices.
• Delusions: These refer to beliefs that an individual is unwilling to change in the face of contradictory evidence and that are considered incorrect/false by an outsider. One common example is the belief that someone is out to harm you.
• Disorganized speech: This is characterized by having thoughts that are “all over the place”, jumping from one thought to the next, and incoherent/disruptive speech patterns.

In addition to positive traits, many individuals with psychosis also have negative traits which typically relate to changes in mood. For example, anxiety, low motivation, and blunted emotional experiences.

The relationship between autism & psychosis

Historically, the relationship between autism and psychosis has been confusing. Autism used to be considered a symptom of schizophrenia, a condition associated with psychosis.^[1]Paul Eugen Bleuler and the origin of the term schizophrenia (Ashok et al, 2012) Later, autism and schizophrenia were even considered to be the same condition. It wasn’t until the 1970s that the two were classified as distinct conditions.^[2]The association between autism and schizophrenia spectrum disorders: a review of eight alternate models of co-occurrence (Chisholm et al., 2015)

Even now that they are diagnostically distinct, there appears to be a lot of neurobiological and genetic similarities between these two conditions.^[3]From Kanner to DSM-5: Autism as an Evolving Diagnostic Concept (Volkmar & McPartland, 2014)^[4]Revisiting the Relationship Between Autism and Schizophrenia: Toward an Integrated Neurobiology (de Lacy & King, 2013)^[5]Autism, Psychosis, or Both? Unraveling Complex Patient Presentations (Chandrasekhar et al., 2019)^[6]Autism Spectrum Disorder and Clinical High Risk for Psychosis: A Systematic Review and Meta-analysis (Vasquerizo-Serrano et al., 2022)^[7]The Autism–Psychosis Continuum Conundrum: Exploring the Role of the Endocannabinoid System (Colizzi et al., 2022) For example, when performing brain scans, one study found that in certain brain regions, there was up to 50% overlap in patterns of activity in schizophrenics and autistics!^[8]Evidence of shared and distinct functional and structural brain signatures in schizophrenia and autism spectrum disorder (Du et al., 2021)

Based on diagnostic traits, it is also easy to see similarities between these two conditions. For example, differences in social interactions are common to both autism and schizophrenia.^[9]What is the prevalence of autism spectrum disorder and ASD traits in psychosis? A systematic review (Kindaid et al., 2017)^[10]Recognizing Psychosis in Autism Spectrum Disorder (Ribolsi et al., 2022)^[11]Autism Spectrum Disorder and Clinical High Risk for Psychosis: A Systematic Review and Meta-analysis (Vasquerizo-Serrano et al., 2022) As well, differences in speech patterns, and disorganized thoughts are common to both autism and psychosis.^[12]Formal thought disorder in autism spectrum disorder predicts future symptom severity, but not psychosis prodrome (Eussen et al., 2014)

Moreover, the overlap between psychosis and autism diagnoses is relatively high. Research shows that up to 60% of individuals who experience psychosis display autistic traits and around 35% of autistic individuals experience psychosis.^[13]What is the prevalence of autism spectrum disorder and ASD traits in psychosis? A systematic review (Kindaid et al., 2017)^[14]Prevalence of Asperger syndrome among patients of an early intervention in psychosis team (Davidson et al., 2014)^[15]The association between autism and schizophrenia spectrum disorders: a review of eight alternate models of co-occurrence (Chisholm et al., 2015) Autistics tend to be diagnosed with psychosis-related conditions like schizophrenia and bipolar disorder more than the general population.^[16]Occurrence of psychosis and bipolar disorder in adults with autism: A systematic review and meta-analysis (Varcin et al., 2022)^[17]Bipolar Disorder and Psychosis in Autism (Ghaziuddin & Ghaziuddin, 2021) We also appear to be diagnosed with psychosis at an earlier age compared to neurotypicals. The average age of psychosis onset for neurotypicals is 18.6, but for autistics, it is 16.7.^[18]Clinical Profiles and Conversion Rates Among Young Individuals With Autism Spectrum Disorder Who Present to Clinical High Risk for Psychosis Services (Foss-Feig et al., 2019)

Identifying psychosis in autism

Since there is a high degree of overlap between autistic and psychotic traits, how can we differentiate between autistics who experience psychosis and autistics who don’t?

One study highlights that psychosis in autism can be identified by the presence of positive traits like auditory hallucinations, and delusions. For example, when autistics report perceptual experiences that seem to be “coming from outside of this world”.^[19]Recognizing Psychosis in Autism Spectrum Disorder (Ribolsi et al., 2022) This is different than experiencing sensory sensitivities and sensory overwhelm which relate to heightened perceptual experiences rather than unrealistic perceptual experiences.

The researchers also find that negative traits look different in autistics who experience psychosis versus those who don’t.^[20]Recognizing Psychosis in Autism Spectrum Disorder (Ribolsi et al., 2022) For example, autistics who experience psychosis often experience a general “flattening” of emotional expression. This can be differentiated from the common autistic struggle to display emotions in socially accepted ways in neurotypical contexts (referred to as challenges with “emotional reciprocity”). Emotional flattening occurs across all contexts whereas difficulties with emotional reciprocity tends to be related to social norms.

One major differentiating factor between psychosis and autism is the preference for sameness and repetition. Things like focused interests and routine are very common in autism but are not as common in psychotic conditions like schizophrenia, especially in childhood.^[21]“Autism-plus” spectrum disorders: intersection with psychosis and the schizophrenia spectrum (Cochran et al., 2013)^[22]Psychosis in autism: comparison of the features of both conditions in a dually affected cohort (Larson et al., 2017) Even autistics who experience psychosis seem to have less focused interests and repetitive behaviours than autistics without psychosis.^[23]Psychosis in autism: Comparison of the features of both conditions in a dually affected cohort (Larson et al., 2018) And often, repetitive behaviours in autistics with psychosis are associated with psychosis related triggers rather than special interests or a preference for sameness.^[24]Recognizing Psychosis in Autism Spectrum Disorder (Ribolsi et al., 2022)

Risk factors for psychosis in autistics

Research has identified several factors that put autistics at an increased risk of developing psychosis. We have compiled the most common risk factors into 3 categories: stress, trauma, and co-occurring conditions.

Stress

Stress has been linked to psychosis.^[25]The Fragile Brain: Stress Vulnerability, Negative Affect and GABAergic Neurocircuits in Psychosis (Taylor et al., 2019) It is believed that when an individual’s stress exceeds their capacity for coping, this can increase the risk of psychosis. Since autistics typically experience a lot of stress living in a neurotypical world, it makes sense that we may be “pushed into” psychosis. My interpretation of the relationship between stress and autism is that as a result of being overwhelmed, we may experience psychosis in a similar way that we experience meltdowns or shutdowns.

Trauma 

Interpersonal trauma and PTSD have been strongly linked to psychosis in autistics.^[26]Interpersonal Trauma and Posttraumatic Stress in Autistic Adults (Reuben, Stanzione, and Singleton, 2021) In autistics who have experienced psychosis, 50% report a history of experiencing trauma and 44% met the official diagnostic criteria for PTSD. These rates of trauma were particularly high for cisgender women (78%), nonbinary individuals (76%), and trans men (90%). Interpersonal trauma specifically increases vulnerability to psychosis-related dissociative experiences (e.g., feeling disconnected from reality, from yourself, from your emotions, etc.).

Childhood trauma has also been linked to the development of psychosis in autistics. One recent study found that bullying in childhood explains the relationship between autistic traits (e.g., social communication differences) and the development of psychosis in early adulthood.^[27]Childhood Trauma As a Mediator of the Association Between Autistic Traits and Psychotic Experiences: Evidence From the Avon Longitudinal Study of Parents and Children Cohort (Dardani et al., 2023) Others studies show that any form of trauma experienced during childhood, like sexual and physical abuse, also increased the risk of autistics developing psychosis.^[28]Childhood Adversities Increase the Risk of Psychosis: A Meta-analysis of Patient-Control, Prospective- and Cross-sectional Cohort Studies (Varese et al., 2012)^[29]Risk of psychosis in autism spectrum disorder individuals exposed to psychosocial stressors: A 9-year chart review study (Bortoletto et al., 2023) Therefore, it seems that exposure to childhood trauma—regardless of type—increases the risk of developing psychosis. 

Co-occurring conditions

Depression is a common experience for autistics with psychosis. 64% of autistics with psychosis also report experiencing depression.^[30]Psychosis in autism: Comparison of the features of both conditions in a dually affected cohort (Larson et al., 2018) One theory is that because many of the characteristics of depression already overlap with the characteristics of psychosis-related conditions (like a loss of pleasure), and autistics are at an increased risk of experiencing depression overall, our depression earlier in life may eventually lead to psychosis.^[31]Psychosis in autism: Comparison of the features of both conditions in a dually affected cohort (Larson et al., 2018)

Anxiety is also commonly associated with psychosis. For example, up to 50% of individuals with schizophrenia also have anxiety.^[32]How Prevalent Are Anxiety Disorders in Schizophrenia? A Meta-Analysis and Critical Review on a Significant Association (Achim et al., 2011) However, this anxiety may arise as a result of psychosis (instead of psychosis arising as a result of anxiety). For instance, paranoia or a loss of contact with reality may be what is causing co-occurring anxiety.

ADHD is another condition that puts autistics at an increased risk of developing psychosis. One recent study found that AuDHD (autism + ADHD) was associated with more psychosis traits than autism alone.^[33]Comorbidity of autism spectrum and attention deficit/hyperactivity disorder symptoms and their associations with 1-year mental health outcomes in adolescents and young adults (Suen et al., 2024)

Are similarities in traits indicative of increased risk?

We discussed earlier that many autistic traits and psychotic traits overlap. Interestingly, research does not always support a link between shared traits in childhood and the development of psychosis in adolescence.

For example, even though it is common for both autistics and psychotics to experience disrupted and disorganized thought processes and speech patterns, these characteristics in autistic children are not associated with an increased risk of the development of psychosis later on in life.^[34]Formal thought disorder in autism spectrum disorder predicts future symptom severity, but not psychosis prodrome (Eussen et al., 2014)

While psychosis is pretty common in autism, in a second post, Autism & psychosis: misattributions, we will explain how psychosis is often misattributed to autistic traits.

But have you experienced genuine psychosis? We would be interested in reading about your experience of it.

Summary

• Psychosis is a common occurrence in autism.
• There are many genetic and neurobiological similarities between autism and psychosis.
• Risk factors include experiences of trauma, high levels of stress, and co-occurring conditions like anxiety, PTSD, depression, and ADHD.

If you would like to learn about what it’s like to experience psychosis as an autistic, check out Eva’s experience of psychosis.