Forty years ago, autism was regularly referred to as childhood schizophrenia and the links between the two conditions have continued to this day. Recent studies have shown that the features of autism spectrum disorders sometimes precede the onset of childhood-onset schizophrenia.
This cohort study published by researchers from Cardiff University looks at the relationship between early autistic traits that occur in young children and psychotic experiences that occur later in adolescents. It shows that speech problems, odd rituals or unusual habits in young children are associated with an increased risk of psychosis in adolescence.
The study involved 6,439 children from the South West of England who were all part of the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. The mothers of all these children answered questions about their kids’ behaviour before the age of 3 and later when they were aged 7-8. The questions covered:
- Speech development
- Social interaction
- Odd rituals or unusual habits that were hard to interrupt
- Whether or not these traits had cleared up completely by the age of 7 or 8
At the age of 12, the children were interviewed by psychologists (who were blind to their childhood autistic traits) and assessed for psychosis-like symptoms such as hallucinations, delusions and thought interference. Experiences that may have been caused by sleep, substance use or fever were excluded. Known confounders were also excluded.
Here’s what they found:
- Over 11% of the children in the study (744) reported suspected or definite psychotic experiences
- Children whose mothers had concerns about their speech at age 3 were more likely to have suspected or definite psychotic experiences at age 12 (OR 1.58, 95% CI 1.19 to 2.10)
- Children whose mothers reported continued concerns over speech development at age 7–8 were more likely to have suspected or definite psychotic experiences at age 12 (OR 2.11, 95% CI 1.35 to 3.30)
- There was no significant association between maternal concern about unusual rituals at age 3 and psychotic experiences at age 12 (OR 1.74, 95% CI 0.94 to 3.23)
- But there was a significant association between maternal concern over unusual rituals at age 7–8 and psychotic experiences at age 12 (OR 3.05, 95% CI 1.49 to 6.22)
- Maternal concerns about early or persistent social interaction problems were not associated with psychotic experiences at age 12 (problems by age 3: OR 1.11, 95% CI 0.76 to 1.63; problems persisting at age 7 to 8: OR 1.41, 95% CI 0.82 to 2.45)
The researchers concluded:
Childhood autistic traits, and particularly speech problems and odd rituals or unusual habits, are associated with psychotic experiences in adolescence. This may be a result of a shared aetiology or because autistic traits may also be an early precursor of psychotic experiences.
This study tells us that clinicians who work with young people with autism should consider the possibility of psychosis.
Bevan Jones R, Thapar A, Lewis G, Zammit S. The association between early autistic traits and psychotic experiences in adolescence. Schizophr Res. 2012 Mar;135(1-3):164-9. Epub 2012 Jan 13. [PubMed abstract]