Do the traits of autism-spectrum overlap with those of schizophrenia or obsessive-compulsive disorder in the general population?

Social and communicative deficits, restricted interests and repetitive behaviors are diagnostic features of autism spectrum disorders (ASD). The present study examined the relationship between autistic characteristics and schizophrenia-spectrum traits as well as between autistic characteristics and obsessive-compulsive traits in typically developed young adults. The Autism-Spectrum Quotient (AQ) was given separately to two large samples. In addition, one sample (N = 662) was given the Schizotypal Personality Questionnaire (SPQ) to assess schizophrenia-spectrum traits, whereas the other sample (N = 347) was given the Padua Inventory (PI) to assess obsessive-compulsive disorder (OCD) traits. The results revealed a moderate correlation between the AQ and the SPQ total scores; however, multiple regression analyses showed that the “Cognitive-Perceptual” factor did not predict the autism-spectrum degree, although autistic characteristics and schizophrenia-spectrum traits had common social–emotional difficulties. Similarly, there was a moderate correlation between the AQ and PI total scores, which suggests that they had common problems in cognitive aspects; however, autism-spectrum and OCD traits differed with regard to other behavioral characteristics including repetitive or impulsive behaviors. Therefore, there was not a large overlap of the autism-spectrum and either the schizophrenia- or obsessive-compulsive spectrums, although certain traits were correlated with each other.

► We examined the relationship between the autism-spectrum and schizophrenic traits.
► We also examined the relationship between the autism-spectrum and obsessive-compulsive traits.
► The autism-spectrum partly resembles the schizophrenia-spectrum and the obsessive-compulsive spectrum.
► However, there was not a large overlap of the autism-spectrum and either the schizophrenia- or obsessive-compulsive spectrums.
► The proportion of people with ASD who show some SPD or OCD traits at a diagnostic level is very small.