Introduction: High-functioning autism (HFA) and Aspergers syndrome (AS) are autism spectrum disorders (ASD) characterised by disturbances in social interaction, both verbal and non-verbal communication and repetitive and/or restrictive behaviour since early childhood. Symptoms appear generally during early childhood and adolescence. The increasing need to clarify diagnostic queries in advanced age led to the constitution of specialised outpatient clinics for adults involving a growing amount of HFA/AS subjects diagnosed late in life. However, thus far neuropsychological data about this group are scarce.
Methods: We present a subgroup of 39 patients with HFA/AS (mean age at diagnosis 31.1 ± 8.9 years) who were consecutively diagnosed at the autism outpatient clinic at the Department of Psychiatry at the University Hospital Cologne. Autistic symptoms (autism spectrum quotient; AQ), depressive symptoms (Beck depression inventory; BDI), general intelligence (HAWIE-R), social cognition ("theory of mind", ToM) and executive functioning (COWAT) were systematically studied in comparison to a control group matched for age, education, gender and intelligence (n = 39).
Results: HFA/AS subjects presented higher AQ scores (40.4 ± 5.2) as opposed to the healthy controls (13.5 ± 4.8). Neuropsychologically, patients showed deficits in social cognition, executive functions and in subtests of HAWIE-R related to verbal comprehension and perceptual organisation as opposed to the healthy control group.
Discussion: The diagnosis of autistic disorders in adulthood basically relies on the clinical assessment of autistic core symptoms which were corroborated by high AQ values. The self-rating instrument AQ was found to be highly discriminative between the HFA/AS group and the healthy control group. The neuropsychological profile of adult HFA/AS patients diagnosed late in life is compatible with that of previously investigated HFA/AS populations. These findings show that such basic autism-associated deficits persist until adulthood, although patients are able to learn social rules.