Anxiety and Preoccupation in Cases of Autism Spectrum Disorder (ASD) Diagnosed after Age 16

Background:  Some ASD cases show few obvious characteristics during early childhood and first diagnosis as an adult is not uncommon. Delay in the provision of support may then become a problem.

Objectives:  Investigation of the developmental characteristics of such cases may help to identify early support needs.

Methods:  The subjects were 41 high-functioning ASD individuals aged at least 16 years and IQ 70 or higher (measured within the previous 3 years) assigned to a Delay Group (19 individuals, average IQ=102.8, average age 30.0 years, male/female ratio = 15:4), where a definite diagnosis of ASD was made after the age of 16, or an Early Group (22 individuals, average IQ=100.4, average age 25.4 years, male/female ratio = 18:4), where this diagnosis, or an observation of maladjustment, was made before age 16. Development was investigated using 1) a developmental history, 2) evaluation of the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS) peak symptoms during infancy and evaluation of current symptoms on the adolescents/adults scale, 3) the Autism-Spectrum Quotient (AQ) Japanese version, 4) Early childhood anxiety scale, 5) Preoccupation scale. 1) was recalled by the parents, 2) was assessed by a psychologist or doctor, 3) was the subject’s description, 4) the parents’ retrospective assessment of the subject at 3 to 5 years of age, and 5) was the subject's retrospective assessment of his/her condition at Junior High School. 4) rates social anxiety, general anxiety, separation anxiety and specific phobia and 5) describes self-preoccupation and external preoccupation.

Results: Average age at definite diagnosis was 24.7 years in the Delay Group and 14.4 in the Early Group, significantly different. There was no significant inter-group difference in difficulty in child-raising before school age. The PARS peak symptom scale for preschoolers was significantly different (Delay Group 14.1, Early Group 30.0) as was the adolescents/adults scale (Delay Group 19.4, Early Group 25.8). The four social items in preschoolers PARS were marked in both groups, with no inter-group difference. These items may provide a means of earlier diagnosis of the Delay Group. The only significant intergroup difference for the early childhood anxiety scale was for social anxiety (Delay Group 31.7, Early Group 36.8). However the social anxiety score of the Delay Group was higher than the average for preschoolers overall (Nishizawa, 2011). The only significantly different preoccupation was external preoccupation (Delay Group 33.3, Early Group 29.9). All ASD group members showed higher values than average university students for self-preoccupation (37.5) and external preoccupation (27.5) (Sakamoto; 1998).

Conclusions: The ASD characteristics of the Delay Group were less noticeable than those of the Early Group. However, (1) social interaction during infancy was somewhat problematical, (2) social anxiety during early childhood was greater than average children, and (3) external preoccupation during Junior High School years were also marked. These may be early signs for the Delay Group.