Brief Report: Autism in Individuals with Down Syndrome

As an off-shoot of a study examining the reliability and validity of an adapted version of the Pre-Linguistic Autism Diagnostic Observation Schedule (A-PL-ADOS), 13 individuals with Down syndrome with IQs ranging between 24 and 48 were administered the Autism Diagnostic Interview-Revised (ADI-R) and the A-PL-ADOS, which are well-validated interview and observational diagnostic measures. Three out of 13 met lifetime criteria on the ADI-R, but none of these three showed behavior that met the criterion for autism on the A-PL-ADOS (although two nearly did so). However, two individuals did meet the A-PL-ADOS criterion and showed behavior that fell only just short of meeting lifetime criteria on the ADI-R. Altogether, 5 individuals with Down syndrome may be considered to show an autism spectrum disorder. Of the remaining 8, some showed a few autistic features, and some showed none. The findings raise both methodological and conceptual issues.

Appendix A: Description of participants meeting or nearly meeting algorithm criteria on the ADI-R or the A-PL-ADOS

Participant 1

Participant 1 is an 11-year-old boy with a mental age of 36 months and social functioning at an even lower level. At the age of 4–5 years when functioning at an extremely low mental age, he was markedly limited in his use of facial expressions, did not attempt to share his enjoyment of things with others, had no interest in other children, did not offer comfort to someone if they were sad or hurt, rarely showed social intentionality involving eye gaze and showed very little social response to others. In addition, he had an inconsistent direct gaze, limited social smiling, showed a limited response to the approaches of other children, and had some inappropriateness in his facial expressions. He did not point, demonstrated no imaginative play and was limited in his use of gestures, spontaneous imitation of actions, and social play. His pre-occupation with videos and cars, and his repetitive playing with parts of objects interfered with his participation in other activities.

By the age of 11, however, he had improved significantly in terms of social interaction and communication in that he now smiled socially, pointed, gestured freely, vocalized in a social way, offered to share, showed and directed attention to objects in which he was interested, had a range of facial expression, offered comfort to others, and responded to the approaches of others. Although he responded to familiar people, this was not consistent. He had always indicated his needs by physically pulling someone to what he wanted but he had never used their arm or hand as a tool. Although he still had an intense interest in videos and cars, this had lessened somewhat and he did have a friend with whom he does activities.

During the administration of the A-PL-ADOS he participated fully, demonstrating no indications of autistic behavior, other than a lack of coordination in eye contact and vocalization when a press for joint attention was presented. In summary, the autistic features were evident only in early childhood when he was functioning at a very low mental age.

Participant 2

Participant 2, a 12-year-old boy with a Vineland social quotient of below 20 and a Merrill–Palmer ratio IQ of 35, met criteria for autism on the ADI-R at the age of 4–5 years largely on the basis of a paucity of social/communication skills rather than a particularly “autistic” quality. At this age he showed no imaginative play or interest in other children, nor did he engage in group play. He did not spontaneously imitate the actions of others, point to express interest, nod or shake his head or use other gestures, nor did he seek to share his own enjoyment with others and did not show things to others. His direct gaze used to communicate was limited as was the range of facial expressions he used to communicate, and he sometimes used inappropriate facial expressions. However, he did engage in social smiling, offered comfort, and coordinated eye gaze with vocalization appropriately when he was trying to secure help.

By the age of 12 years he still exhibited many autistic qualities but he had improved in many areas. He has never had any friendships and still did not have any friends. Although he had always had a pre-occupation with flushing toilets, and lined up cars without playing with them constructively, these activities were less intense at 12 than they had been at age 4–5 years. He showed a normal range of facial expressions that were appropriate to the situation, used gestures appropriately, nodded and shook his head albeit with poor head control. He also pointed to express interest, but did so in a limited way. He brought or showed some things to other people, but these were associated with a need for help, or his pre-occupations, rather than simply for the purpose of sharing.

During the administration of the A-PL-ADOS, he rarely vocalized, did not give anything to the examiner, or initiate any joint attention when a “press” was provided. He used some eye contact for social interaction and demonstrated some appropriate pleasure during interactions, but both of these were in a limited way. He used some gestures and showed interest in the examiner’s repetition of his action, but he did not engage in a back-and-forth interaction. He responded to his name being called, but only on the third or fourth press. Enough behaviors of an autistic nature were evident during the administration of the A-PL-ADOS that he did meet criteria on this measure.

In summary, this is a boy with profound mental retardation who met the criteria for autism largely on the basis of a paucity of social/communicative skills rather than because they showed a specifically autistic quality. He showed substantial social impairment, although he was less generally autistic than his algorithm scores would suggest.

Participant 3

Participant 3 is a 29-year-old verbal man with a Vineland social quotient below 20 and a Merrill–Palmer ratio IQ of 48. Although at the age of 4–5 his social–emotional reciprocity was normal or nearly normal (as it is now) with some limitation in social responses, he still demonstrated enough autism features to meet lifetime criteria (on the ADI-R), although his current behavior fell well below the diagnostic threshold. His observed behavior met the A-PL-ADOS algorithm criteria for autism. At the age of 4–5 he showed no imaginative play, did not show or direct attention, did not offer to share, or shake his head to indicate ‘no.’ There was very little social chat at that age and even though he began using phrases at the age of 11, there was still very little or no reciprocal conversation in adulthood. He has never reversed his pronouns, or used idiosyncratic language or stereotyped utterances. He did point to express interest at the age of 4–5 and used some conventional gestures. He showed some interest in other children and some limited group play, but relationships with other people were, and still are, limited to group situations.

As an adult, this participant is now able to nod and shake his head appropriately and will now offer to share in a limited way. He will occasionally show things to other people simply for the purpose of sharing. There is a girl whom he sits beside and to whom he brings presents, but they have no shared activities. This subject has an intense interest in television and enjoys looking at moving objects, although these interests do not restrict his participation in other activities. He needs to fold things in a particular way and becomes anxious if he is prevented from doing it.

During the A-PL-ADOS administration, he used very few gestures, did not smile socially, did not give objects to the examiner, and showed very little in the way of pleasure in the interaction with the examiner. He did not initiate joint attention nor did he repeat his own actions when he was imitated by the examiner, although he did show some awareness of the examiner’s action. On the other hand, he responded readily to his name being called, frequently directed vocalizations to others, and coordinated facial expression, eye contact and words to initiate interaction in a normal manner. Although he did make eye contact and did exhibit a variety of facial expressions, these were somewhat limited in quality and amount.

In summary, this man appeared autistic in many ways, although this was more marked when he was younger. It is notable that, despite other autistic features, his social overtures and responses included many normal features and there have been no abnormal language features at any age.

Participant 4

Participant 4 is a very low functioning, essentially nonverbal, 21-year-old woman (with a Vineland social quotient below 20 and a Merrill–Palmer ratio IQ of 25) whose behavior fell just short of meeting lifetime criteria for autism on the ADI-R in the communication domain. She is very slow in whatever she does, and needs constant prompting to complete any task (such as getting dressed). She is very messy on the toilet. She first used single words at 30 months, but she has never used phrases, does not speak or vocalize socially, and mostly shows no interest in communicating. As a child, she is said to have showed normal eye-to-eye gaze and much social smiling, she did not offer to share objects, did not share her own enjoyment of things with others, or imitate actions. She demonstrated some limited interest in other children, but she did not engage in any sort of group play or imaginative play by herself or with others. Her ability to point for the purpose of expressing interest has always been limited. On the other hand, she did use gestures freely and was able to nod and shake her head at the age of 4–5. As an adult, she smiles less than she did when younger, she has a male ‘friend’ with whom she sits, apparently showing pleasure to be with him, but they have no shared activities. She has always engaged in hand flapping and currently must complete a ritual before passing through a door.

During the administration of the A-PL-ADOS, on which she met criteria, she did not direct any words or vocalizations to the examiner, did not point, give any objects to the examiner, use gestures, or engage in social smiling. She showed no awareness of the imitation of her actions, nor did she demonstrate any joint attention. She did respond readily to her name being called, however, and demonstrated a limited range of facial expressions. Her social overtures and social responses showed many normal qualities, but they were not well coordinated.

This woman meets the criteria for autism primarily on the basis of her major lack of social and communicative skills, rather than on their specifically autistic quality. Her social responsiveness has not increased with age and, in some respects, her social functioning is, if anything, more impaired than in childhood.

Participant 5

Participant 5 is a nonverbal 10-year-old boy, who was untestable in terms of an intellectual assessment and showed profoundly retarded social functioning, who did not quite meet lifetime criteria on the ADI-R but did meet A-PL-ADOS criteria for autism. He became socially withdrawn after developing infantile spasms at 5 months of age. His social responsiveness then gradually improved but remained impaired. Between the ages of 4 and 5 years his social interactions and use of vocalizations were both very limited but he would smile in response to others, showed normal eye gaze, and would hold other children affectionately, but not join in group play.

By the age of 10, he had begun to engage in to and fro social vocalizations, greet familiar people, and showed attachment to particular children but still had no personal friendships that involved shared activities. He still did not nod or shake his head, or point to express interest, and there was little use of gesture and little sharing. He showed a normal range of facial expression at 10 but it had been a little limited when younger. He continued to lack imaginative play. He liked to see things spin, move or roll, and was interested in flags flapping but otherwise he was not particularly repetitive in his play. He liked to mouth objects or touch them with his tongue but did not have any other unusual sensory interests. He occasionally moved his hands in front of his face but has no other mannerisms.

During the administration of the A-PL-ADOS, he showed appropriate social smiling and some pleasure in his interaction with the examiner. Although limited in quality and amount, he did use eye contact for social interaction, and directed some facial expressions and vocalizations toward the examiner. He responded immediately to his name being called. He did not demonstrate any use of joint attention, did not give anything to the examiner, did not use any spontaneous gestures, and although he showed awareness of the examiner’s action when the examiner imitated him, he did not recognize it as an imitation and did not attempt to interact with her.

In summary, this boy’s social functioning seemed to deteriorate after he developed infantile spasms. It then improved somewhat as he became older, but, both as reported and observed, he continued to show a mix of autistic features and some elements of normal social functioning. As with other participants, assessment was made more difficult by his profound intellectual impairment.

Participant 6

Participant 6 is a 31-year-old woman, with a Vineland social quotient below 20 and a Merrill Palmer ratio IQ of 24, who met criteria on the A-PL-ADOS but did not quite meet lifetime ADI-R criteria (although scoring well above the cut-off in the Communication domain). Her first use of single words was at 54 months and very limited use of phrases began at 84 months. There has never been much social vocalization or chat, she shows some use of stereotyped utterances, but her use of language is too limited for any adequate assessment of abnormal language features. She has never used another person’s hand to communicate. There has never been much spontaneous pointing to express interest nor has there been imitation of others. At the age of 4–5, she is said to have responded appropriately to the approaches of others, to have used direct gaze and smiling (which she still does), but there was a limited range of facial expression, little or no imaginative play or imitative social play.

As a child she engaged in group play to a limited extent, showed interest in other children and responded when they approached. Although, as an adult, she shows preferences for particular people, as she did at 4–5 years of age, she does not have any real friends. She is still limited in her use of gestures and her range of facial expressions, does not nod or shake her head, does not point to express interest, or show things that interest her to other people. Other than flicking a toothbrush, she has no other stereotyped repetitive behaviors.

During the administration of the A-PL-ADOS, there was very little vocalization, pointing or use of gestures. Although she did make some social overtures and responses, with some limited eye contact and facial expression, she was impaired in both her social overtures and responses. There was no imaginative or functional play.

In summary, this profoundly retarded woman shows a marked lack of social skills and responsivity and, despite acquiring some limited language, makes very little use of it for communication. Her behavior as reported and as observed was broadly similar, but the presence of some normal social features, together with different ratings on social overtures and responses meant that her behavior fell below the cut-off on the ADI-R but above it on the ADOS. The quality of her social behavior changed little between childhood and adult life.