First signs in infants and toddlers

In the first year of life

According to the guideline, the majority of studies suggest that affected children differ little in their behaviour from others in the first year of life, and that striking differences in social communication become visible mainly in the second year. ^{[1, Ch. B.2.5.1]} Individual, non-repeated differences have been described, such as less babbling with syllable repetition at 9 to 12 months or setbacks in communication. ^{[1, Ch. B.2.5.1]} The guideline recommended: if differences appear at the U6 early-detection check-up (10th to 12th month of life) or parents voice concerns, a further examination should take place between the 16th and 18th month. ^{[1, Rec. 8]}

Between 12 and 18 months

The guideline recommended considering the possibility of an autism spectrum disorder and checking it with a suitable screening method if parents report, or the examination shows: ^{[1, Rec. 9]}

• absent or reduced following of another person’s gaze,
• lack of or no eye contact,
• rare or absent pointing with the finger to draw someone’s attention to something,
• weakened or absent response when called by their own name,
• regression or loss of skills already acquired in language or social interaction,
• growing parental concern about development.

If the suspicion is confirmed, the child should be referred without delay to a specialist centre for autism. ^{[1, Rec. 9]}

Between 18 and 24 months and afterwards

If there are differences in following gaze or in pretend play, the suspicion should be checked with a screening method (observable at the U7 early-detection check-up). In addition, further assessment can be considered for: little eye contact, no “bringing to show”, little pointing, weak response to their name, no facial reaction to others’ expressions of pain, regression and parental concerns. ^{[1, Rec. 10]} From the age of 24 months, the guideline named, among others, lack of eye contact, no bringing to show, little pretend play, no pointing and regression (at the U7 to U9 check-ups). ^{[1, Rec. 11]}

For Asperger syndrome (a term from the ICD-10 of the time; today it falls under autism spectrum disorder), prospective studies were lacking. In retrospect, about half of parents said they had already been worried before the third birthday; named were, among others, little or unusual contact, fear of change, sensory differences, restricted imaginative play and little sharing. These features were less specific. ^{[1, Ch. B.2.6]}

Important to know: limits of these signs

• Good eye contact and smiling do not rule out autism. The guideline cited, as a strong recommendation of the British source guideline, not to rule out autism merely because good eye contact, smiling and affective responses towards family members are observed. ^{[1, Ch. B.2.2]}
• Not all children stand out early. About 20 to 25 % of children later diagnosed with autism initially showed no differences in social interaction and communication at 6 to 24 months. ^{[1, Ch. B.2.1]}
• Differences are not always autism. Some siblings of children with autism showed differences at 12 months but had no autism diagnosis at 3 years. Several of the features mentioned also occurred in children with other developmental delays. ^{[1, Ch. B.2.1, B.2.5.3]}
• The evidence was weak: The British guideline rated the quality of the studies as “very low”; the guideline included studies with small numbers. ^{[1, Ch. B.2.2, B.2.5]}
• No marker: There are no reliable biological markers (for example head circumference). ^{[1, Ch. B.2.4]}

What parents can do

1. Take concerns seriously and raise them, for example with the paediatrician or at an early-detection check-up. According to the guideline, parental concerns should be taken seriously. ^{[1, Ch. B.2.2]}
2. Write down observations (practical tip from the editorial team, not from the guideline), for example what, when and in what situation.
3. Have further steps clarified: a screening, then if appropriate a full assessment at a specialist centre. Process: How an autism assessment works and Assessment in children: who, where, how?.
4. Early help is available even without a diagnosis: The guideline named the “Frühe Hilfen” (early help services, from pregnancy and in the first three years of life) as a way of recognising differences. ^{[1, Ch. B.2.6.1]} On support: Early intervention in autism.

What else you should know

• Behaviour can be misinterpreted. The guideline pointed out that behavioural differences in autism are not infrequently interpreted at first as pronounced defiance. ^{[1, Ch. B.2.6.1]}
• Signs for older children and adults: This article covers only the first years of life. On adults: Assessment in adulthood.
• Not covered: Online checklists or tests. They are no substitute for a professional assessment; on screening methods: ADOS-2, ADI-R and screening.

Sources and literature

1. DGKJP, DGPPN et al. Autismus-Spektrum-Störungen im Kindes-, Jugend- und Erwachsenenalter. Teil 1: Diagnostik. S3-Leitlinie, AWMF-Reg.-Nr. 028-018, Textstand 23.02.2016 (Kap. B.2, Empf. 8–11). – Guideline (in German) (expired; according to the document note under revision)
2. DGKJP. Aktuelle Leitlinien (Eintrag 028-018: „Gültig bis 04.04.2021“). https://www.dgkjp.de/wissen/aktuelle-leitlinien/ – Professional society (website in German)