Children with autism are often first diagnosed at the ages of five or six – and even later for children with ADHD. A major Danish study now documents that deviant development can already be seen during the child’s first two years.

2014.06.24 | Lotte Fisker Jørgensen

76,000 mothers have in the survey been interviewed about the development and behavior of their child, when the child was between six and 18 month old.

Many parents have had suspicions for many years before their child is diagnosed. The largest study in the area thus far now confirms that the first sign of ADHD and autism already shows itself in toddlers:

“My study shows that there were a range of common characteristics that recur in a number of the children who were later found to have ADHD or an autism spectrum disorder. During the first years of their life the children were breastfed for a shorter period of time, says the person behind the study, health visitor and PhD Sanne Lemcke, before continuing:

“In the second year of their life many of the children lacked language skills and development of their motor skills deviated compared to other children of the same age. For example, many of them began to walk later.”

Other early signs of ADHD and autism were that the mothers more often suspected that there were vision and hearing problems, and that the children with ADHD were perceived as being more active than other children of the same age.

Early intervention helps

Sanne Lemcke emphasises that not all children with deviant development subsequently received a diagnosis. Others were diagnosed with ADHD or autism without having demonstrated the traits in development during the first two years.

“The results do not necessarily mean we should diagnose toddlers. But the knowledge we now have about the early development of children with ADHD and autism should be used as part of a much earlier effort. The preliminary studies actually suggest that an early effort has great influence on how competent and self-sufficient the children become later in life,” says Sanne Lemcke.

The study utilised data from the large Danish ’Better Health for Mothers and Children’ study from 1997-2002. Approx. 76,000 mothers were interviewed for the study on their child’s development and behaviour when the child was six and 18 months old. Today these children are aged 11-16 making it therefore possible to identify children diagnosed with ADHD or autism.

Documenting parental intuition

Parents will also benefit from earlier focus on the reasons for the deviant development:

“Many parents have an early intuition that the child’s development is different than expected, but they are often left alone with this worry during the first years of the child’s life. The parents often run into a ‘wait and see’ approach from the professionals they meet - and in many cases this can be the right approach. But we know that many parents of children with these kinds of difficulties are very stressed. By taking care of the problems earlier we can, in some cases, relieve the pressure on the parents so that the family as a whole can thrive more,” says Sanne Lemcke.

ADHD that requires treatment is currently found in around two percent of children in a year group, while the figure for autism is around one percent. A strong increase in the occurrence has been seen in recent years.

Facts about the study

• The study was carried out based on information about children aged six and eighteen months from among approx. 76,000 Danish children.
• A total of approx. 2,000 children were subsequently diagnosed with ADHD.
• Approx. 900 children were subsequently diagnosed with autism spectrum disorders.

Further information

Health Visitor, MPH, PhD student Sanne Lemcke
Aarhus University, Department of Clinical Medicine and
Aarhus University Hospital, Psychiatric Hospital for Children and Adolescents
Tel.: + 45 2424 2024/ +45 7847 3356
sanne.lemcke@ps.rm.dk