Theory of mind comprises thought processes that enable the behaviour and experiences of others to be recognized, understood, predicted and communicated. People with autism have great problems with theory of mind and can often find it hard to recognise people's emotions from their faces. Children with Attention Deficit Hyperactivity Disorder (ADHD) also find it hard to match facial expressions to emotions. Autism can be accompanied by increased inattention, hyperactivity and impulsivity and genetic, neuropsychological and brain-imaging studies suggest links between autism and ADHD. A German study of 99 children between the ages of 6 and 18 found that 52% of the autistic children also met the criteria for a diagnosis of ADHD. The children with ADHD were worse at recognising facial expressions than a healthy control group and both the children with pure ADHD and pure autism were worse than average at recognising emotions.
Sinzig, Judith, Morsch, Dagmar and Lehmkuhl, Gerd - Do hyperactivity, impulsivity and inattention have an impact on the ability of facial affect recognition in children with autism and ADHD? European Child and Adolescent Psychiatry 2008, 17, 63-72