Problems controlling emotions – which can be expressed as depression, anxiety and explosive outbursts – may be a core symptom of attention deficit hyperactivity disorder, Cambridge scientists have shown.
The team found as many as half of all children with ADHD show signs of emotional problems, and Ritalin – the commonly prescribed drug to help ADHD – appears less effective at treating this. ADHD affects around one in 14 young people and in around half it persists into adulthood. The condition causes problems including hyperactivity, impulsivity and difficulty in focusing attention.
However, one in 50 (2.1%) children with ADHD also has a mood disorder, such as depression, while more than one in four (27.4%) suffer with anxiety. Many also have verbal or physical outbursts due to an inability to control their emotions. The researchers examined data from the American ABCD Study, that tracks brain development and mental health of US children. Data on children with ADHD was available for just over 6,000 of these children. A team of scientists from Fudan University in Shanghai, China, and Cambridge University identified 350 teens who scored highly for ADHD. Two thirds (65.7%) of them were male.
The researchers found half (51.4%) of the teens in the high-symptom group showed lack of emotion control. Brain imaging revealed a particular region of the brain known as the pars orbitalis was smaller among these children. The pars orbitalis is at the front of the brain and is important for processing emotion and communication as well as control over behaviour, which may explain some of the behaviours seen in ADHD.
Professor Barbara Sahakian, from Cambridge University, said: “The pars orbitalis is a well-connected part of the brain, and if it hasn’t developed properly it might make it difficult for individuals to control their emotions and communicate with others appropriately, especially in social situations.”
Importantly the researchers found Ritalin, the drug often used to help manage ADHD symptoms, doesn’t appear to fully treat the emotion disturbance (dysregulation). Identifying the problem earlier would help a child better manage their emotions even into adulthood.
Professor Qiang Luo, from Fudan University, said: “Teaching vulnerable individuals from an early age how to manage your emotions and express yourself could help them overcome such problems further down the line.” Importantly, the researchers found signs of a link to the immune system, with teens who had emotion dysregulation having increased numbers of immune cells. Professor Sahakian added: “We already know that problems with the immune system can be linked to depression, and we have seen similar patterns in individuals with ADHD who experience emotion dysregulation.”