What are the symptoms? ADHD is an impairment of either activity or attention control or both. The problem usually presents as a child who is always on the go, does not settle to anything, has poor concentration, poor ability to organise activities or to engage in tedious activities or tasks requiring sustained mental effort, or who cannot stay still and will not wait for others. Some children (with attention deficit otherwise known AD) do not present the full condition, but only the component of inattentiveness. They are forgetful and disorganised and do not focus their concentration well, but their activity levels are normal or even underactive. Hyperkinetic disorder is a severe subtype of ADHD in which all the problems are present in several situations (both at home and school). In addition, some affected children show underachievement at school, motor clumsiness, poor sleep, social interaction difficulties, autistic-type features (see entry Autism Spectrum conditions), speech and language difficulties (see entry Speech and Language Impairment), discipline problems, temper tantrums, unpopularity, or proneness to have accidents. All these, however, can have other causes too. The IQ of an individual with ADHD can be high, normal, low normal or in the learning disability (see entry Learning Disability) range. What are the causes? There are several causes. Twin studies indicate a very strong genetic contribution. Environmental causes include brain damage, intolerance to certain foods, hearing impairment, and toxic and infective agents during pregnancy (including maternal alcohol consumption and smoking). All of these may interact with psychological stress and social problems to create further behavioural and emotional difficulties. How is it diagnosed? The diagnostic features are: inattentiveness – very short attention span, over-frequent changes of activity, extreme distractibilityoveractivity – excessive movements, especially in situations expecting calm such as classroom or mealtimesimpulsiveness – the affected individual will not wait their turn, acts without thinking, and demonstrates thoughtless rule-breaking behaviour. Inheritance patterns and prenatal diagnosis Inheritance patterns There is a strong inherited contribution. DNA studies have indicated variants of some (including dopamine) genes to be more common in groups of children with ADHD. The significance in individual cases is not yet known. Prenatal diagnosisNone. Is there support? ADDISS Tel: 020 8952 2800Email: firstname.lastname@example.orgWebsite: www.addiss.co.uk A Registered Charity in England and Wales No. 1070827. It provides information, training and support for parents, sufferers and professionals in the fields of ADHD and related learning and behavioural difficulties. ADDISS holds a 3-day national conference each year, bringing together professionals and people living with ADHD. Group details last updated July 2015. Hyperactive Children’s Support Group Tel: 01243 539 966Email: email@example.comWebsite: www.hacsg.org.uk The Group is a Registered Charity in England and Wales No. 277643. It provides information and advice for parents, carers and professionals dealing with hyperactivity and ADHD. Group details last updated December 2014. Information, support and advice is also available from a number of groups supporting mental health conditions (see entry Mental Health).