ADHD is common in people with autism. If someone has ADHD, they have significant difficulties with things like poor attention, over-activity and impulsiveness. We asked experts from The South London and Maudsley Hospital to explain how ADHD can affect children and adults, and the options for treatment.

By Dr Anastasios Galanopoulos and team. This information is drawn from an article that first appeared in Your Autism Magazine, Vol 49(1), Spring 2015.

ADHD can cause difficulties at school, work or home – but it is treatable. If you have autism and think that you may also have ADHD, it’s important to have an assessment with a specialist doctor who is familiar with both conditions. They will then be able to discuss your assessment and the treatment options.

What are the symptoms of ADHD?

There are three main types of ADHD; Combined (both inattentive and hyperactive-impulsive), Predominantly Inattentive and predominantly Hyperactive-Impulsive.

Inattention includes things like:

  • lack of attention to detail, making careless mistakes
  • difficulty sustaining attention (eg in class or at work)
  • not listening when spoken to directly
  • having trouble completing jobs and tasks
  • having problems organising tasks
  • avoiding or disliking sustained mental effort (eg filling out forms)
  • losing things
  • being easily distracted
  • being forgetful in daily activities.


Hyperactivity includes things like:

  • being fidgety (hands or feet) or squirming in seat
  • leaving seat when not supposed to
  • being inappropriately restless or overactive
  • having difficulty engaging in leisure activities quietly
  • always being “on the go”
  • talking excessively.


Impulsivity includes things like:

  • blurting out answers before the person’s finished asking the question
  • having difficulty waiting in line or with taking turns
  • interrupting others.


Although we all may do some of these things from time to time, the key thing for ADHD is that in order to reach diagnostic criteria:

  • you do a lot of them
  • they occur across your everyday life
  • the symptoms are out of keeping with your developmental level (eg not behaviours that you’d expect from a 10 year old or a 45 year old)
  • some symptoms that cause difficulties must have been present before 12 years of age (ie they don’t just start in your 30s)
  • the symptoms cause problems in two or more everyday settings
  • there is significant impairment in social, school or work functioning because of these difficulties.


It can be difficult for some people with autism to describe symptoms that they may be experiencing, so it can be helpful to think of how you may behave or react to routine things in your everyday life.

Some examples of behaviours that can be associated with ADHD include:

  • disorganisation (not planning ahead)
  • forgetfulness (missing appointments, losing things)
  • procrastination (starting projects but not completing them)
  • time management problems (always being late)
  • premature shifting of activities (starting something but quickly getting distracted by something else)
  • impulsive decisions (especially around spending, taking on projects, travelling, jobs or social plans)
  • criminal offences (speeding, road traffic accidents, illegal drugs)
  • unstable jobs and relationships.

Does ADHD only happen in childhood?

ADHD used to be thought of as something that happened just in childhood. However, it is now recognised that ADHD can persist to adulthood for many people and can cause adults significant difficulties (eg having to repeat a year at college despite academic ability, difficulty in retaining jobs, difficulty in organising household jobs like bills, payments, shopping and road traffic accidents) if not treated.

How is ADHD treated?

Treatment for ADHD includes both medication and psychological strategies. The National Institute for Health and Care Excellence (NICE) recommends that the first steps in treatment for ADHD for young people include help with behaviour and stress management and educational support and that children under school age should not be given medication for ADHD. For adults with ADHD, NICE recommends that medication is the first-line of treatment, unless the person would prefer psychological treatment.


Medication for ADHD in the UK often includes stimulant medication, such as methylphenidate or a tablet called atomoxetine. Methylphenidate is licensed for use in the UK as part of a comprehensive treatment programme for ADHD, under the supervision of a doctor who specialises in ADHD. Methylphenidate starts to work 30-45 minutes after you’ve taken it, so you and your family and doctor may want to think about when’s best to take it – for example, perhaps just before you leave the house for school or work, so you get maximum benefit once you arrive. Methylphenidate comes in two different formats, immediate and modified release, which allows people some flexibility and choice in how they prefer to take it.

Immediate-release tablets (Ritalin and Equasym) work for up to four hours and so are usually taken two or three times a day. Modified-release methylphenidate, such as Concerta or Equasym, works for up to eight hours and so can be taken just once a day. Atomoxetine is another type of medication for ADHD and is licensed in the UK for the treatment of ADHD in children six years and older, again under specialist supervision. Like with any medication, the pros and cons should be carefully discussed with your doctor before you start them. Also, your doctor will want to check your physical health and monitor your blood pressure. If you’ve taken methylphenidate for a month and it hasn’t helped, it should be stopped. People with autism can be vulnerable to the side effects of medication and so we would recommend that you start with a low dose and if you need to increase the dose, you and your doctor plan to do this slowly over time. 

Specialised therapy

Cognitive behavioural therapy (CBT) can be helpful for ADHD. CBT can also be helpful for things like anxiety and low mood. However, we would recommend that if you have CBT for ADHD, you receive specialised CBT that is specifically adapted for people with both autism and ADHD and is provided by professionals who are experts in both conditions. Information about autism and ADHD (psychoeducation) and social skills work can also be helpful for people with autism and ADHD. Your psychologist or doctor may also suggest some things that might help at work or at school, like setting reminders about homework or jobs on your phone or using a diary (online or paper) to plan your homework or household jobs.

Moving from child to adult services

There are very few specialised mental health services for adults with both autism and ADHD in the UK. As such, some people may not have had an assessment of autism or ADHD until late in their adult life, or have difficulty in accessing treatment. Also some young people with autism and ADHD may have no local adult mental health team to transition to when they leave the care of their paediatrician or child and adolescent mental health service (CAMHS).

If you have no local adult autism or ADHD service, or you are transitioning from child to adult health care, ask your GP, paediatrician or CAMHS team to refer you to a specialised adult autism and ADHD mental health team. It’s helpful if your young person’s team can plan your transition with you before you leave their service, so your care is planned and you, your child and adult teams and GP are clear about how you can access care as an adult.

Find out more at ADDISS, YoungMinds, The ADHD Foundation and AADDUK (a site by and for adults with ADHD).

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Last reviewed: 6 January 2016