I am often asked by Parents or Teachers/Professionals to differentiate between ASD and ADHD symptoms. Many of the Young People I look after have multiple diagnoses and it is impossible to attribute every symptom to each specific condition and sometimes necessary to accept this is the overall different style of thinking of the individual and a holistic approach should be used. What is important however in my daily practice is to ascertain is it solely ASD or ADHD in the Young Person or is there an additional diagnosis as it is important that the right label is given so the Young Person and family access the right support. If I am treating an individual for ADHD with stimulant medication then I need to have screened for possible ASD features which may be unmasked/heightened on commencing medication. Equally there will be little benefit from stimulant medication if the diagnosis is Autism and not ADHD. Around 60% of the children I see will have more than one diagnosis.

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Similarities between Autism and ADHD

Both conditions may result in the Child presenting with inattention, difficulty following instructions, difficulty completing work in School or at home and failing to meet their academic potential. This can lead to frustration, low self esteem and low mood. Hyperactivity and distractibilty may be a feature of both conditions but for different reasons. Children with either condition may have difficulty maintaining friendships (again for different reasons),be rejected by their peers, regularly be in trouble for not responding appropriately to certain situations or presenting with oppositional behaviours. Organisational issues, difficulties competing in team sports and anger management issues are common in both conditions. Anxiety, low mood and obsessive compulsive disorder may again be features of both conditions. In both conditions the Child can hyperfocus in certain settings eg on a 1-1 basis, highly stimulating activities, novel and fascinating circumstances or for scary/thrilling situations. A learning difficulty may also be present in both conditions. All of these difficulties result in Parents, Friends and teachers struggling to manage on a day to day basis.

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Similar Positive features may be present as a result of both conditions such as a passionate interest in their own hobbies, a creative/inventive personality and the ability to think outside the box.

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Differences between Autism and ADHD

Adjusting to changes and transitions

• ASD - 

  • Prefer sameness due to cognitive deficits which limit abilities to adapt spontaneously.

  • These young People are more likely to experience change as anxiety provoking.

  • They can become overstimulated. 

• ADHD- 

  • Tend to prefer change and novelty but have difficulty realigning their behaviour in changing circumstances. 

  • Describe change as exciting and tend to like highly stimulating activities.

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Inattention and distractibility

• ASD

  • Problems with planning and shifting attention rather than sustaining attention and distractibility.

  • Distracted by objects and movement of objects more often than people.

  • Attend to atypical stimuli and therefore appear inattentive.

  • Idiosyncratic focus of attention

  • Attend more to inanimate and spatial characteristics of environment stimuli rather than social features

  • Prone to tune out due to difficulties in mentally imposing organisation in their environment.

• ADHD

  • Also distracted by trivial and auditory stimuli but more distracted by people​

  • Can attend to stimuli that most young people can find compelling

  • Tune out because of mental fatigue or have missed too many pieces of info to make sense of input.

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Repetitive Behaviours

• ASD

  • Restless due to sensory issues such as light, noise, uncomfortable clothes.​

  • Often represent a self-stimulatory behaviour and more often has an unusual quality.

  • Fidgeting may be related to stereotypical movements.

  • Self injurious behaviour

• ADHD

  • Often represents a discharge of energy to permit greater mental awareness​

  • Less unusual in appearance

  • Behaviours such as foot tapping or chewing

  • Distracted and restless due to boredom

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Responses to incentives/reinforcement

• ASD

  • More difficult to find out exactly what they find reinforcing (may be unusual)​

  • Often prefer to stick with the same reinforcer, after some time they may suddenly find it no longer rewording

• ADHD

  • More typically respond to reinforcers that make sense​

  • Need reinforcers/incentives/feedback immediately

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Response to Rules

• ASD

  • Tend to like rules, helps them bring order​

  • Rules in the game tend to be more important than social aspect of game

  • Moralistic quality

• ADHD

  • Not so fond of rules, may have difficulty conforming to rules due to impulsivity​

  • May stretch the rules as much as possible

  • Benefit from structure and routine at home and in school but also benefit from flexibility when it comes to their distractibility

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Cognitive Markers

• ASD

  • More often rigid binary thinkers​

  • Tend to see parts over wholes

  • Difficulty distinguishing fact from fiction

  • Often proficient academic skills - maths, vocab, memory

  • Porr episodic memory, problems re-experiencing the feeling of an event and encoding it with what actually happened to come up with a unique personal meaning

• ADHD

  • Thinking more chaotic​

  • Sees bigger picture and not as good with detail

  • Thinks outside box

  • Poor marks often due to careless errors and short term memory problems

  • No problems with autobiographical memory but short term memory often a problem

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Social Skills and Relationships

• ASD

  • More "odd" in appearance​

  • Social relatedness problems arise from difficulties reading non verbals to regulate social interactions

  • Social skill deficit (naturally don't know what to do)

  • Often target of bullying/teasing

  • Often egocentric

  • Can be naive

  • Talk at peers instead of to them

  • Can be insensitive and lack tact

  • Poor judgement in "social distance"

  • Has well developed speech but poor communication

  • Not always wanting to be part of social world

  • May have trouble building and sustaining friendships

  • TOM - difficulty realising that behaviour affects how other people think and feel

  • Difficulty understanding emotions of others therefore leading to appearance of lack of empathy, can also be overly empathetic

  • Apparent lack of emotion

  • Meltdowns (rigidity, confusion, fear, sensory)

• ADHD

  • Seen as intrusive, noisy, overwhelming due to excessive talking, touching things​

  • Social relations disrupted by problems with impulsivity, turn taking etc which can disrupt flow of social relationships

  • Better grasp of non verbal but difficulties with response inhibition may affect execution of their skills

  • Problems in unstructured times which can lead to them being bullied, fighting or bullying

  • Great desire to be part of social world

  • Performance deficit - can't do what they know

  • Social and boundary problems but natural desire to be social

  • May have trouble building and sustaining friendships

  • TOM less of a difficulty unless overly impulsive

  • Anger management problems (disinhibited)

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Language and Communication

• ASD

  • Excessive talking related to preoccupation​/area of special interest

  • Non verbals like facial expression often do not match inner feeling states

  • Interrupting more associated with lack of social understanding

  • Pervasive problems in pragmatics (ie using language to accomplish practical goal)

  • May have odd prosody and inflection

  • Difficulties with humour, sarcasm, literal interpretation

• ADHD

  • Social chatting/thinking aloud​

  • One topic to another but intent to communicate clear

  • Usually inner feeling states visible

  • Difficulties modulating emotion

  • Generally no specific problem with pragmatics may be skill at "wearing down adults"

  • Unusual speech patterns are not associated with core diagnostic features

  • Often the class clown and loves jokes

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Remember the main differences between the two conditions are related to the different Social Interaction/Communication styles and ADHD medication does not change the Young Person’s innate Social Skills or Personality/emotions but it can have the potential side effects of lowering mood, causing irritability/angry outbursts or tiredness with certain preparations.

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For Further information

www.livingwithadhd.co.uk

www.addiss.co.uk

www.addni.net

www.psychiatry.org for DSMV criteria for ASD and ADHD

www.autism.org.uk