ADHD and Autistic Spectrum Disorder

Each case should be assessed on its own merits with regard to the degree of disability and the potential impact on diver safety and ability to care for one’s buddy. The degree of disability can be highly variable between individuals. However, individuals maybe more adept than average in some tasks.

There is little research in this area. ADHD is associated with increased risk of accidents and workplace injuries although a retrospective study of navy divers did not provide statistical evidence that the risk of adverse underwater events is significantly increased in those with ADHD, further sufficiently powered studies being required (1). In another paper the same authors noted ADHD may be over-represented in commercial divers in South Africa and may not necessarily be a contraindication to commercial diving, although the numbers were small and cases were self reported (2).

Screening and advice

A report would be required from the treating physician indicating any adverse effects on day to day living that may also impact on safety critical tasks. It would be useful if the treating physician could address the following questions. A positive response to questions 1 to 5 is required for safe diving. A positive response to questions 6-13 or indication of sedation in response to question 14 is likely to be a contra-indication to diving.

1. Does the individual have the capacity to understand, concentrate and attend adequately to relevant information/stimuli in the environment and social context?
2. Does the individual have the ability to follow instructions?
3. Does the individual have the ability to cope with stress?
4. Does the individual have reasonable time management skills?
5. Does the individual have the capacity to consent?
6. Does the individual have any problems with memory?
7. Does the individual have a diagnosis of learning disability?
8. Does the individual have a diagnosis that includes significant speech or language impairment?
9. Does the individual have co-occurrence of ASD (autism spectrum disorder) and ADHD?
10. Does the individual have any other psychiatric diagnoses (including mental health & personality disorders)?
11. Does the individual have support or adaptations in employment or education?
12. Does the individual have a recorded history of impulsivity?
13. Does the individual have a recorded history of substance misuse (including alcohol)?
14. What medication, if any, is required and is it sedating in the individual?

Those newly diagnosed or relatively immature may have more difficulty in meeting these standards. Diving Medical Referees may need to liaise with a specialist more experienced in neurodiversity and diving in addition to the receiving the required report.

Co-occurrence of ASD (autism spectrum disorder) and ADHD, other psychiatric problems or learning disability have been noted to be likely to be incompatible with independent diving (3). Diving is not advised in the event of poorly controlled ADHD symptoms. Even if medication controls ADHD satisfactorily, diving is not advised if symptoms return as the medication wears off between doses (a phenomenon known as rebound, which sometimes presents with more severe symptoms than usual), unless the periods of good control can be predicted with certainty and diving is only undertaken within those periods. The effect of time zone changes must, therefore, be considered very carefully when travelling prior to diving.

Only a single psychotropic medicine is allowed as more than one psychotropic medicine will increase the risk of potentially dangerous side effects whilst diving and susceptibility to narcosis. The individual should be complaint with medication and therapy (4).

If the consultant’s / GP’s report is favorable, there is no clear contraindication to diving, the candidate’s medication (if any) is stable and they are not suffering any side effects that could interfere with diving or have potential side effects that may be exacerbated by exposure to increased pressure such as sedation, narcosis or arrhythmias, then the Diving Medical Referee can consider certifying for supervised pool based training.

On completion of this training, a report is required from their instructor / trainer to inform the Medical Referee of the diver’s ability to concentrate, learn and implement their learning by undertaking safe diving without a lack of awareness or ease of distraction underwater. An instructor should be asked to comment on whether the student is meeting the standards of the course (as set out by the training agency), whether the student is correctly following the instructions during the training sessions and whether the student is responding correctly to assigned problems/scenarios during the pool training.

If this report is favorable then an open water medical certificate can be considered. Further progress through diver training may need to be undertaken with more support than average to ensure safe diving practice, including assessing ability to cope with stress and to behave in such a way as to not compromise the safety of other divers.

Adjustments or restrictions may be required such as no “no clear surface” diving, no decompression diving or only to dive with more than one experienced buddy depending on the individual circumstances. A depth limit of 20 metres may be advised depending on medication taken to minimise the risk of DCI and the slight theoretical risk that some drugs might increase narcosis. A further report may be required from the diving instructor again depending on the individual case.

It must be understood by applicants that not all Medical Referees will have expertise in dealing with younger age groups or individuals with ADHD or autism spectrum disorder and may feel they would be practising outside their area of expertise such that they would be unable to undertake the assessment in some cases.

References :
1. C.H. Van Wijk and W.A. J. Meintjes, Associations between adverse underwater events and ADHD diagnosis amongst military divers, Journal of Attention Disorders 2019: 1-3.
2. C.H. Van Wijk and W.A. J. Meintjes, Adult ADHD prevalence among commercial divers in South Africa, Diving and Hyperbaric Medicine 2020 June; 50(2): 164-7.
3. Learning disability is likely to be incompatible with independent diving (UHMS Medical Guidance, V1.0, 2020)
4. AL Querido and RA van Hulst, Diving and attention deficit hyperactivity disorder, Diving and Hyperbaric Medicine 2019 Mar; 49(1): 41–47.

Reviewed 19 February 2023