We would recommend all users of this website should always check with their own driving licence authorities for directive on dementia and in some countries it should be noted that MCI may appear as a stand-alone or included in other medical conditions and the decision for driving licence duration and restrictions may vary accordingly.

In the UK, the DVLA guide for medical professionals (Driver Vehicle Licensing Agency, 2018) states that people with Group 1 licences (car and motorcycle) who have dementia may be able to drive but must notify the DVLA. People with Group 2 licences (bus and lorry) must not drive and must notify the DVLA. 

Mild Cognitive Impairment would appear to fall under the DVLA category of “Cognitive Impairment (not mild dementia)”. In this category, where there is no likely driving impairment, people may drive and need not notify the DVLA. Where there is possible driving impairment, the person may be able to drive but must notify the DVLA.

Dementia is defined as a decline in cognition that prevents the person carrying out their normal activities. There are a range of dementia sub-types, for example, Alzheimer’s disease (McKhann et al., 2011), vascular dementia (O’Brien and Thomas, 2015), dementia with Lewy bodies (McKeith et al., 2017) and frontotemporal dementia (Rascovsky et al., 2011). 

The symptoms of dementia vary greatly between individuals and between dementia subtypes. Common symptoms across many types of dementia include difficulty with memory, concentration and executive function. Dementia can also be associated with neuropsychiatric symptoms, such as depression, anxiety, psychosis and fluctuating cognition. It can also be associated with physical symptoms including autonomic dysfunction (e.g. urinary incontinence, dizziness on standing), impaired co-ordination and impaired mobility.

Mild cognitive impairment describes a decline in cognition that does not significantly affect the person’s ability to carry out their normal activities (Albert et al., 2011). Some people with Mild Cognitive Impairment progress to dementia (about 15% per year of those diagnosed with MCI in Memory Clinics), whereas others do not progress. The management of Mild Cognitive Impairment in clinical services is very variable. Some services offer follow-up to monitor the development of dementia, whereas others do not.

Dementia can affect a range of skills that are vital for safe driving, including executive function, visuospatial function, attention/concentration, reaction times and memory.

Most dementias are progressive, and the person will steadily decline over time. This can result in a person becoming dependent on others for most daily activities and becoming clearly unable to drive. However, it is recognised that in the mild stages of disease, some people with dementia may be safe to drive.

Some dementias can be stable for long periods (e.g. post stroke dementia). Often, driver licensing authorities explicitly recognise this variation in rates of progression in their guidance (Driver Vehicle Licensing Agency, 2018), with licences typically being granted subject to regular review.

The presence of other symptoms that may affect driving ability in dementia should be considered, for example:

• Changes in personality with disinhibition, impulsivity and/or aggression
• Excessive daytime sleepiness and variations in arousal
• Psychotic symptoms such as hallucinations or delusions
• Severe anxiety and/or depression

Potential reported ‘red flags’ to be aware of are changes in driving behaviour such as:

• Any ‘at fault’ accidents or ‘near misses’
• Parking problems/hitting kerbs/scrapes
• Speeding or lack of awareness of speed limits when driving
• Driving excessively slowly
• Delayed reactions to, or poor judgement of, road situations in driving
• Passengers becoming actively involved in managing operational aspects of the journey (‘co-piloting’ e.g. pointing out hazards or traffic light changes)
• Poor control of vehicle or increased hesitations at junctions and roundabouts
• Passengers or drivers no longer feeling safe when in the car
• Consistently getting lost on familiar routes
• Poor insight into how dementia may affect/has affected their driving performance

Dementia is associated with a high risk of other co-morbidities, some of which are related to ageing and others that are directly related to the dementia, for example:

• Sensory deficits e.g. visual and hearing impairment
• Physical impairment e.g. osteoarthritis, stroke-related deficits, peripheral neuropathy and parkinsonism
• Seizures
• Autonomic dysfunction e.g. syncope
• Effects of concomitant drugs e.g. benzodiazepines, opiates and anticholinergic medications

It should be recognised that a number of ‘lower level’ deficits such as loss of muscle strength, sensory deficits or other impairments, that alone would not be sufficient to raise concerns but in combination may make a person’s driving unsafe.

Dementia can affect the planning and execution of motor tasks. Whilst this is typically associated with later stages of disease, recent research has highlighted subtle motor changes in the early and pre-dementia stages of disease.

Some forms of dementia such as dementia with Lewy bodies and Parkinson’s disease dementia are associated with parkinsonism, which may affect driving ability.

Dementia can affect the processing of visual information. Performance on some visual tests (e.g. clock drawing) have demonstrated correlation with driving safety in some studies in dementia, but research findings are mixed.

Dementia can affect all cognitive domains and different dementias preferentially affect different domains, particularly in the early stages. In later stages, multiple cognitive domains are usually affected. 

Alzheimer’s disease is most commonly associated with initial impairment in memory and attention.

Vascular dementia is associated with a range of cognitive deficits, often including slowed information processing.

Dementia with Lewy bodies is associated with visuospatial and attention/executive dysfunction and fluctuating cognitive function.

Frontotemporal dementia is associated with attention/executive dysfunction, along with behavioural disturbance, including disinhibition.

Commonly used cognitive screening tests include the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). There may be a cost associated with the use of these instruments or training in their use.

Memory clinics often use longer cognitive screening tools such as the Addenbrooke’s Cognitive Examination. 

These tests will give an impression of the overall degree of cognitive decline, taking into account the person’s expected cognitive abilities, which are strongly influenced by factors such as level of education. They may also highlight areas of relative weakness in particular cognitive domains. There are no validated thresholds in any cognitive test that provide adequate sensitivity and specificity to be used in isolation to predict fitness to drive in dementia. 

Generally, adaptation maybe suitable for some conditions however for dementia and MCI it might be difficult for clients to get used to adaptations due to their difficulty with learning new skills.  However, it is possible that adaptation through driving in their own geographical area might facilitate independent community mobility if they have suitable support to ensure they are adhering to the geographical areas they are permitted to drive within.

As Dementia and MCI are cognitive conditions, usually there is no requirement to consider vehicle adaptations.  However, these conditions can coexist alongside other medical conditions such as Arthritis, Parkinson’s Disease, etc and a person may already be driving an adapted vehicle.  In some cases, a person with a diagnosis of Dementia or MCI may have difficulty operating their usual vehicle controls but this is usually as a result of a decline in their cognition.  

Changing to a vehicle with automatic transmission can help in some cases by reducing cognitive load, but if the person has never driven a vehicle with automatic transmission then consideration will need to be given to their ability to adapt to this change click here to read more.  It is important to give this careful consideration as there has been cases when a driver has become distracted when driving an automatic vehicle e.g. attempting to move the automatic gear selector mistaking it for a gearstick, resulting in significant driving risk which they may not be aware of due to reduced divided attention skills.  An on-road assessment of reasonable duration may allow assessment of whether safe adaptation to the automatic transmission can be achieved.  

If a person has another medical condition and requires vehicle adaptations, again consideration needs to be given to if the client has the ability to learn a new skill.  Usually, if there is a diagnosis of Dementia or MCI, at best, they will struggle to learn new skills as they are unable to retain new information.  If the person has been driving an adapted vehicle before a diagnosis of Dementia or MCI then this should not cause any problems, provided there are no changes made to the adaptations being used.  

Dementia presents in very different ways in different people, but common issues relevant to driving include difficulty with sustained attention, lane position, stopping and decision making (Barco et al., 2015). Consideration should be given to any disproportionate weakness on cognitive testing (e.g. visuospatial function). Crash risk for drivers with Dementia is increased as a result of memory impairment, poor decision making and problem-solving skills, impaired insight and judgment, difficulties with eye hand co-ordination, reduced reaction time and decreased visuospatial abilities (Chee et al;2017).

Although current clinical cognitive assessment tools do not accurately predict actual driving performance, they are useful for screening purposes.  Further research is needed in this area and technology (such as GPS tracking, and other data sensors) may offer assessors of medical fitness to drive support in identifying deterioration in driving ability of patients with dementia (Chee et al, 2017) and develop further guidelines for assessment pathway, driving licence (Varshney, 2020). 

All results including clinic based cognitive assessment results, information from the referring clinician and the initial interview are combined and analysed with the on road practical drive to give an overall assessment of an individual’s ability to drive. The on-road practical drive assesses sequencing, visual-spatial skills, concentration, attention and reasoning ability.

People with dementia may have difficulty in new learning (e.g. the layout of a new car), whereas previously learned material (e.g. they layout in their current car) may be retained. Consideration should be given to this when selecting the vehicle for on-road testing where possible.  Ideally the clients own vehicle would be the most suitable for them, however safety and legal requirements of the assessing team must be considered.

Driving with Dementia or Mild Cognitive Impairment: Consensus Guidelines for Clinicians (2018) Available from: https://research.ncl.ac.uk/driving-and-dementia/ 

In addition to the references in the section above. The following patient information resources provide a rich source of information about a range of different dementias:

Alzheimer’s Research UK: https://www.alzheimersresearchuk.org/dementia-information/ 

Alzheimer’s Society: https://www.alzheimers.org.uk/get-support/publications-factsheets 

Lewy Body Society: https://www.lewybody.org/resources/ 

References

• Albert, M.S., Dekosky, S.T., Dickson, D., Dubois, B., Feldman, H. H., Fox, N. C., Gamst, A., Holtsman, D. M., Jagust, W. J., Petersen, R. C., Snyder, P. J., Carrillo, M. C., Thies, B. & Phelps, C. H. 2011. The diagnosis of mild cognitive impairment due to Alzheimer’s disease: recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement, 7, 270-9.
• Barco, P. P., Baum, C. M., Ott, B. R., Ice, S., Johnson, A., Wallendorf, M. & Carr, D. B. 2015. Driving Errors in Persons with Dementia. J Am Geriatr Soc, 63, 1373-80.
• Driver Vehicle Licensing Agency 2018. Assessing fitness to drive: a guide for medical professionals, London, Department for Transport.
• McKeith, I. G., Boeve, B. F., Dickson, D. W., Halliday, G., Taylor, J. P., Weintraub, D., Aarsland, D., Galvin, J., Attems, J., Ballard, N., Bonanni, L., Bras, J., Brundin, P., Burn, D., Chen-Plotkin, A., Duda, J. E., El-Agnaf, O., Feldman, H., Ferman, T. J., Ffytche, D., Fujishiro, H., Galasko, D., Goldman, J. G., Gomperts, S. N., Graff-Radford, N. R., Honig, L. S., Iranzo, A., Kantarci, K., Kaufer, D., Kukull, W., Lee, V. M. Y., Leverenz, J. B., Lewis, S., Lippa, C., Lunde, A., Masellis, M., Masliah, E., McLean, P., Mollenhauer, B., Montine, T. J., Moreno, E., Mori, E., Murray, M., O’Brien, J. T., Orimo, S., Postuma, R. B., Ramaswamy, S., Ross, O. A., Salmon, D. P., Singleton, A., Taylor, A., Thomas, A., Tiraboschi, P., Toledo, J. B., Trojanowski, J. Q., Tsuang, D., Walker, Z., Yamada, M. & Kosaka, K. 2017. Diagnosis and management of dementia with Lewy bodies: Fourth consensus report of the DLB Consortium. Neurology, 89, 88-100.
• McKhann, G. M., Knopman, D. S., Chertkow, H., Hyman, B. T., Jack, C. R., JR., Kawas, C. H., Klunk, W. E., Koroshetz, W. J., Manly, J. J., Mayeux, R., Mohs, R. C., Morris, J. C., Rossor, M. N., Scheltens, P., Carrillo, M. C., Thies, B., Weintraub, S. & Phelps, C. H. 2011. The diagnosis of dementia due to Alzheimer’s disease: recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement, 7, 263-9.
• O’Brien, J. T. & Thomas, A. 2015. Vascular dementia. Lancet, 386, 1698-706.
• Rascovsky, K., Hodges, J. R., Knopman, D., Mendez, M. F., Kramer, J. H., Neuhaus, J., Van Swieten, J. C., Seelaar, H., Dopper, E. G., Onyike, C. U., Hillis, A. E., Josephs, K. A., Boeve, B. F., Kertesz, A., Seeley, W. W., Rankin, K. P., Johnson, J. K., Gorno- Tempini, M. L., Rosen, H., Prioleau-Latham, C. E., Lee, A., Kipps, C. M., Lillo, P., Piguet, O., Rohrer, J. D., Rossor, M. N., Warren, J. D., Fox, N. C., Galasko, D., Salmon, D. P., Black, S. E., Mesulam, M., Weintraub, S., Dickerson, B. C., Diehl-Schmid, J., Pasquier, F., Deramecourt, V., Lebert, F., Pijnenburg, Y., Chow, T. W., Manes, F., Grafman, J., Cappa, S. F., Freedman, M., Grossman, M. & Miller, B. L. 2011. Sensitivity of revised diagnostic criteria for the behavioural variant of frontotemporal dementia. Brain, 134, 2456-77.

Useful References, relating to ‘On Road Assessment’:

• Chee, Justin & Rapoport, Mark & Molnar, Frank & Herrmann, Nathan & O’Neill, Desmond & Marottoli, Richard & Mitchell, Sara & Tant, Mark & Dow, Jamie & Ayotte, Debbie & Lanctot, Krista & McFadden, Regina & Taylor, John-Paul & Donaghy, Paul & Olsen, Kirsty & Classen, Sherrilene & Elzohairy, Yoassry & Carr, David. (2017). Update on the Risk of Motor Vehicle Collision or Driving Impairment with Dementia: A Collaborative International Systematic Review and Meta-Analysis. The American Journal of Geriatric Psychiatry. 25. 10.1016/j.jagp.2017.05.007.

Dr Paul Donaghy, Ms Kirsty Olsen, Professor John-Paul Taylor, Newcastle University 

Dr Anu Varshney, South East DriveAbility for the On Road Assessment section