Assessing Fitness to Drive

Table of Contents

Front matter
Foreword
Part A. Fitness to drive principles and practices
1. About this publication
- 1.1. Purpose
- 1.2. Target audience
- 1.3. Scope
- 1.4. Content
- 1.5. Development and evidence base
2. Assessing fitness to drive – general guidance
- 2.1. The driving task
- 2.2. Impact of medical conditions on driving
- 2.3. Assessing and supporting functional driver capacity
3. Roles and responsibilities
- 3.1. Roles and responsibilities of driver licensing authorities
- 3.2. Roles and responsibilities of drivers
- 3.3. Roles and responsibilities of health professionals
4. Licensing and medical fitness to drive
- 4.1. Medical standards for private and commercial vehicle drivers
- 4.2. Considerations for commercial vehicle licensing
- 4.3. Prescribed periodic medical examinations for particular licensing authorisation classes
- 4.4. Conditional licences
- 4.5. Reinstatement of licences or removal or variation of licence conditions
5. Assessment and reporting process – step by step
- 5.1. Steps in the assessment and reporting process
- 5.2. Which forms to use
References and further reading
Part B. Medical standards
Fitness to drive assessment
1. Blackouts
- 1.1. Relevance to the driving task
- 1.2. General assessment and management guidelines
- 1.3. Medical standards for licensing
2. Cardiovascular conditions
- 2.1. Relevance to the driving task
- 2.2. General assessment and management guidelines
- 2.3. Medical standards for licensing
3. Diabetes mellitus
- 3.1. Relevance to the driving task
- 3.2. General assessment and management guidelines
- 3.3. Medical standards for licensing
4. Hearing loss and deafness
- 4.1. Relevance to the driving task
- 4.2. General assessment and management guidelines
- 4.3. Medical standards for licensing
5. Musculoskeletal conditions
- 5.1. Relevance to the driving task
- 5.2. General assessment and management guidelines
- 5.3. Medical standards for licensing
6. Neurological conditions
- 6.1. Dementia
- 6.2. Seizures and epilepsy
- 6.3. Other neurological and neurodevelopmental conditions
7. Psychiatric conditions
- 7.1. Relevance to the driving task
- 7.2. General assessment and management guidelines2,6,7
- 7.3. Medical standards for licensing
8. Sleep disorders
- 8.1. Relevance to the driving task
- 8.2. General assessment and management guidelines
- 8.3. Medical standards for licensing
9. Substance misuse
- 9.1. Relevance to the driving task
- 9.2. General assessment and management guidelines
- 9.3. Medical standards for licensing
10. Vision and eye disorders
- 10.1. Relevance to the driving task
- 10.2. General assessment and management guidelines
- 10.3. Medical standards for licensing
Part C. Appendices
Appendix 1. Regulatory requirements for driver testing
Appendix 2. Forms
Appendix 3. Legislation relating to reporting
Appendix 4. Drivers’ legal BAC limits
Appendix 5. Alcohol interlock programs
Appendix 6. Disabled car parking and taxi services
Appendix 7. Seatbelt use
Appendix 8. Helmet use
Appendix 9. Driver licensing authority contacts
Appendix 10. Specialist driver assessors
Appendix 11. Search Fitness to Drive resources

7.1 Relevance to the driving task

In this section

7.1.1. Effects of psychiatric conditions on driving

7.1.3. Impairments associated with medication

7.1.1 Effects of psychiatric conditions on driving

Psychiatric conditions may be associated with disturbances of behaviour, cognitive abilities and perception and therefore have the potential to affect driving ability^{1, 2, 3, 4}. They do, however, differ considerably in their aetiology, symptoms and severity, and may be occasional or persistent. The impact of mental illness also varies depending on a person’s social circumstances, occupation and coping strategies. Assessment of fitness to drive must therefore be individualised and should rely on an evaluation of the specific pattern of illness and potential impairments as well as severity, rather than the diagnosis per se. The range of potential impairments for various conditions is described below.

People with schizophrenia may have impairments across many domains of cognitive function including:

reduced ability to sustain concentration or attention
reduced cognitive and perceptual processing speeds including reaction time reduced ability to perform in complex conditions – for example, when there are multiple distractions
perceptual abnormalities – for example, hallucinations that distract attention or are preoccupying
delusional beliefs that interfere with driving – for example, persecutory beliefs may include being followed and result in erratic driving, or grandiose beliefs may result in extreme risk taking.

People with bipolar affective condition may demonstrate:

depression and suicidal ideation
mania or hypomania, with impaired judgement about driving skill and associated recklessness
delusional beliefs that directly affect driving.

People with depression may demonstrate:

disturbances in attention, information processing and judgement, including reduced ability to anticipate
psychomotor retardation and reduced reaction times
sleep disturbances and fatigue
suicidal ideation that may manifest in reckless driving.

People with anxiety conditions (including post- traumatic stress disorder) may:

be preoccupied or distractible
experience panic attacks or obsessional behaviours that may impair driving.

People with personality conditions may be:

aggressive or impulsive
resentful of authority or reckless.

People with attention-deficit/hyperactivity disorder may:

be more prone to angry aggressive and risky driving behaviour
have difficulty in planning, organising and prioritising tasks
have difficulty in sustaining or shifting focus
have difficulty managing frustration, modulating emotions and self-regulation.

These impairments are difficult to determine because impairment differs at various phases of the illness and may vary markedly between individuals. The impairments described above are particularly important for commercial vehicle drivers.

7.1.2 Evidence of crash risk

There is limited evidence about the impact of psychiatric illness on crash risk^{^{1, 3, 4}}. Some studies have shown that drivers with psychiatric illness have an increased crash risk compared with drivers without psychiatric illness. There is also specific evidence for increased risk among those with schizophrenia and personality conditions. The evidence suggests a modestly elevated risk for people with low levels of impairment; however, it is possible that people with higher levels of impairment self-regulate their driving or drive more slowly and cautiously, therefore reducing their risk.

7.1.3 Impairments associated with medication

Medications prescribed for treating psychiatric conditions may impair driving performance⁵. There is, however, little evidence that medication, if taken as prescribed, contributes to crashes; in fact, it may even help reduce the risk of a crash (refer to Part A section 2.2.9. Drugs and driving). Numerous psychotropic medications have been shown to impair perception, vigilance and psychomotor skills. Many medications can produce side effects such as sedation, lethargy, impaired psychomotor function and sleep disturbance. Benzodiazepines have especially been shown to impair vision, attention, information processing, memory, motor coordination and combined-skill tasks. Tolerance to the sedating effects may develop after the first few weeks, although other cognitive impairments may persist. The assessment of medication effects should be individualised and rely upon self- report, observation, clinical assessment and collateral information to determine if particular medications might affect driving. If a person is prescribed stimulants (e.g. dexamphetamine) for treating attention-deficit/hyperactivity disorder, this should be stated in the advice provided to the driver licensing authority.

Health professionals should have heightened concern when sedative medications are prescribed but should also consider the need to treat psychiatric conditions effectively. Refer also to section 9. Substance misuse.