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Dementia is an organic brain disorder characterized by impaired cognition involving memory and judgment. Paranoia and disturbances of higher cortical function are common. Changes in personality and behavior frequently occur.

Dementia is generally a progressive disorder which passes through stages of mild to moderate to severe. Only drivers with dementia in the mild stage may still have preserved cognitive functions necessary to safely operate a motor vehicle. The department may receive a report of dementia from a variety of sources, including physicians, law enforcement agencies, and relatives of the driver.Regardless of the source of the information (form or letter), the department must follow up by sending the reported driver the Driver Medical Evaluation, except in situations where an immediate action is taken. An action will not be taken by the department against the driving privilege without receiving information from a physician. If the driver fails to submit the required medical information, the driving privilege will be suspended pursuant to Vehicle Code Section 13801.

The stages are defined below to assist in understanding how a person's daily living activities and driving abilities are affected. Similar definitions are included on the Driver Medical Evaluation (form DS 326) to help all physicians provide the department with consistent evaluations.

Mild Dementia: The capacity for independent living, including adequate personal hygiene and judgment, remains relatively intact. Work or social activities are, however, significantly impaired. Cognitive skills necessary for safe driving, including attention, judgment, and memory, may be significantly impaired.

All drivers who have been referred to the department or diagnosed with mild dementia are scheduled for a driver safety reexamination interview. The driver is given a written knowledge test and reexamined by a hearing officer to assess cognitive deterioration. (Applicants who previously took oral exams may be given an oral exam.)If the written test was passed and the reexamination interview determined that it would be appropriate, the driver will be given a vision test and scheduled to take a Special Driving Test or Supplemental Driver Performance EvaluationIf the driving test was satisfactory, a calendar reexamination is scheduled requiring the driver to return to the department within 6 to 12 months so that the dementia can be reassessed, since a mild stage of dementia can rapidly progress to moderate or severe.

Moderate: Independent living is hazardous and some degree of supervision is necessary. The individual is unable to adequately cope with the environment. Appropriate interpretation of what is seen may be significantly impaired, causing poor or delayed judgment and reaction. Driving would be dangerous.

Severe: Activities of daily living are so impaired that continual supervision is required, e.g., unable to maintain minimal personal hygiene; largely incoherent or mute. The individual is mentally and physically incapacitated.

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How Moderate and Severe Dementia Affect Driving

People with moderate or severe dementia will not be able to safely operate a motor vehicle because their driving skills and physical and mental abilities have deteriorated in the following ways:

  • Consciousness: Inability to respond rationally to the environment. For example, what is seen is not comprehended. This can lead to serious accidents.
  • Cognitive Processing: Unable to remember destination. Inattentive to external stimuli such as pedestrians or oncoming traffic. Judgment is slow or poor in traffic situations.
  • Strength and Coordination: Muscle control is weak and reflexes are too slow to react appropriately to traffic situations or hazards.

The cognitive and physical abilities of drivers who have been diagnosed with moderate or severe dementia will have deteriorated to such an extent that driving would be unsafe, and their driving privilege will be revoked.

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Reexamination is only appropriate for drivers whose dementia is still diagnosed as mild. Drivers with a medical diagnosis of moderate to severe dementia need no further testing because progression of the disease beyond the mild stage of dementia renders the person unsafe to drive.

In-Person Contact

An in-person contact is needed to assess awareness, cognitive processes, and perception. The driver will be expected to answer general questions such as name, address, or type of insurance, along with questions about the driver's health, medical treatment, driving record, need to drive, daily routine, and the need for assistance with daily activities. Inappropriate use of words (syntax) to answer the questions may identify a deterioration in language processing skills and indicate some impairment of cognitive abilities.

The Knowledge Test

The knowledge test is used to determine the driver's mental competency, cognitive and language skills. The primary reason for giving drivers with mild dementia the knowledge test is to determine if these drivers have deteriorating reading and comprehension skills. If they do, they may also have impaired cognitive and perceptual skills which may impact their ability to safely drive a motor vehicle. Testing the driver's knowledge of the rules of the road is a secondary issue, although still relevant. The hearing officer must determine if a poor score on the knowledge test merely indicates a lack of knowledge, or indicates that the driver has difficulty reading and comprehending the questions.

The following will be considered when evaluating the knowledge test results:

  • How long did it take the driver to complete the written exam?
  • How many questions did the driver miss?
  • Was the driver able to answer the missed questions when verbally restated?
  • Could the driver's knowledge be improved by studying the handbook?

If the driver fails the knowledge test after the questions were restated verbally, and it is determined the driver's failure is due to a lack of knowledge, the driving privilege will be suspended pursuant to Vehicle Code Section 13953.

If the driver is unable to coherently answer the hearing officer's questions during the reexamination, or the driver fails the knowledge test after the questions were restated verbally and medical documentation indicates mild dementia, the driving privilege will be revoked pursuant to Vehicle Code Section 13953. The driver may request a hearing after receiving notice of revocation. The issue to consider at a hearing is whether the driver's cognitive skills and memory are keen enough to proceed safely with a special drive test.

The answers given during the in-person contact, together with the results of the knowledge test, provide the hearing officer with an estimation of the driver's memory and cognitive skills. If the driver is able to coherently answer the hearing officer's questions during the in-person contact and the medical documentation is favorable as it relates to safe driving, the driver will be scheduled for a special drive test or supplemental DPE, which includes vision screening.

Special Drive Test

The special drive test is used in determining the driver's competency and ability in the areas of concentration, perception, attention, and/or judgment. A special drive test or Supplemental Driver Performance Evaluation (SDPE) is only appropriate if a medical diagnosis of mild dementia is given, the knowledge and vision screening tests are passed, and the driver answers questions coherently during the in-person contact with the hearing officer.

If the results of the special drive test are satisfactory, the driver will be scheduled for a calendar reexamination, and appropriate license restrictions may be applied, as guided by the results of the Special Drive Test. Drivers should be reevaluated in 6 months or less when the results of the knowledge and drive tests are marginal and the dementia is not expected to progress rapidly.

Marginal Knowledge Test results are indicated when the driver fails the written test but is able to pass when the questions are restated verbally by the hearing officer. Marginal Special Drive Test or SDPE results are indicated when the drive test errors are noncritical ones that may be corrected with additional training.

A 12-month calendar reexamination period may be more appropriate for drivers whose test results are better than marginal for both the knowledge and drive tests, and the driver's physician has indicated the dementia is not expected to progress rapidly. If the results of the special drive test or SDPE are unsatisfactory, the driving privilege will be revoked pursuant to Vehicle Code Section 13953. The driver may request a hearing after receiving notice of the revocation. It is the hearing officer's discretion to determine whether it is safe to allow the driver to take another special drive test or SDPE.

The attached Dementia Consolidation Table and Glossary of Terms define many different types of dementia, their functional impairments, driving impairments, factors to consider, and licensing options. The table provides guidance in determining appropriate actions to impose after reexaminations, hearings, and interviews with drivers diagnosed with dementia.


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