Evaluation of Personality & Behaviour Changes


During an initial evaluation, medical professional try to determine whether symptoms are due to a mental or physical disorder.

The following information can help individuals decide when a medical professional’s evaluation is needed and help them know what to expect during the evaluation.

Warning Signs

In individuals with changes in personality or behaviour, certain symptoms and characteristics are cause for concern.

These warning signs include

  • Symptoms that appear suddenly;
  • Attempts to harm themselves or others or threats to do so;
  • Confusion or delirium;
  • Fever;
  • Severe headache;
  • Symptoms that suggest malfunction of the brain, such as difficulty walking, balancing, or speaking or vision problems; and/or
  • A recent head injury (within several weeks).

When to see a Medical Professional?

Individuals who have warning signs should be seen by a medical professional as soon as possible. Law enforcement may need to be called if the individual is violent (which can be for their own and/or others safety).

Individuals who have no warning signs should see a medical professional within a day or two if the personality or behaviour change was recent. If the change occurred gradually over a period of time, the individual should see a medical professional as soon as is practical, but a delay of a week or so is not harmful.

What the Medical Professional Will Do

A medical professional will first ask questions about the individual’s symptoms and medical history.

The medical professional will then perform a physical examination, including a:

  • Neurologic examination; and
  • Mental status examination.

These evaluate the ability to pay attention, memory, and mood among other things.

What the medical professional finds during the history and physical examination often suggests a cause of the changes and the tests that may need to be done.

Questions Individual’s May Be Asked (and Why)

Questions include when symptoms began.

  • Many mental disorders begin in a person’s teens or 20’s.
  • If a mental disorder begins during middle age or later, especially if there is no obvious trigger (such as loss of a loved one), the cause is more likely to be a physical disorder.
  • A physical disorder is also more likely to be the cause when mental symptoms change significantly during middle age or later in people with a chronic mental disorder.
  • If changes began recently and suddenly in individuals of any age, the medical professional will ask about conditions that can trigger such changes.
  • For example, they ask whether the individual has just started or stopped taking a prescription drug or a recreational (usually illegal) drug.

Doctors ask about other symptoms that may suggest a cause, such as:

  • Palpitations: Possibly an overactive thyroid gland or use or withdrawal of a drug.
  • Tremors: Parkinson disease or withdrawal of a drug
  • Difficulty walking or speaking: Multiple sclerosis, Parkinson disease, stroke, or intoxication from an opioid or a sedative.
  • Headache: Brain infection, brain tumour, or bleeding in the brain (haemorrhage).
  • Numbness or tingling: A stroke, multiple sclerosis, or a vitamin deficiency.

The individual will also be asked whether they have previously been diagnosed and treated for a mental or seizure disorder.

  • If they have been treated, the medical professional will ask whether they have stopped taking their drugs or decreased the dose.
  • However, because individuals with mental disorders may also develop physical disorders, medical professionals do not automatically assume that any new abnormal behaviour is caused by the mental disorder.

A medical professional will ask about:

  • Physical disorders the individual may have (such as diabetes).
  • Their lifestyle, such as: their marital status; job situation; educational background; use of alcohol and recreational drugs; and living arrangements.
  • Whether family members have had any physical disorders that can cause mental symptoms, for example, multiple sclerosis.

The Physical Examination

During a physical examination, the medical professional will look for signs of physical disorders and changes in mental status, particularly:

  • Fever:
    • Suggesting an infection, alcohol withdrawal, or use of amphetamines or cocaine in high doses.
  • A rapid heart rate.
  • Confusion or delirium.
  • Abnormalities during the neurologic examination.

Confusion and delirium are more likely to result from a physical disorder. People with mental disorders are rarely confused or delirious. However, many physical disorders that cause changes in behaviour do not cause confusion or delirium, but they often cause other symptoms that may appear to be a mental disorder.

  • If the medical professional bend the individual’s neck forward and, in doing so it is difficult or painful, meningitis may be the cause.
  • The medical professional may check the legs and abdomen for swelling, which may result from kidney or liver failure.
  • If the skin or whites of the eyes look yellow, the cause may be liver failure.
  • The medical professional may examine the interior of the eyes with a handheld device that looks like a small flashlight (called an ophthalmoscope).
  • If they see swelling in part of the optic nerve (papilledema), pressure within the skull may be increased, and tumours or bleeding in the brain may be the cause of the mental symptoms.

Medical Tests

Typically, tests include the following:

  • Measurement of the oxygen level in the blood using a sensor clipped to the person’s fingertip (called pulse oximetry).
  • Blood tests to measure sugar (glucose) levels.
  • Blood tests to measure levels of alcohol and levels of any anticonvulsants the person is taking.
  • Urine tests to check for drugs.
  • A complete blood count (CBC).

For most individuals known to have a mental disorder, no further testing is needed if their only symptoms are worsening of their typical symptoms, if they are awake and alert, and if results of these tests and their physical examination are normal.

For most other individuals, blood tests to check for HIV infection may be performed.

Some medical professionals also routinely do blood tests to measure electrolyte levels and to evaluate kidney function.

Other tests are done based mainly on the symptoms and examination results. Tests may include

  • Computed tomography (CT) or magnetic resonance imaging (MRI) of the brain: If symptoms of mental dysfunction have just appeared or if the individual has delirium, a headache, a recent head injury, or any abnormality detected during the neurologic examination.
  • A spinal tap (lumbar puncture): If the individual has symptoms of meningitis or if results of CT are normal in people with a fever, a headache, or delirium.
  • Blood tests to evaluate thyroid function: If the individual is taking lithium, has symptoms of a thyroid disorder, or is over 40 years old and has personality or behaviour changes that has just started (particularly individuals with a family history of thyroid disorders and women)
  • Chest x-ray: If the individual has a fever or a productive cough or they cough up blood
  • Blood cultures (to check for bacteria in the bloodstream): If the individual is very ill and has a fever.
  • Blood tests to evaluate liver function: If the individual has symptoms of a liver disorder or a history of alcohol or drug abuse or if specific information about them is not available.