Evaluation of Personality & Behaviour Changes

During an initial evaluation, medical professionals 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/health care practitioner as soon as possible.

Law enforcement may need to be called if individuals are violent.

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 will the Medical Professional Do?

Medical professionals first ask questions about the individual’s symptoms and medical history.

They will then perform a physical examination, including a neurological examination with a mental status examination (which evaluates the ability to pay attention, memory, and mood among other things).

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

Questions Asked

  • Questions include when symptoms began.
    • Many mental disorders begin in an individual’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 individual’s of any age, medical professionals 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.

Other Symptoms

Medical professionals 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.

Individuals are also asked whether they have previously been diagnosed and treated for a mental or seizure disorder. If they have been treated, medical professionals 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 (and should not) automatically assume that any new abnormal behaviour is caused by the mental disorder.

Medical professionals ask about:

  • Physical disorders the individual has, for example diabetes; and
  • About their lifestyle, for example:
    • Marital status;
    • Job situation;
    • Educational background;
    • Use of alcohol and recreational drugs; and
    • Living arrangements.

Medical professionals also ask whether family members have had any physical disorders that can cause mental symptoms (such as multiple sclerosis).

Physical Examination

During a physical examination, medical professionals 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; and/or
  • Abnormalities during the neurological 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.

Other checks during the physical examination include:

  • Bending the individual’s neck forward.
    • If doing so is difficult or painful, meningitis may be the cause.
  • Checking 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.
  • Examination the interior of the eyes with a handheld device that looks like a small flashlight (called an ophthalmoscope).
    • 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.


Typically, tests include the following:

  • Measurement of the oxygen level in the blood using a sensor clipped to the individual’s fingertip (called pulse oximetry);
  • Blood tests to measure sugar (glucose) levels;
  • Blood tests to measure levels of alcohol and levels of any anti-convulsants the individual is taking;
  • Urine tests to check for drugs; and/or
  • 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 are usually done.

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, and these tests may include:

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

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.