The Mental Status Exam (MSE)
In actual practice, providers (with the exception of a psychiatrist or neurologist) do not regularly perform an examination explicitly designed to assess a patient's mental status. During the course of the normal interview, most of the information relevant to this assessment is obtained indirectly. This review provides an opportunity to consciously think of the elements contained within the MSE.
In the day to day practice of medicine (and, in fact, throughout all of our interactions) we continually come into contact with persons who have significantly impaired cognitive abilities, altered capacity for memory, disordered thought processes and otherwise abnormal mental status. First and foremost, the goal is to be able to note when these abnormalities exist (you'd be surprised at how frequently they can be missed) and then to categorize them as specifically as possible. If a person seems "odd, confused or not quite right" what do we mean by this? What about their behavior, appearance, speech, etc. has lead us to these conclusions? In some instances, the patient's condition (e.g. markedly depressed level of consciousness, intoxication) will preclude a complete, ordered evaluation of mental status, so flexibility is important. Knowing when to "cut your losses" and abandon a more detailed examination obviously takes a bit of experience! The formulation of actual diagnoses, the final step in this process is, for the most part, beyond the scope of this discussion (I've included two of the most commonly encountered ones at the end of this section as examples). In fact, even if you had the experience and knowledge to generate diagnoses, this still may not be possible after a single patient encounter. The interview provides a "snap shot" of the patient, a picture of them as they exist at one point in time. Frequently, and this applies to the physical examination as well, several interactions are required along with information about the patient's usual level of function before you can come to any meaningful conclusions about their current condition. The components of the MSE are as follows:
- Appearance: How does the patient look? Neatly dressed with clear attention to detail? Well groomed?
- Level of alertness: Is the patient conscious? If not, can they be aroused? Can they remain focused on your questions and conversation? What is their attention span?
- Speech: Is it normal in tone, volume and quantity?
- Behavior: Pleasant? Cooperative? Agitated? Appropriate for the particular situation?
- Awareness of environment, also referred to as orientation: Do they know where they are and what they are doing here? Do they know who you are? Can they tell you the day, date and year?
- Mood: How do they feel? You may ask this directly (e.g. "Are you happy, sad, depressed, angry?"). Is it appropriate for their current situation?
- Affect: How do they appear to you? This interpretation is based on your observation of their interactions during the interview. Do they make eye contact? Are they excitable? Does the tone of their voice change? Common assessments include: flat (unchanging throughout), excitable, appropriate.
- Thought Process: This is a description of the way in which they think. Are their comments logical and presented in an organized fashion? If not, how off base are they? Do they tend to stray quickly to related topics? Are their thoughts appropriately linked or simply all over the map?
- Thought Content: A description of what the patient is thinking about. Are they paranoid? Delusional (i.e. hold beliefs that are untrue)? If so, about what? Phobic? Hallucinating (you need to ask if they see or hear things that others do not)? Fixated on a single idea? If so, about what. Is the thought content consistent with their affect? If there is any concern regarding possible interest in committing suicide or homicide, the patient should be asked this directly, including a search for details (e.g. specific plan, time etc.). Note: These questions have never been shown to plant the seeds for an otherwise unplanned event and may provide critical information, so they should be asked!
- Memory: Short term memory is assessed by listing three objects, asking the patient to repeat them to you to insure that they were heard correctly, and then checking recall at 5 minutes. Long term memory can be evaluated by asking about the patients job history, where they were born and raised, family history, etc.
- Ability to perform calculations: Can they perform simple addition, multiplication? Are the responses appropriate for their level of education? Have they noticed any problems balancing their check books or calculating correct change when making purchases? This is also a test of the patient's attention span/ability to focus on a task.
- Judgment: Provide a common scenario and ask what they would do (e.g. "If you found a letter on the ground in front of a mailbox, what would you do with it?").
- Higher cortical functioning and reasoning: Involves interpretation of complex ideas. For example, you may ask them the meaning of the phrase, "People in glass houses should not throw stones." A few common interpretations include: concrete (e.g. "Don't throw stones because it will break the glass"); abstract (e.g. "Don't judge others"); or bizarre.
Diagnoses are made on the basis of a pattern of responses to the above evaluation. Two commonly occurring disorders are described below:
- Delirium: Also referred to as Altered Mental Status, Delta MS, Acute Confusional State,
or Toxic Metabolic State. This is a very common condition (particularly among
hospitalized patients) notable for an acute, global change in mental status that can be
the result of physiologic derangement anywhere within the body. Causes include:
infection, hypoxia, toxic ingestion, impaired ability of the body to handle endogenously
produced toxins (e.g. liver or kidney failure), etc. There is a wide spectrum of
presentations, ranging from unarousable to extremely agitated. Patients may appear quite
ill, with markedly abnormal vital signs that in themselves can suggest the cause of the
delirium (e.g. hypotension, infection). They are frequently confused, disoriented,
agitated and uncooperative. Formal evaluation of mood, affect, memory, judgment or
insight can be hopeless. Thought process is disordered and content notable for
delusions, paranoia and hallucinations. In general, the diagnosis is suggested by the
time course of the illness (i.e. the change is acute). Treatment is dictated by the
underlying insult, which can generally be determined after a detailed history (usually
with the help of others who are familiar with the patient), review of medications,
thorough examination, and appropriate use of lab and radiologic testing. The elderly as
well as those with multiple medical problems (conditions which frequently coexist) are
at the highest risk for developing this condition. Delirium in this patient sub-set can
be provoked by seemingly minor precipitants. Initial presentation of psychotic disorders
as well as dementia can be mistaken for delirium (and vice versa). This can only be
sorted out with time and appropriate testing, though these distinctions are extremely
For Additional Information See: Digital DDx: Delirium
- Dementia: A final common pathway for multiple disorders characterized by its slow,
progressive nature, taking months to years to develop. While quite uncommon under 50,
the incidence increases markedly with age. Patient's appearance and behavior vary with
the extent of involvement. This ranges from well groomed, alert and cooperative to
agitated, unable to care for themselves and incapable of answering even simple
questions. Mood and affect can range widely, and may or may not be appropriate for the
given situation. Thought process and content have similar variability. Memory, judgment
and higher cortical function deteriorate with time. As this is a progressive disease,
presentation will depend on the level of advancement. Contributions from other acute,
reversible medical problems must be ruled out on the basis of history, examination and
For Additional Information See: Digital DDx: Dementia
The Mini Mental Status Examination (MMSE) is a brief bedside test that is an excellent means of quantifying cognitive function and decline. A newer validated tool for quantifying cognitive performance is the Saint Louis University Mental Status Examination (SLUMS).
Many aspects of the MSE are extremely subjective. There is tremendous potential for our own cultural exposure and background to color these assessments. Realize that there is a major distinction between "different" and "abnormal." Proverbs, for example, are not necessarily a part of any communal experience. Thus, a "failure" to provide a correct interpretation may in fact have nothing to do with an individual's intellectual function but rather may simply reflect a different upbringing or background. Similarly, tests of memory which require the subject to recite past U.S. Presidents may not be an appropriate measuring tool depending on a person's country of origin, language skills, educational level, etc. These situations are unavoidable in the extremely diverse community in which we live. Quantifying and defining the nature of a specific abnormality is an important part of the practice of medicine. While it is reasonable to expect that people be aware of certain basic facts (e.g. their name, the year, the purpose of their visit to the hospital, etc.) it is also important to recognize that our observation and interpretation of patient behavior and responses is colored by our own life experiences.