The mental status examination (MSE) is an important diagnostic tool in both neurological and psychiatric practice. MSE is used to describe a patient's mental state and behaviors, both quantitatively and qualitatively, at a specific point in time. The main components of an MSE are appearance and behavior, mood and affect, speech, thought process and content, perceptual disturbances, sensorium and cognition, and insight and judgment. The clinician conducting an MSE collects data by observing the interviewed individual's behavior and asking specific questions. The findings of the MSE summarize the results of a psychiatric examination on a comprehensive, cross-sectional level. When integrated with the interviewee's biographical information and psychiatric history, MSE findings form the basis for diagnostic and therapeutic decisions. A thorough MSE also provides essential information for establishing a diagnosis according to DSM-5 criteria.
When conducting the MSE or interpreting MSE findings, it is important to consider the cultural background of both the clinician conducting the MSE and the interviewee because behavioral patterns vary significantly across cultures (e.g., nodding your head as a sign of approval in some countries might signify disagreement in others). Other factors that should be taken into account when conducting an MSE include the religious, educational, and social backgrounds of the interviewed individuals. Similarly, the clinician should be aware of any potential language barriers. The MSE is not to be confused with the Mini-Mental State Examination (MMSE), which is a screening tool for dementia but can also be used as part of the MSE to assess sensorium and cognition.
The MSE is composed of the following components: 
- Abnormalities in appearance can provide insight into an individual's lifestyle and ability to care for themselves.
- Such abnormalities can be the first indicator of a number of psychiatric conditions.
- Individuals with severe depression may present with significant weight loss or appear disheveled.
- A patient with histrionic personality disorder might wear what is considered an inappropriately seductive outfit or excessive makeup, either in the context of the patient's cultural norms or in contrast to how they dressed previously.
- An individual that is currently experiencing a manic or hypomanic episode may present with extremely colorful hair or dress in brightly colored or flamboyant clothing.
- Needle marks or jaundice could indicate substance abuse.
- When assessing a patient's physical appearance, a physician should pay attention to the following features:
- Estimated age by physical appearance: should be compared with the patient's stated age
- Body habitus
- Posture (e.g., open or closed, tense or relaxed)
- Level of grooming (e.g., meticulously shaved or excessively scruffy)
- Presence of body odor and/or halitosis
- Dress: the amount and type of clothing used by the patient, taking into consideration the patient's cultural norms
- Distinguishing features
- Wounds (e.g., burns, scratches, needle marks) and/or scars
- Tattoos and/or body piercings
- Dental braces, jewelry, glasses
- Similar to appearance, the assessment of an individual's behavior can also provide important clues for establishing a diagnosis.
- Psychomotor agitation is commonly observed in individuals experiencing mania, whereas psychomotor retardation is usually seen in individuals with depression.
- Glancing repeatedly at different parts of the room is commonly seen in individuals experiencing auditory or visual hallucinations (e.g., in schizophrenia).
- Abnormal motor activity (movements, gait) can be a sign of an underlying neurological disorder or a side effect of psychotropic medication.
- A physician should pay attention to the following aspects of an individual's behavior:
Disorders of diminished motivation: characterized by impairment in goal-directed behavior, thought, and emotion 
- Because they are not classified as disorders within DSM-5, it is uncertain if they are distinct disorders or symptoms that overlap with other conditions.
- There are three types that vary in severity:
- Apathy: the least severe form of DDM characterized by reduced motivation and/or goal-directed behavior
- Abulia: a more severe form of DDM characterized by diminished in purposeful movements, will, and/or initiative
- Akinetic mutism: the most severe form of DDM characterized by the absence of movements and paucity of speech determined by lack of motivation
Abnormal motor activity
- Abnormal movements: See “Examination of the motor system” and “Muscle appearance” in .
- Gait: See in for more information.
Apraxia: difficulty performing targeted, voluntary movements despite an intact motor function and the willingness to perform the movement
- Ideomotor apraxia: difficulty imitating actions; mismatch between intention and expression (e.g., instead of waving, a patient will scratch his ear)
- Ideational apraxia: difficulty planning and completing multistep actions when interacting with objects
- Constructional apraxia: difficulty drawing or creating objects out of different parts
- Apraxia of lid opening: difficulty voluntarily opening the eyes in the absence of levator palpebrae muscle palsy
- The evaluation of sensorium assesses a patient's level of consciousness and their orientation to person, place, and time.
- Because sensorium impairments can have vital implications, the evaluation of sensorium should be performed at the beginning of the MSE.
Orientation to person, place, and time
- Can be assessed by asking the patient their full name, the current date, and the current location
- Disorientation is a state characterized by the loss of the notion of time, place, and/or space.
Level of consciousness
- Level of consciousness is a person's level of arousability and response to external stimuli (e.g., verbal, painful stimuli).
- It is typically assessed by evaluating the patient's response to external stimuli and can be described using the following:
- A state of awareness of oneself and the surrounding environment
- Considered a normal finding
- A state of drowsiness from which a patient can be easily aroused
- The patient responds normally except for a slight delay when addressed.
- A state of impaired consciousness and drowsiness from which the patient can be awoken if exposed to moderate stimuli 
- The patient has decreased interest in the surrounding environment and tends to fall back asleep after being aroused.
- A state of impaired consciousness characterized by increased sleepiness and a slow response to external stimuli
- Similar to lethargy, the patient has a decreased interest in the surrounding environment and experiences drowsiness between the sleeping episodes.
- A state of insensitivity bordering on unconsciousness; from which the patient is not easily awoken, except if exposed to strong external stimuli,; (e.g., sternal rub) and into which the patient returns in the absence of further stimulation
- Communication is not possible and a painful stimulus provokes a withdrawal response.
- A state of complete unarousable unresponsiveness regardless of the stimulus, typically lasting for 2–4 weeks 
- A comatose state is characterized by closed eyes and decreased/absent reflex responses and motor activity, but preserved circulatory function and breathing drive.
- A quantitative assessment of consciousness is more likely to be used in clinical settings because it provides a more objective assessment of the patient's level of consciousness.
Glasgow Coma Scale (GCS): A common neurological scoring scale used for the evaluation of consciousness in acute settings (especially after head injury) and sometimes for monitoring patients in the ICU.
- Patient's verbal, motor, and eye-opening responses are scored on a scale of 1–6 points; 1 point denotes a complete lack of response and 6 points denotes normal findings.
- See “Diagnostics” in for more information.
Cognition is the mental process of gaining knowledge and understanding via thinking, experiencing, and sensing, and includes many aspects listed below. The assessment of cognitive function during an MSE is usually performed using screening tools such as the MMSE and/or the Saint Louis University Mental Status Examination (SLUMS). (See “Cognitive assessment” in for more information.)
- The ability of an individual to focus and sustain their thoughts on a specific task/topic
- Can be assessed by asking the patient to spell a word backward or count in twos
- The process of recalling information
- Classified according to the length of time a particular piece of information can be recalled.
Sensory (immediate) memory
- The shortest type of information storage
- Can be assessed by asking the patient to repeat a set of numbers or words in the original order
- Information is stored for a few minutes in order to be processed and used while performing a task
- Can be assessed by asking the patients to look at a set of numbers/words/images for a couple of seconds, and then asking them to recall the items 5 minutes later
- Information is stored for days to years
- Can be assessed by asking the patient about an objectively verifiable personal or historical fact (e.g., date of marriage, a former president's name)
- Sensory (immediate) memory
Amnesia: loss of memory
- Retrograde amnesia: inability to recall memories and/or information acquired prior to the incident
- Anterograde amnesia: inability to recall memories and/or information acquired after the incident
- Global amnesia: inability to recall memories and/or information acquired prior to and after the incident
- Confabulation: filling in lapses of memory with fabricated events, without the intention of deceiving the interviewer
- The ability to perform simple calculations, according to the patient's level of education
- Can be assessed by asking the patient to continuously subtract 7 starting from 100
- Acalculia: inability to perform simple calculations (usually a sign of parietal lobe lesions)
- Language: see “Language” section below.
- Fund of knowledge
- The ability to analyze information, detect patterns and connections between different pieces of data, and apply that knowledge to practice
- Can be assessed by asking the patient to find the similarities between objects (e.g., the similarities between a triangle and a square)
- Executive function
- In contrast to speech, language stands for the structured use of words and syntax according to a set of pre-established rules (e.g., grammar, semantics).
- Can be assessed based on the patient's ability to name objects, read, and write
- The most common types of impairment of language include:
- Agraphia: inability to write
- Alexia: a form of visual agnosia with severe reading problems as a result of interrupted connections between the visual cortex and language‑related areas
- Refers to the patient's subjective assessment of their emotions when asked how they feel
- Mood should be described using the patient's own words (e.g., happy, ecstatic, sad, guilty, angry, exhausted, frustrated, frightened) and placed within quotation marks.
- Most psychiatric conditions are associated with some degree of mood alteration.
- Refers to the physician's objective assessment of a patient's emotions conveyed both verbally and nonverbally during an interview
- A comprehensive description of a patient's affect should cover all of the following characteristics:
- Quality: dysphoric, neutral, euthymic, detached, anxious, irritable, hostile, sad, angry, or euphoric
- Congruency: congruent or incongruent with stated mood
- Range: flat, blunted , full, or exaggerated
- Mobility: fixed, constricted, labile, or mobile
- Appropriateness to situation: appropriate vs. inappropriate emotions
- It is important to assess a patient's affect during the MSE because changes in affect are characteristic of a large number of psychiatric conditions.
Speech is the spontaneous production of the spoken language (i.e., the act of speaking ) and is characterized by the following:
- Rate: rapid, normal, slow, or pressured
- Volume: loud, normal, soft, or whispered
- Quantity: logorrheic, talkative, responsive, or reserved
- Articulation and fluency: incomprehensible, accented, stuttered, lisping, mumbled, slurred, clear, or articulated
- Speech latency: increased, decreased, or no latency
- Because speech impairment is characteristic of a large number of conditions, it is an important diagnostic tool.
- Some of the speech abnormalities that can be observed during an MSE include:
- Mutism: an inability to speak that is caused by a structural or motor dysfunction of the vocal apparatus or that is the result of an individual's unwillingness to speak despite having an intact vocal apparatus (e.g., akinetic mutism)
- Dysarthria: the impaired articulation of words resulting from motor dysfunction of the vocal apparatus
- Echolalia: the involuntary repetition of another person's speech
- Palilalia: the involuntary repetition of words or phrases with increasing rapidity
- Alogia/poverty of speech: impaired thinking that manifests with reduced speech output (e.g., always replying to questions with one-word answers)
- Pressured speech: accelerated thoughts that are expressed as rapid, loud, and voluminous speech often in the absence of social stimulation
- Neologisms: the creation and use of new words that are only understood by the speaker (e.g., Pepsidiction = Pepsi + addiction, Spritependency = Sprite + dependency)
Word salad: incoherent thinking expressed as a sequence of words without a logical connection
- Characteristic of schizophrenia and dementia
- Example: “They’re destroying too many cattle and oil just to make soap. If we need soap when you can jump into a pool of water, and then when you go to buy your gasoline, my folks always thought they should get pop but the best thing to get is motor oil and money.” 
- Thought process is the act of thinking and is characterized by the number of thoughts as well as their flow and coherence.
- A physician evaluates a patient's thought process by analyzing the patient's responses to different types of questions when taking their medical history or during their physical examination.
- When describing an individual's thought process, the following terms can be used:
|Circumstantial thought process|| || |
|Tangential thought process|| || |
|Loose associations/derailments|| || |
|Flight of ideas|| || |
|Clang associations|| || |
|Perseveration|| || |
|Thought blocking|| |
- Thought content refers explicitly to what an individual is thinking about (i.e., main themes and beliefs) and is usually evaluated based on the presence of delusions, obsessions, compulsions, phobias, and homicidal or .
- Important because a large number of psychiatric conditions are associated with various disturbances of thought content, some of which are pathognomonic (e.g., suicidal ideation for patients with severe depression)
- Consider the individual's social, cultural, and educational background, since the understanding of normality varies among these things.
- Delusions are fixed, false beliefs (unrelated to one's religious beliefs or culture) that are maintained despite being contradicted by reality or rational arguments.
- All delusions can be classified as either:
- Bizarre delusions: delusions that cannot be true or are inconsistent with the patient's social and cultural norms (e.g., a patient insisting that they can fly)
- Nonbizarre delusions: delusions that could be true or are consistent with the patient's social and cultural norms (e.g., a patient insisting that they have won the lottery when this is not the case)
- Based on their mood congruence, delusions can be classified as either:
- Mood congruent delusions: the content of delusions is consistent with the patient's current mood (e.g., a manic patient insisting they have special powers)
- Mood incongruent delusions: the content of delusions is not consistent with the patient's current mood (e.g., a patient having a manic episode insisting that they are being chased by a murderer)
|Delusions according to their content|
|Type||Description||Assess by asking patient if they:|
|Persecutory delusions|| || |
|Paranoia|| || |
|Grandiosity|| || |
|Erotomania|| || |
|Jealousy|| || |
|Delusion of reference|| || |
|Somatic delusions|| || |
|Religious delusions|| || |
|Delusion of poverty|| || |
|Delusion of guilt|| || |
|Mixed delusions|| |
|Unspecified delusion|| || |
To remember the different types of delusions (Grandiosity, Erotomanic, Ideas of reference, Paranoid, Persecutory, Somatic, Jealousy), think: “Grand, Erotic Ideas can cause Paranoia, Persecution and So much (so-ma-tic) Jealousy.”
Suicidal and homicidal ideation
- Suicidal ideation: any type of thoughts that an individual has regarding ending their own life (see for more details)
- Homicidal ideation: thoughts regarding ending someone else's life
- Ask the patient if they sometimes feel that life is not worth living and if they have ever felt the desire to harm other people.
- Can range from a brief consideration of the act to concrete planning of the time, place, and/or method of suicide/homicide.
- Assess the threat (organized plan, access to weapons).
- Admit the patient involuntarily if they refuse medical care.
- In homicidal threats, inform the authorities and the threatened individual.
- Obsession: A repetitive, persistent, intrusive, and unpleasant thought or urge that causes severe distress and anxiety.
- Compulsion: Ritualistic, repetitive behaviors (e.g., touching, washing) or mental act (e.g., counting, repeating a word silently) carried out in an effort to relieve urges and decrease obsession-related distress.
- Ask the patient if there is something they constantly think about and whether they engage in any specific behavior to get rid of the persistent thoughts
- See for more information.
- A specific phobia is a persistent (≥ 6 months) and intense fear of one or more specific situations or objects (phobic stimuli).
- Some common examples of phobias include agoraphobia (fear of unknown places and situations), claustrophobia (fear of enclosed places), arachnophobia (fear of spiders), and hematophobia (fear of blood).
- Can be assessed by asking the patient whether they are scared of anything and how long this fear has affected them
- See for more information.
Perceptual disturbances are characterized by disruption in perception, which may be caused by physical and/or mental disorders.
- Hallucinations are a type of perceptual abnormality in which sensory experiences occur in the absence of external stimuli.
- Can be assessed by asking the patient if they ever hear, see, feel, smell, or taste things that other individuals do not.
- Some of the most common causes of hallucinations include:
|Types of hallucinations |
|Auditory hallucination|| |
|Visual hallucination|| |
|Somatic (tactile) hallucination|| |
|Sleep hallucinations|| |
- Perceptual disturbances characterized by inaccurate perception (distortion) of real sensory input (e.g., perceiving a stationary object as being in motion)
- Assess by asking the patient whether they sometimes misinterpret real things around them, such as shadows or faint noises
- Similar to hallucinations, illusions can be categorized according to the misinterpreted sensory input as visual, auditory, tactile, olfactory, and gustatory.
- Although illusions are characteristic of some mental disorders (e.g., schizophrenia), most illusions are physiological in nature and generated by each individual's perceptive assumptions based on their psychological profile (e.g., influenced by darkness, fatigue, or under the influence of drugs or alcohol).
- A psychological defense mechanism that is a natural protective response to a traumatic or stressful experience.
- Characterized by disruption and/or discontinuity of normal consciousness, memory, identity, and perception of oneself (e.g., derealization, depersonalization)
- Can be assessed by asking the patient whether they sometimes feel detached from themselves or others or if the world around them sometimes feels unnatural
- See for more information.
- Characterized by impaired recognition of sensory stimulus (most commonly visual) 
- Can be tested by presenting different objects or exposing a patient to different stimuli (depending on recognition of which modality is tested)
- Can still recognize the objects using different sensory modalities (unless multiple senses affected)
- Types include:
- Visual agnosia: inability to recognize visually presented objects despite otherwise normal vision
- Auditory agnosia: inability to recognize sounds despite intact hearing
- Tactile agnosia (astereognosis): inability to recognize objects by touch using texture, shape, and temperature as cues without visual input
Visuospatial dysgnosia: inability to localize and orient oneself and/or identify relationships between objects in the environment
- Often associated with damage to the right posterior parietal area of the brain.
- Prosopagnosia: inability to recognize familiar faces, while the ability to name parts of the face (e.g., nose, mouth) or identify individuals by other cues (e.g., clothing, voices) is left intact.
Autotopagnosia: inability to localize different parts of the body upon request
- Caused by damage to left posterior parietal area of the cortex
Hemineglect (also known as unilateral neglect or spatial neglect)
- Hemineglect is the impaired ability to perceive and respond to different types of stimuli coming from one side of the body usually due to a brain unilateral injury (most commonly strokes).
- Typically associated with right hemisphere damage resulting in neglect (esp. visual) of the left side 
- The lesion is usually contralateral to the side where the perception is absent
- Can be tested by asking to copy a figure, draw the face of a clock, cancel symbols on a paper, etc. An individual with hemineglect is only able to copy the part of the image or cancel symbols on the perceived side.
- Common types:
- Motor neglect
- Sensory or perceptual neglect
Insight and judgment
Insight is an individual's awareness and understanding of their current medical problem, and it can be assessed based on the following:
- Recognition that one has a current medical condition
- Compliance with treatment
- Ability to relabel unusual mental events as pathological
- Anosognosia is the inability of a person to recognize their neurologic impairment. 
- The ability of an individual to make considerate decisions when performing a task based on their understanding of the current circumstances and their problem-solving abilities; a higher cortical function
- Primarily elicited when taking the patient's history by discussing recent behaviors. Judgment can also be assessed by asking the patient to elaborate on a hypothetical situation. or interpret a well-known idiom.
- Impaired judgment is not specific and can occur in a number of psychiatric and neurological conditions (e.g., delirium, substance-related disorders, dementia).