The Mental State Examination

Introduction

The mental state examination (MSE) is a structured description of a patient's psychological functioning at the time of the interview. It is the psychiatric counterpart of the physical examination: the history tells you what has happened over time, while the MSE records what you observe and elicit right now.¹

The distinction matters and is a common source of error. 'Has felt low for three months' belongs in the history. 'Appeared tearful, described mood as 2 out of 10' belongs in the MSE. Students frequently blur the two, which loses marks in OSCEs and, more importantly, makes the record less useful, because the value of a serially recorded MSE lies in tracking change from one assessment to the next.

The MSE is also not confined to psychiatry. It is used in emergency medicine, geriatrics, general practice and on medical wards - anywhere a patient's mental state is relevant to their care, which is almost everywhere.² A competently recorded MSE communicates the clinical picture to the next clinician far more effectively than an impression such as 'seems depressed'.

Appearance and behaviour

Observation begins the moment you see the patient, including how they were in the waiting area and how they respond to being called. Describe objectively and specifically.

Appearance

• General - apparent age relative to stated age, build, ethnicity if relevant to the record
• Self-care and clothing - clean or unkempt, appropriate to the weather and setting, bizarre or flamboyant dress (which may suggest mania), multiple layers in warm weather
• Physical signs - self-harm scars or fresh wounds, injection sites, tremor, jaundice, tar staining, dehydration, evidence of weight loss
• Objects brought - extensive documents and files (sometimes seen in querulous or persecutory presentations), bags containing possessions suggesting homelessness

Behaviour

• Eye contact - appropriate, reduced, avoidant, or intense and staring
• Rapport - established easily, or guarded, suspicious, hostile or overfamiliar
• Psychomotor activity - retardation (slowed movement and responses, seen in severe depression), agitation (restlessness, pacing, hand-wringing), or normal
• Abnormal movements - tremor, tics, akathisia (a subjective inner restlessness with an inability to stay still, a common and distressing antipsychotic side effect), tardive dyskinesia (involuntary orofacial movements), dystonia
• Catatonic features - stupor, mutism, waxy flexibility (limbs remain in positions in which they are placed), negativism (resistance to instruction), echopraxia (imitating the examiner's movements)
• Response to unseen stimuli - appearing to listen to or talk to something not present, glancing at a corner of the room, which suggests hallucinations

Speech

Describe the mechanics of speech here - what the patient says belongs under thought content, not speech. A useful framework is rate, rhythm, volume and quantity.

• Rate - normal, slow (depression, hypothyroidism), or rapid
• Volume - normal, quiet (depression), loud (mania, intoxication, deafness)
• Quantity - normal, poverty of speech (alogia, seen in depression and in negative symptoms of schizophrenia), or excessive
• Pressure of speech - rapid, increased in amount, and difficult or impossible to interrupt - characteristic of mania
• Tone and prosody - normal, monotonous, or with abnormal rhythm
• Latency of response - the delay before answering, which is prolonged in depression and psychomotor retardation
• Fluency and articulation - dysarthria (intoxication, neurological), dysphasia (which points to a neurological cause and should not be mistaken for thought disorder), stammer
• Neologisms - invented words, or ordinary words used with idiosyncratic meaning

Mood and affect

These are distinct and frequently confused, and knowing the difference reliably earns marks.

Describing affect

• Reactive - normal variation in response to the content of conversation
• Blunted - markedly reduced intensity of emotional expression
• Flat - virtually no emotional expression at all
• Labile - rapid, marked and sometimes abrupt shifts in emotional expression
• Incongruent - emotional expression that does not match the content, such as laughing while describing a bereavement - seen in schizophrenia
• Restricted - a narrowed but not absent range

Also record anhedonia (loss of pleasure), anxiety, and diurnal variation if reported. This is a natural place to ask about biological symptoms of depression - sleep, appetite, weight, energy, libido and concentration - though the detail of these may sit in the history depending on local convention.

Thought

Thought is divided into form (how thoughts are organised and connected) and content (what the thoughts are about). Keeping these separate is one of the clearest markers of a well-structured MSE.

Thought form

• Circumstantiality - excessive, over-inclusive detail, but the point is eventually reached
• Tangentiality - drifting away from the point and never returning to it
• Flight of ideas - rapid movement between topics with discernible connections between them, often via puns or clang associations (linking by sound rather than meaning) - characteristic of mania
• Loosening of association (derailment) - shifts between topics with no discernible logical connection, the listener losing the thread - characteristic of schizophrenia
• Thought block - an abrupt cessation of the flow of thought mid-sentence, with the thought lost entirely
• Perseveration - persistent repetition of a word or idea beyond the point of relevance, often with an organic cause
• Word salad - completely incoherent, disorganised speech, in severe thought disorder
• Neologisms - newly invented words

Thought content

• Delusions - fixed, false beliefs held with complete conviction, unshakeable by contrary evidence and out of keeping with the person's culture. Specify the type: persecutory, grandiose, nihilistic (belief that one is dead or does not exist), guilt, hypochondriacal, delusions of reference (that unrelated events refer specifically to the patient), or delusional perception (a normal perception given intense private meaning).
• Thought alienation - thought insertion, withdrawal or broadcast; a first-rank symptom of schizophrenia
• Passivity phenomena - the belief that actions, feelings or impulses are controlled externally
• Obsessions - recurrent, intrusive, unwanted thoughts recognised as one's own and resisted (contrast with delusions and thought insertion)
• Overvalued ideas - strongly held beliefs that are not fully delusional and are, in principle, understandable given the person's background
• Preoccupations and ruminations - repetitive dwelling on a theme, common in depression and anxiety
• Suicidal and homicidal ideation - always asked about directly and explicitly, with intent, plan and means

Perception

Ask openly - 'Have you seen or heard anything that others could not?' - and then characterise anything reported in detail.

• Hallucination - a perception occurring in the absence of any external stimulus, experienced as real and originating in external space. Specify the modality: auditory (commonest in schizophrenia - note whether second person, addressing the patient, or third person, discussing them), visual (raises suspicion of an organic cause, delirium or substance use), olfactory or gustatory (consider temporal lobe epilepsy), tactile (formication - sensation of insects crawling, seen in stimulant use and delirium tremens)
• Illusion - a misperception of a real external stimulus, such as mistaking a coat on a door for a person. Illusions occur in healthy people, particularly in poor lighting or when anxious, and are much less significant than hallucinations.
• Pseudohallucination - experienced as arising in internal subjective space and recognised as not real, for example a voice heard 'inside my head' that the person knows is not external
• Hypnagogic and hypnopompic hallucinations - occurring when falling asleep and on waking respectively; both are normal phenomena and not pathological
• Depersonalisation - a sense of being detached from oneself, or that one is unreal
• Derealisation - a sense that the surroundings are unreal, dreamlike or two-dimensional

Cognition

The depth of cognitive assessment should match the clinical question - a brief screen in a young person with anxiety, a formal tool in an older adult with possible dementia or in anyone with suspected delirium.

• Level of consciousness - alert, drowsy, fluctuating. Any impairment or fluctuation strongly suggests delirium rather than a primary psychiatric disorder.
• Orientation - to time, place and person
• Attention and concentration - serial sevens, or reciting the months of the year backwards, which is quicker and less education-dependent
• Memory - registration and recall of three items after a delay; short-term and long-term memory in conversation
• Language - naming, repetition, comprehension
• Executive function - verbal fluency, abstract reasoning, proverb interpretation
• Formal tools - AMT or 4AT for a rapid screen (the 4AT is specifically designed for delirium), MoCA or ACE-III where dementia is suspected. The MMSE is still encountered but is less sensitive to mild impairment and to frontal and executive dysfunction.

Insight

Insight is frequently recorded as simply 'good' or 'poor', which wastes the opportunity. It is better described as a set of separable components, because these can and do dissociate - a patient may accept they are unwell but reject the proposed treatment, or accept medication while denying they are ill.

1. Does the patient recognise that something is wrong or different?
2. Do they accept that this represents a mental health problem, rather than attributing it to a physical or external cause?
3. Do they accept the specific diagnosis or explanation offered?
4. Do they agree that treatment is needed, and are they willing to accept it?

Record it descriptively: 'Accepts that he has not been sleeping and that his family are worried, but firmly rejects that the voices are a symptom of illness, attributing them to neighbours. Willing to take medication for sleep but not an antipsychotic.' That is far more clinically useful, and directly relevant to decisions about the Mental Health Act, than 'insight poor'.

Risk assessment

Strictly, risk assessment sits alongside rather than within the MSE, but it must never be omitted, and in an OSCE, failing to mention it is a common reason for failing the station.³

• Risk to self - suicidal ideation, intent, plan, access to means, protective factors, and self-harm
• Risk to others - thoughts of harming others, any specific person identified, particularly where driven by delusional belief or command hallucinations
• Risk from others - exploitation, abuse, domestic violence, and vulnerability arising from the mental state itself
• Self-neglect - eating and drinking, medication adherence, personal care, housing and finances
• Risk to dependants - children or vulnerable adults in the person's care; consider safeguarding explicitly
• Other risks - driving, absconding from hospital, firearms access, and reputational or financial harm from disinhibited behaviour

Presenting the MSE

Present in a consistent order, using descriptive language and direct quotation where a phrase captures something well. A worked example:

'On examination, Mr A was a 34-year-old man who appeared older than his stated age. He was unkempt, wearing several layers of clothing despite the warm weather, with poor personal hygiene. He made minimal eye contact and appeared guarded, repeatedly glancing towards the door. There was no psychomotor agitation or retardation.

Speech was quiet and slow, with prolonged latency of response, but was normal in tone and articulation. He described his mood as 'flat, empty' and objectively his affect was blunted and restricted in range, though congruent with the content of his speech.

Thought form showed occasional loosening of association, with two occasions on which I was unable to follow the connection between successive statements. In terms of content, he expressed a persecutory delusion that his neighbours were monitoring him through the electrical wiring, held with complete conviction. He denied thought insertion, withdrawal or broadcast. He described third-person auditory hallucinations of two male voices discussing his actions, present daily for several months, without command content. There was no evidence of visual hallucination.

He was alert and fully orientated, with no evidence of cognitive impairment on brief testing. He recognises that he has become withdrawn and that his sleep is poor, but does not accept that the voices or the beliefs about his neighbours represent illness, and is reluctant to consider antipsychotic medication.

On risk assessment, he denied any thoughts of self-harm or suicide, and denied any intent to harm his neighbours, though he described feeling angry towards them. He is eating poorly and has lost weight. There are no dependants.'

Summary

The MSE is a systematic, descriptive record of a patient's mental state at one moment in time, structured through appearance and behaviour, speech, mood and affect, thought form and content, perception, cognition and insight, with risk assessment alongside. Its value lies in precision and in repeatability: a well-recorded MSE lets the next clinician see what you saw, and lets both of you detect change.

The skill is descriptive discipline - recording what was observed and said rather than what it was assumed to mean. Interpretation and diagnosis belong in the formulation that follows. Master the terminology, keep the domains distinct, always include the relevant negatives, and never leave out risk.