Classification & Assessment in Psychiatry · Paper A
Catatonia
Recognising catatoniaA syndrome of abnormal movement and behaviour, ranging from being frozen and unresponsive to being excessively agitated.Read more → matters because it connects a striking disturbance of movement and responsiveness to a fast, specific treatment most other psychiatric presentations do not have. It is a psychomotorRelating to the link between mental state and physical movement, such as being visibly slowed down or agitated.Read more → syndrome (one where the link between thought and movement breaks down). The patient may be in a stuporA state of reduced responsiveness and near-total lack of movement or speech, while remaining conscious.Read more → (awake but unresponsive), mute and immobile, hold odd fixed postures, show waxy flexibilityA catatonic sign where a limb, moved into a position by someone else, stays there as if made of soft wax.Read more → (limbs stay where you place them, like bending a soft candle), or resist or copy everything the examiner does. Take a rigid, mute patient given a trial dose of a benzodiazepine who begins moving and speaking within minutes: that rapid response both confirms the diagnosis and starts treatment.
CatatoniaA syndrome of abnormal movement and behaviour, ranging from being frozen and unresponsive to being excessively agitated.Read more → is now recognised across mood disorders, psychotic disorders and general medical illness, not only in schizophreniaA long-term mental illness involving episodes of psychosis such as hallucinations and delusions.Read more → (a chronic psychotic illness). Severity is rated with tools such as the Bush-Francis scale. First-line treatment is a benzodiazepine (a calming sedative); the 'lorazepam challenge' is both a diagnostic test and a treatment. ECTElectroconvulsive therapy, a treatment that uses a brief controlled seizure to relieve severe depression.Read more → (electroconvulsive therapy, a brief, controlled therapeutic seizure given under anaesthetic) is the next step when benzodiazepines fail or the case is severe. High-potencyHow small a dose of a drug is needed to produce a given effect.Read more → antipsychotics are generally avoided (e.g. haloperidol given for a mute, rigid patient can precipitate malignant catatonia instead of resolving it). Kahlbaum coined the term catatonia in the nineteenth century. MutismA complete absence of speech despite the physical ability to speak.Read more →, alongside stuporA state of reduced responsiveness and near-total lack of movement or speech, while remaining conscious.Read more → and posturing, is among the most frequently observed catatonic signs in psychiatric inpatient case series.
Psychiatry usually treats mood, thought and behaviour as connected: what you feel shapes what you do. is the dramatic exception: a syndrome (a disorder of movement and behaviour, not of mood or thought content directly) in which that connection seems to break. A person can be fully conscious yet immobile, or able to move yet unable to initiate speech. Recognising catatonia matters because it is treatable, often within hours, using medication that has nothing to do with a standard antipsychotic or antidepressant.
is a cluster of abnormal movements and behaviours that occur together: (a state of being awake but not responding), (not speaking), immobility, rigid or odd fixed postures, (cerea flexibilitas: a limb stays wherever the examiner places it, like bending a soft candle), (resisting or refusing instructions for no apparent reason), and echo phenomena such as (repeating what is said to you) or (copying what is done in front of you). Some patients show the opposite pattern instead: excited catatonia, with purposeless agitation and excessive movement rather than stillness.
The biggest mistake is assuming only occurs in . Historically it was described as a subtype of schizophrenia, but it is now recognised across mood disorders (severe depression and ), other psychotic disorders, and general medical illness, and can occur with no psychiatric diagnosis at all. The second trap: treating catatonic rigidity with a higher dose of an antipsychotic, on the assumption the patient is simply more psychotic. High- antipsychotics can worsen catatonia and precipitate malignant catatonia, a life-threatening escalation.
Imagine the brain's motor system as having both a "go" signal and a "stop" signal that normally balance out to produce smooth, purposeful movement. In , that balance is disrupted: patients are thought to have abnormal (gamma-aminobutyric acid, the brain's main calming ) signalling, which is why benzodiazepines (drugs that boost GABA activity) so reliably help. This is why catatonia behaves differently from ordinary psychosis: it is not primarily a dopamine problem, so dopamine-blocking antipsychotics do not fix it and can make it worse.
Picture a 34-year-old woman brought to hospital mute, lying rigidly in bed, eyes open, not responding to questions. When the doctor lifts her arm, it stays exactly where placed, an example of . She is given a test dose of 2mg lorazepam intravenously (the "lorazepam challenge") and within 10 to 15 minutes she begins moving her limbs and answering simple questions. That rapid response to a single dose is itself diagnostic: it confirms and simultaneously starts effective treatment, one intervention doing both jobs at once.
Catatonic can resemble severe depression with retardation, but depression does not produce or echo phenomena. malignant syndrome (NMS, a dangerous drug reaction to antipsychotics) can mimic catatonic rigidity, but NMS follows starting or raising an antipsychotic dose and features fever and autonomic instability from the outset, whereas can arise without any drug trigger and typically lacks fever until it becomes malignant. Locked-in syndrome (a rare brainstem stroke leaving only eye movement intact) can look superficially similar but has a clear neurological cause and no waxy flexibility.
There is no blood test for ; diagnosis rests on recognising the clinical pattern. The Bush-Francis Catatonia Rating Scale is the standard structured tool: it screens for a defined list of signs (immobility, , staring, posturing, , , echophenomena and others), and a threshold number of positive signs supports the diagnosis. The lorazepam challenge test doubles as a diagnostic criterion: a clear, even partial, response to a benzodiazepine strongly supports the diagnosis. Underlying causes (autoimmune encephalitis, metabolic derangement, substance intoxication or withdrawal) should be actively screened for, since catatonia is often a final common pathway rather than a stand-alone illness.
First-line treatment is a benzodiazepine, usually lorazepam, titrated upward until the resolves: this is explicitly recommended in the Maudsley Prescribing Guidelines in Psychiatry, the standard UK psychiatric prescribing reference. If benzodiazepines fail, or the catatonia is severe or malignant, electroconvulsive therapy (ECT: a brief, controlled therapeutic seizure delivered under general anaesthetic) is the next step and is highly effective, endorsed by Royal College of Psychiatrists guidance on ECT use. High- antipsychotics are avoided until catatonia has resolved, because of the risk of worsening it into malignant catatonia (fever, autonomic instability and severe rigidity, closely resembling ). Supportive care, hydration, prevention of pressure sores and blood clots (venous thromboembolism) from prolonged immobility, runs alongside specific treatment throughout.
If a vignette describes an immobile, mute patient who improves within minutes of a benzodiazepine injection, the diagnosis is and the answer they want is "benzodiazepine" (usually lorazepam), not "increase the antipsychotic." A vignette describing catatonia worsening after an antipsychotic dose increase, with new fever, is testing malignant catatonia or .
is a treatable movement-and-responsiveness syndrome, seen across many underlying illnesses, confirmed by response to a benzodiazepine and escalated to if that fails, never treated by raising an antipsychotic.