Classification & Assessment in Psychiatry · Paper A
Catatonic phenomena
CatatoniaA syndrome of abnormal movement and behaviour, ranging from being frozen and unresponsive to being excessively agitated.Read more → matters clinically because naming a motor sign as catatonic, rather than treating it as ordinary psychosis or depression, decides whether the next step is a benzodiazepine or an antipsychotic that could harm the patient. It is a psychomotorRelating to the link between mental state and physical movement, such as being visibly slowed down or agitated.Read more → (movement-and-behaviour) syndrome that can occur in mood, psychotic, organic or autistic conditions, and it is recognised by a specific set of named signs rather than by the underlying diagnosis. A patient who holds an arm exactly where you place it, as though it were made of wax, is showing waxy flexibilityA catatonic sign where a limb, moved into a position by someone else, stays there as if made of soft wax.Read more →, and naming that sign is the first step to recognising catatonia, whatever caused it.
Waxy flexibilityA catatonic sign where a limb, moved into a position by someone else, stays there as if made of soft wax.Read more → (flexibilitas cerea) is when limbs are moulded into a position and held there like wax. Mitgehen is excessive cooperation, where light pressure moves the limb fully despite an instruction to resist, the 'anglepoise' sign. NegativismResisting or doing the opposite of what is asked, without any apparent reason.Read more → is motiveless resistance to all instructions, the opposite of mitgehen. Posturing is voluntarily assuming and holding a bizarre posture, and ambitendency is a hesitant alternation between cooperating and resisting. EchopraxiaAutomatically imitating another person's movements or gestures.Read more → (copying movements) and echolaliaAutomatically repeating another person's spoken words.Read more → (repeating speech) also occur. Gently trying to move a patient's arm while asking them to resist illustrates the differences directly: full cooperation despite the 'resist me' instruction is mitgehen, active resistance is negativism, and slow wax-like yielding is waxy flexibility. That single bedside manoeuvre distinguishes several of these signs from each other.
A fresh doctor might assume a rigid, mute, unresponsive patient is simply severely psychotic or deeply sedated, and manage them the same way. That assumption is dangerous: is a distinct syndrome (movement-and-behaviour syndrome) that crosses mood, psychotic, organic, and autistic conditions, and it responds fast to a specific, different first-line treatment. Hold the phrase NAMED SIGN through every section below, because catatonia is recognised by identifying specific signs, not by guessing the underlying diagnosis first.
is a syndrome (a cluster of features, not one disease) marked by abnormalities of movement, behaviour, and responsiveness that can occur alongside mood disorders, psychotic disorders, autism, and general medical or organic conditions. It is diagnosed by recognising a set of named clinical signs at the bedside, commonly screened for and rated using the Bush-Francis Catatonia Rating Scale.
A common mistake is treating a stuporose, unresponsive patient as simply psychotic and escalating an antipsychotic dose. Antipsychotics, particularly high- ones, can precipitate malignant , a severe form with autonomic instability and hyperthermia that closely resembles malignant syndrome (). Recognising catatonia as a specific syndrome, rather than assuming it is only a symptom of the underlying psychotic illness, is the single most safety-critical judgement in this topic.
is defined by its motor and behavioural PATTERN, not by its cause: the same set of signs can appear in severe depression, , , autism, or encephalitis. That is exactly why the correct clinical habit is to spot the signs first and treat the catatonia itself, rather than trying to guess the underlying diagnosis before acting; the underlying cause is worked out afterward, once the acutely dangerous state is stabilised.
is a state of marked hypoactivity where the patient is awake but essentially unresponsive to their surroundings. Mutism is an absence of speech despite an apparently intact ability to speak. is motiveless resistance to instructions or attempts to move the patient: asked to open their eyes, the patient may resist entirely. (flexibilitas cerea) describes limbs that can be moulded into a position by an examiner and remain held there, as though made of wax. Posturing is voluntarily assuming and maintaining an unusual or uncomfortable posture for a prolonged period.
is the automatic, parrot-like repetition of another person's speech, while is the automatic imitation of another person's movements. Automatic obedience is an exaggerated, unquestioning compliance with simple instructions, sometimes to an absurd degree. For example, a patient who copies an examiner tapping their own nose without being asked to, purely because they were shown the movement, is displaying echopraxia. These imitative signs sit at the opposite end of the spectrum from , illustrating that can present with either resistance or excessive compliance.
Because can arise from many different underlying causes, screening with a structured tool such as the Bush-Francis Catatonia Rating Scale helps standardise recognition and severity rating across different presentations, whether the underlying condition is depression, , , autism, or a general medical illness such as encephalitis. A careful physical and neurological assessment alongside this screening helps exclude an organic cause needing separate treatment.
malignant syndrome () is the most important and most tested look-alike: both present with rigidity, autonomic instability, and reduced responsiveness, but NMS specifically follows recent antipsychotic exposure or dose increase and typically shows a markedly elevated creatine kinase and lead-pipe rigidity, whereas can occur without any antipsychotic trigger at all: and, confusingly, malignant catatonia and NMS can be very difficult to tell apart at the bedside, which is one reason antipsychotics are avoided until catatonia is excluded or treated. Locked-in syndrome (caused by a brainstem lesion, typically a pontine stroke) can mimic catatonic because the patient appears unresponsive, but the patient is fully conscious and aware, and can communicate through vertical eye movements or blinking: a critical distinction, since missing it means missing a conscious, communicating patient. Severe retardation in depression can look similar to catatonic stupor from a distance, but lacks the specific bedside signs such as , , or echophenomena that define catatonia proper.
is diagnosed clinically, by eliciting and counting named signs at the bedside using a structured instrument such as the Bush-Francis Catatonia Rating Scale, rather than by any blood test or scan: imaging and bloods are used instead to look for an underlying organic cause (such as encephalitis) once catatonia itself has been recognised. A positive response to a benzodiazepine challenge, described below, is also used as a supportive diagnostic step, since a clear improvement strongly supports the diagnosis.
First-line management of is a benzodiazepine, typically given as a lorazepam challenge: a trial dose that is both diagnostic (a clear improvement supports the diagnosis) and therapeutic. If catatonia is refractory to benzodiazepines, or is severe or malignant, ECT (electroconvulsive therapy, a brief controlled therapeutic seizure given under anaesthetic) is the next step and can be lifesaving. Antipsychotics are generally avoided or used with extreme caution during active catatonia because of the risk of precipitating malignant catatonia; once catatonia has resolved, the underlying psychiatric disorder can then be treated more conventionally.
Vignettes often describe a mute, immobile patient whose antipsychotic dose is increased, after which the patient deteriorates further with fever and rigidity: this is testing recognition of antipsychotic-precipitated malignant , not confirmation that a higher dose was needed. Another common trap asks candidates to distinguish (slow, wax-like yielding to an imposed position) from (active resistance to being moved), which are frequently swapped as distractors.
is a syndrome recognised by named signs (, , , , posturing, , , and automatic obedience) screened for with the Bush-Francis Catatonia Rating Scale; first-line treatment is a lorazepam challenge, with reserved for refractory or malignant catatonia, and antipsychotics avoided during active catatonic episodes because they can precipitate a malignant, -like form.