What initial investigations should be conducted for a patient suspected of having catatonia?

Initial investigations for a patient suspected of having catatonia should primarily focus on identifying any underlying medical or psychiatric causes, as catatonia is a syndrome rather than a standalone diagnosis. A comprehensive assessment should include a thorough review of psychiatric and medical history, including past treatments and response NICE NG54.

• Physical Health Checks: A detailed physical health check is crucial. This should include assessing body mass index (BMI) and waist circumference NICE NG181. Blood tests should encompass a full blood count, glycosylated haemoglobin (HbA1c), blood lipid profile, liver function tests, renal function tests, and thyroid function NICE NG181. Prolactin levels should be checked, particularly if the patient is on medications that raise prolactin NICE NG181. Where appropriate, drug levels for mood stabilising or anti-epileptic medicines, lithium, and clozapine should be considered NICE NG181. An electrocardiogram (ECG) is also an essential part of the initial physical health assessment NICE NG181.
• Ruling out Reversible Causes: It is important to investigate and rule out reversible causes of cognitive decline, such as delirium, depression, sensory impairment (e.g., sight or hearing loss), or cognitive impairment resulting from medicines associated with increased anticholinergic burden NICE NG97.
• General Mental Health Assessment: The assessment should establish specific areas of need, evaluate all potential psychopathology, and describe the nature, duration, and severity of the presenting mental health problem NICE NG54. This includes reviewing physical health problems and current medication, and considering referrals to other specialists if needed NICE NG54. Information regarding recent changes in behaviour should be gathered from family members, carers, or staff, taking into account the nature, quality, and length of their relationship with the person NICE NG54. The assessment should also consider the person's cultural, ethnic, and religious background, and assess the level of drug or alcohol use NICE NG54. Establishing or reviewing a diagnosis should utilise a classification system such as DSM-5 or ICD-10 NICE NG54.