Underlying disorder

For much of the 20^th Century, it was thought that catatonia was a hallmark of schizophrenia. It is now recognised that catatonia can feature in a large range of disorders. It is critical to identify the underlying cause, so that appropriate treatment can be directed. In many cases, there is an underlying mental illness, but in around 20%, there is an organic cause. (Oldham, 2018)

Common psychiatric causes

Depression
Psychosis
Mania
Autism
Tourette’s
Obsessive compulsive disorder (OCD)
Severe anxiety

Some organic causes

Central nervous system (CNS) structural lesions
CNS infections (especially Herpes simplex virus encephalitis and neurosyphilis)
Autoimmune encephalitis (especially N-methyl-D-aspartate (NMDA) receptor encephalitis)
Systemic lupus erythematosus (SLE)
Multiple sclerosis
Thyroid disease
Seizures
Medication use, including recreational drugs (especially tacrolimus, ciclosporin, MDMA, corticosteroids, fluoroquinolones, disulfiram, antipsychotics, phencyclidine)
Medication withdrawal (especially benzodiazepines and clozapine)