Sir: Carey et al (Psychiatric Bulletin, February 2002, 26, 68-70) discussed the clinical issues surrounding a patient with features of catatonia and neuroleptic malignant syndrome (NMS). The relationship between the two conditions has been conceptualised in three ways. Castillo et al (Reference Castillo, Rubin and Holsboer-Trachsler1989) argue that lethal catatonia and NMS can be distinguished by clinical features, especially lead-pipe rigidity. Mann et al (Reference Mann, Caroff and Bleier1986) state that lethal catatonia is a syndrome that may have many causes, one of which is NMS. Bristow and Kohen (Reference Bristow and Kohen1996) regard catatonia as a risk factor for the development of NMS and lethal catatonia being identical to NMS.

The literature is less informative about the longitudinal features of both conditions. NMS recurs in a minority of patients and catatonia can recur. Although there is a consensus on the avoidance of neuroleptics in the acute stages of both conditions, there is little research to guide clinicians on their long-term management. The patient that the authors discussed experienced a relapse while treated with risperidone and lithium and they do not state the follow-up period after the second episode. The re-introduction of neuroleptic treatment after a near fatal episode of NMS or lethal catatonia appears to be associated with a high risk. Prospective data are needed on patients re-challenged with neuroleptics versus those in whom neuroleptics are withheld in order to help establish whether the conditions may be differentiated and to clarify the long-term risks and benefits of neuroleptic treatment.