A number of investigators presented reports of series of schizophrenic patients whose symptoms were reportedly improved with hemodialysis (American Psychiatric Association, 1979; Malek-Ahmdi et al, 1980). Subsequent, well-designed, sham-controlled clinical trials, however, have found that hemodialysis had no significant effect on schizophrenia symptoms (Vanherweghern et al, 1979; Diaz-Buxo et al, 1980; Schulz and Van Kammen, 1981; Carpenter et al, 1983; Schulman et al, 1983; Vanherweghern et al, 1983; van Kammen et al, 1983; Wagemaker et al, 1983; Wagemaker et al, 1984; Schulman, 1985).

A Medicare National Coverage Determination states: "Scientific evidence supporting use of hemodialysis as a safe and effective means of treatment for schizophrenia is inconclusive at this time. Accordingly, Medicare does not cover hemodialysis for treatment of schizophrenia".

Cox and colleagues (2020) noted that increasing evidence suggested that circulating factors and immune dysfunction may contribute to the pathogenesis of schizophrenia. In particular, pro-inflammatory cytokines, complement and autoantibodies against central nervous system (CNS) epitopes have recently been associated with psychosis. Related concepts in previous decades led to several clinical trials of dialysis and plasmapheresis as treatments for schizophrenia. These trials may have relevance for the current understanding of schizophrenia. These researchers examined if dialysis or plasmapheresis are beneficial interventions in schizophrenia. They carried out a systematic search in major electronic databases for high-quality studies (randomized, double-blinded trials with sham controls) applying either hemodialysis or plasmapheresis as an intervention in patients with schizophrenia, published in English from the start of records until September 2018. These investigators found 9 studies meeting inclusion criteria, reporting on a total of 105 patients who received either sham or active intervention; 1 out of 8 studies reported a beneficial effect of hemodialysis on schizophrenia, 1 a detrimental effect and 6 no effect. The 1 trial of plasmapheresis found it to be ineffective. Adverse events (AEs) were reported in 23 % of patients. Studies were at unclear or high risk of bias. The authors concluded that it is unlikely that hemodialysis is a beneficial treatment in schizophrenia, although the studies were of small size and could not consider potential subgroups. Plasmapheresis was only addressed by 1 study and warrants further exploration as a treatment modality in schizophrenia.

Scope of Policy

This Clinical Policy Bulletin addresses hemodialysis for schizophrenia.

Experimental and Investigational

Hemodialysis for the treatment of schizophrenia is considered experimental and investigational because the effectiveness of this approach has not been demonstrated and established.