The association of lower urinary tract symptoms with schizophrenia and its treatments: A narrative review

Background A higher incidence of lower urinary tract symptoms (LUTS) in people with schizophrenia compared to the general population is often suggested. However, it is not clear whether this is a genuine association, and whether it is a direct result of schizophrenia itself, or a side‐effect of certain antipsychotics. Methods We undertook a narrative review evaluating how the published literature reports the relationship between LUTS and schizophrenia and its treatments. We searched Embase, Ovid Emcare, and Ovid MEDLINE(R) ALL to August 2022, limited to the English language. We selected the following search terms: schizophrenia, schizophrenic, LUTS, overactive bladder, urinary urgency, urinary incontinence, overactive bladder, enuresis, nocturnal enuresis, and voiding dysregulation. We identified seven domains for assessment in advance of commencing the review. These were the categorization, description, and treatment status of schizophrenia; evaluation of LUTS; categorization of LUTS confounders; recapturing of the disease states of both schizophrenia and LUTS after therapies; assessment of the association between LUTS and schizophrenia and/or antipsychotics. Results The association between LUTS and schizophrenia was poorly described. The evidence was low quality and focused predominantly on urinary incontinence as an antipsychotic side effect, neglecting other LUTS. The status of schizophrenia was often incompletely characterized, and no papers made use of a bladder diary or LUTS‐specific questionnaires to assess symptoms. No papers collected information about LUTS in patients not on antipsychotics, nor did any thoroughly evaluate the influence of confounding variables. Despite the tendency of symptoms and severity of both conditions to fluctuate over time, no studies fully assessed the status of both schizophrenia and LUTS at baseline, therapy initiation, and follow‐up. Conclusions It is not possible to state whether there is an association between LUTS and schizophrenia or its treatments. This review highlights the need to improve research and clinical management of the urinary tract in schizophrenia, with meticulously designed longitudinal studies.