https://www.selleckchem.com/products/lurbinectedin.html suggests that up to 50% of the population served by fluoridated water systems may not receive its full caries-preventive benefits due to not consuming plain tap water. Our findings add support for the need to identify and address barriers to tap water consumption and promote health benefits of fluoridation. Half of US youth consumed plain tap water on a given day. Consuming plain tap water was not associated with community water fluoridation status. This finding suggests that up to 50% of the population served by fluoridated water systems may not receive its full caries-preventive benefits due to not consuming plain tap water. Our findings add support for the need to identify and address barriers to tap water consumption and promote health benefits of fluoridation. Psoriatic Arthritis (PsA) is a multifaceted disease in which various musculoskeletal and skin manifestations are involved. Beyond these features, PsA is associated with comorbidities that might increase the burden of the disease. In the last years a growing interest has come out for the concept of multimorbidity in rheumatology. Multimorbidity was defined as the 'co-existence of two or more chronic diseases in the same individual.' In the multimorbidity concept, the patient is of central concern and all coexisting diseases are of equal importance. Comorbidity was defined as the 'occurrence of any distinct additional entity during the clinical course of patient who has the index disease under study.' In PsA, comorbidity and multimorbidity have often been confusingly used interchangeably, showing that there is an unmet need on this topic. This perspective article dealt with these different visions of the co-existence of other diseases in PsA, providing a distinction between them, not only for the impact on the treatment decision but also in how this concept might be incorporated into clinical trials design, choosing the right outcome measures for the p