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https://doi.org/10.1016/j.eclinm.2019.01.013 2589-5370/© 2019 Published by Elsevier Ltd. T In this issue of EClinicalMedicine, Rollins and colleagues [1] report the illness itself, including delusions, thought disorder, or cognitive deficits. Any neuroanatomical differences between them and healthy conthat hallucinations in psychiatric and neurological patients have neuroanatomically distinct signatures. This conclusion followed a careful and systematic meta-analysis and review of the existing structural neuro-anatomical literature on hallucinations, across sensory modalities and diagnoses. We emphasize “existing” to underscore that fact that Rollins and colleagues are constrained by what has already appeared in the literature: By necessity, most of the papers in their analysis involve primarily auditory hallucinations in psychiatric patients (for example, schizophrenia), and mostly visual hallucinations in neurological patients (for example, Parkinson's and Alzheimer's Disease). As the field becomes increasingly aware that voices are experienced by other diagnostic groups [2], more papers should be appearing soon that include neuro-structural correlates of hallucinations in these patients, as well. But, for now, the literature is limited. Similarly, although non-clinical populations can also experience hallucinations, there is only one study of neuroanatomical correlates of hallucinations in healthy people, as Rollins et al. point out. This is an important growth area for the field: If the voices healthy young adults experience were the same as those experienced by neurological and psychiatric patients, we could study their neural basis without the confounds of aging, cognitive decline, and functional deterioration. To this point, Rollins et al. argue for more neuroimaging and cognitive research in non-clinical groups. Rollins and colleagues required that studies included in their analysis compared patients who experienced hallucinations to patients who did not. Studies that compare patients who hear voices to healthy controls pose a tough interpretative problem: Are the effects reported due to the diagnosis or specifically to the presence of hallucinations? Rollins