Conundrums in a theory of disturbed dreaming: comment on Levin and Nielsen (2007).

Levin and Nielsen (2007) presented a review of research emphasizing dreams whose content is distressing. With some broad conclusions about factors important in the understanding of distressing dreams as a springboard, the authors offered potential explanatory mechanisms for distressing dreams that range from brain structures to personality variables, drawing heavily on findings about posttraumatic stress disorder. Though a reasonable case is made for elements of the argument, implications from one perspective are not always considered in making the argument for others, issues that follow logically from certain assertions are not discussed, and certain assumptions appear unjustified. Definitional or phenomenological presentations are not always consistent, making it difficult to determine the real nature of the variables being offered and to get a clear sense of the boundaries of the model.