Insight in True Charles Bonnet Syndrome

To the Editor: In a recent issue of your journal, Gupta et al. 1 described two patients who are said to suffer from true Charles Bonnet syndrome. 1 Although there is no universal consensus about the diagnostic criteria of Charles Bonnet syndrome, the prefix “true” suggests the most stringent criteria and, in particular, the presence of full insight into the hallucinatory nature of the images together with the absence of cognitive decline. 2 Interestingly, many patients seem to pass through an initial phase of deception before recognizing the unreality of these images. 3 However, the 60-year-old man reported by Gupta and colleagues has a 6-year history of abnormal behavior (washing his hands, trying to get rid of the bugs on his food and clothes) directly related to the lack of insight in the hallucinatory nature of the bugs he sees. Therefore I suggest not to use the term “true Charles Bonnet syndrome,” and maybe not even the term Charles Bonnet syndrome for his condition, especially since Charles Bonnet himself stressed in his original description of the syndrome the fact that the patient was healthy and had a normal judgment and memory. 4 It would be more adequate to use the descriptive term “complex visual hallucinations” rather than an eponym.