DID physiological evidence studies

Birnbaum MH, Thomann K. Visual function in multiple personality disorder. J Am Optom Assoc. 1996 Jun;67(6):327-34 "BACKGROUND: Multiple personality disorder (MPD) is characterized by the existence of two or more personality states that recurrently exchange control over the behavior of the individual. Numerous reports indicate physiological differences, including significant differences in ocular and visual function, across alter personality states in MPD. METHODS: The existing literature was reviewed to provide an overview of the nature and characteristics of MPD, with emphasis on reported physiologic and ocular differences across alter personalities. In addition, a case is reported of an MPD patient seen over a 3-year period. RESULTS: Physiologic differences across alter personality states in MPD include differences in dominant handedness, response to the same medication, allergic sensitivities, autonomic and endocrine function, EEG, VEP, and regional cerebral blood flow. Differences in visual function include variability in visual acuity, refraction, oculomotor status, visual field, color vision, corneal curvature, pupil size, and intraocular pressure in the various personality states of MPD subjects as compared to single personality controls. CONCLUSIONS: The possibility of MPDs should be considered in patients who demonstrate unusual variability in ocular and visual findings, particularly with a positive psychiatric history. The existence of visual and other physiologic differences across alter personalities in MPD offers a unique potential for the study of mind-body relationships." http://www.ncbi.nlm.nih.gov/pubmed/8888853

Miller SD. Optical differences in cases of multiple personality disorder. J Nerv Ment Dis. 1989 Aug;177(8):480-6 "MPD subjects had significantly more variability in visual functioning across alter personalities than did control subjects." http://www.ncbi.nlm.nih.gov/pubmed/2760599

Miller SD, Blackburn T, Scholes G, White GL, Mamalis N. Optical differences in multiple personality disorder. A second look. J Nerv Ment Dis. 1991 Mar;179(3):132-5. "In the present study, data from 20 patients diagnosed with MPD and 20 control subjects role playing MPD were analyzed for statistical and clinical significance. The findings from the present study appear to confirm results from the earlier study that individuals with MPD experience differences in some aspects of visual functioning between alter personalities. The results further confirm that MPD subjects experience more differences across visual measures than control subjects simulating the disorder." http://www.ncbi.nlm.nih.gov/pubmed/1997659

Putnam FW, Zahn TP, Post RM. Psychiatry Res. 1990 Mar;31(3):251-60.Differential autonomic nervous system activity in multiple personality disorder. "Numerous clinical reports suggest that these alter personality states exhibit distinct physiological differences. We investigated differential autonomic nervous system (ANS) activity across nine subjects with MPD and five controls, who produced "alter" personality states by simulation and by hypnosis or deep relaxation. Eight of the nine MPD subjects consistently manifested physiologically distinct alter personality states." http://www.ncbi.nlm.nih.gov/pubmed/2333357

Miller SD, Triggiano PJ. The psychophysiological investigation of multiple personality disorder: review and update. Am J Clin Hypn. 1992 Jul;35(1):47-61. "psychophysiologic differences reported in the literature include changes in cerebral electrical activity, cerebral blood flow, galvanic skin response, skin temperature, event-related potentials, neuroendocrine profiles, thyroid function, response to medication, perception, visual functioning, visual evoked potentials, and in voice, posture, and motor behavior." http://www.ncbi.nlm.nih.gov/pubmed/1442640

Hughes JR, Kuhlman DT, Fichtner CG, Gruenfeld MJ. Brain mapping in a case of multiple personality. Clin Electroencephalogr. 1990 Oct;21(4):200-9. "Brain maps were recorded on a patient with a multiple personality disorder (10 alternate personalities). Maps were recorded with eyes open and eyes closed during 2 different sessions, 2 months apart. Maps from each alternate personality were compared to those of the basic personality "S", some maps were similar and some were different, especially with eyes open. Findings that were replicated in the second session showed differences from 4 personalities, especially in theta and beta 2 frequencies on the left temporal and right posterior regions." http://www.ncbi.nlm.nih.gov/pubmed/2225470

Coons PM, Bowman ES, Milstein V. Multiple personality disorder. A clinical investigation of 50 cases. J Nerv Ment Dis. 1988 Sep;176(9):519-27. "50 consecutive patients with DSM-III multiple personality disorder were assessed using clinical history, psychiatric interview, neurological examination, electroencephalogram, MMPI, intelligence testing, and a variety of psychiatric rating scales. Results revealed that patients with multiple personality are usually women who present with depression, suicide attempts, repeated amnesic episodes, and a history of childhood trauma, particularly sexual abuse....These data suggest that the etiology of multiple personality is strongly related to childhood trauma rather than to an underlying electrophysiological dysfunction." http://www.ncbi.nlm.nih.gov/pubmed/3418321