The International Journal of Neuropsychopharmacology

Research Article

The relationship between childhood abuse and dissociation. Is it influenced by catechol-O-methyltransferase (COMT) activity?

Jonathan B. Savitza1 c1, Lize van der Merwea2, Timothy K. Newmana3, Mark Solmsa4, Dan J. Steina3 and Rajkumar S. Ramesara1

a1 MRC/UCT Human Genetics Research Unit, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa

a2 Biostatistics Unit, Medical Research Council of South Africa, Tygerberg, South Africa

a3 Department of Psychiatry, University of Cape Town, South Africa

a4 Departments of Psychology and Neurology, University of Cape Town, South Africa

Abstract

Dissociation is a failure of perceptual, memorial and emotional integration that is associated with a variety of psychiatric disorders. Dissociative processes are usually attributed to the sequelae of childhood trauma although there are data to suggest that genetic influences are also important. Bipolar disorder (BD), a condition with a strong genetic basis, has also been associated with early psychological trauma. Since childhood trauma is a risk factor for both BD and dissociation, we tested for potential gene–childhood abuse interactions on dissociation in a pilot sample of BD probands and their affected and unaffected relatives (n=178). Dissociation was measured with the Dissociative Experiences Scale (DES II) and childhood maltreatment with the Childhood Trauma Questionnaire (CTQ). The BD and recurrent unipolar depression (MDE-R) groups showed higher levels of self-reported abuse and dissociation than their unaffected relatives. The low-activity Met allele of the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene was associated with lower levels of self-reported dissociation. Further, the functional catechol-O-methyltransferase (COMT) Val158Met polymorphism interacted significantly with total CTQ abuse scores to impact perceived dissociation. The Val/Val genotype was associated with increasing levels of dissociation in participants exposed to higher levels of childhood trauma. The opposite was observed in people with Met/Met genotypes who displayed decreased dissociation with increasing self-reported childhood trauma. The current findings support the involvement of the COMT Val158Met polymorphism in mediating the relationship between trauma and psychopathology.

(Received January 22 2007)

(Reviewed April 16 2007)

(Revised May 14 2007)

(Accepted May 28 2007)

(Online publication July 03 2007)

Correspondence:

c1 Correspondence: Dr J. B. Savitz, MRC/UCT Human Genetics Research Unit, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa. Tel.: 301 594 1427 Fax: 301 594 1427 E-mail: savitzj@mail.nih.gov

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