Different types of childhood abuse can increase the risk of mental illness as well as sexual dysfunction, experts say, but the biological mechanism by which this occurs has been unknown.

New research may provide an answer with the discovery that sexually abused and emotionally mistreated children exhibit specific and differential changes in the architecture of their brain.

In the study, an international team of researchers discovered that brain changes reflect the nature of the mistreatment.

Researchers have known that victims of childhood abuse often suffer from psychiatric disorders later in life, including sexual dysfunction following sexual abuse.

The underlying mechanisms facilitating this association have been poorly understood.

Charles B. Nemeroff, M.D., Ph.D. and a group of scientists hypothesized that brain or cortical changes during segments of mistreatment played a role.

Investigators used magnetic resonance imaging (MRI) to examine the brains of 51 adult women who were exposed to various forms of childhood abuse.

The results showed a correlation between specific forms of maltreatment and thinning of the cortex in precisely the regions of the brain that are involved in the perception or processing of the type of abuse.

Specifically, the somatosensory cortex in the area in which the female genitals are represented was significantly thinner in women who were victims of sexual abuse in their childhood.

Similarly, victims of emotional mistreatment were found to have a reduction of the thickness of the cerebral cortex in specific areas associated with self-awareness, self-evaluation and emotional regulation.

“This is one of the first studies documenting long-term alterations in specific brain areas as a consequence of child abuse and neglect,” said Nemeroff.

“The finding that specific types of early life trauma have discrete, long lasting effects on the brain that underlie symptoms in adults is an important step in developing novel therapies to intervene to reduce the often lifelong psychiatric/psychological burden of such trauma.”

The scientists speculate that a regional thinning of the cortex may serve as a protective mechanism, immediately shielding the child from the experience of the abuse by gating or blocking the sensory experience.

However, that thinning of the cortical sections may lay the groundwork for the development of behavioral problems in adulthood.

Experts say this study expands knowledge on neural plasticity and shows that cortical representation fields can be smaller when certain sensory experiences are damaged or developed inappropriate.

Source: University of Miami