I happened to catch part of a Science Channel show called Secret Life of the Brain: Losing Control, which examined the lives of four people who each had experienced a brain injury resulting in severe obsessive disorders. The extent of the obsession in each case was dramatically life-altering -affecting relationships, careers, and making any sense of homeostasis or normalcy impossible.
In one case, a woman experienced brain trauma resulting in hypersexuality. Once a committed, monogamous wife, she became unable to control her libido and desire to sleep with random men. To paraphrase one of the commentating psychologists on the show, her “braking system to regulate sexual desire and activity was no longer functioning.”
During her interviews, the woman was obviously distraught but equally unable to do anything about her behavior. She confessed that after a random sexual interlude, she experienced regret and remorse about further damaging her marriage, but eventually she did exactly the same thing over and over again.
What intrigues me about this, combined with some subsequent research on the topic, is two things: first, the consistency with which hypersexuality presents as a result of (particularly) temporal lobe injuries. Most of these sexual disorders are not as severe as that of the woman in the Science Channel show, and are often short-lived, but how common they are is surprising to me. This study details five cases of brain-trauma induced hypersexuality, ranging from marginally embarrassing behavior to outright sexual aggression. Here’s an abbreviated version of one of the cases:
A 24-year-old male was admitted to the hospital in coma due to severe head injury following a road accident. He had a Glasgow Coma score of 3 at the time of admission. Ocular examination revealed normal sized pupils, both of which reacted sluggishly to light. His limbs were flaccid and all tendon reflexes were depressed. He remained deeply comatose for seven weeks after which his level of consciousness started to improve gradually. By the end of the tenth week, he had recovered sufficiently to the extent where he could obey verbal commands, but remained aphasic until the twelfth week. At this time, he began to manifest hypersexual behaviour. The latter was first signalled by the strong arousal anytime he was being attended to by female ward staff. This was soon replaced by increasing agitation whenever a female was nearby; and subsequently – when his ability to verbalise returned – his unabashed demand for sex, and finally his attempt to grab a female attendant. Besides minor tranquilizer which was given on account of his agitation, no specific medication was administered to control his altered sexual behaviour. He progressively became less agitated in the presence of female staff and by the end of the second week after onset of hypersexual behaviour, he had completely normalized.
The second thing that intrigues me about this topic is how a heightened understanding of this behavior may further understanding of deviant sexual behavior in general. The linkage between brain injury, or otherwise-induced brain disorder (including, perhaps, genetic) and aberrant, obsessive or aggressive sexual behavior may in fact be very strong – which in turn opens a three-story can of worms on the moral front. I’ll be very interested to see how this plays out.
For those interested, this literature review covers a great deal of ground on the topic, including advances to date and limitations of brain imaging studies on hypersexuality. And here’s a list of 16 known causes of hypersexuality.