Libido and Desire

September 15, 2011

Few people can forget the impassioned romance between Julie Christie (Lara) and Omar Sharif (Yuri) in the film Doctor Zhivago, the palpable sexual tension between Kathleen Turner and William Hurt in Body Heat, or the fervent desire expressed by Meg Ryan while faking an orgasm in When Harry Met Sally. Anais Nin’s (1990) erotic stories in Delta of Venus and D. H. Lawrence’s (1968) Lady Chatterley’s Lover explore other aspects of women’s libido and desire. We remember these stories and films because we identify and resonate with the various components of the characters’ sexuality, sometimes stimulating our own desire. The concept of desire has expanded considerably since Freud (1963/1923) introduced “libido”: the biologic, instinct-based sexual force driving human growth and development. Now by desire we also mean to include the psychologically based motive and the socially based wish (Levine, 1992).

Biologic drive is individually determined and fluctuates over the lifespan. Freud noted sexual feelings and behaviors in children that heighten, expand, and become more focused during puberty and adolescence, eventually becoming a motivating force for adult behavior. The complex neurobiological changes of puberty, commonly referred to as “raging hormones,” stimulate sex drive. This hormonal fluctuation tends to stabilize in young adulthood. A man’s sex drive tends to remain higher than a woman’s. Women may note variability in their drive with the different stages of the menstrual cycle. The reproductive years and pregnancy pose biologic challenges to women that influence drive significantly. With advancing age, sexual drive usually declines in both sexes and is partially attributed to the gradual lowering of testosterone levels.

The literature on the neurobiology of sex drive which is reviewed by Meston and Frohlich (2000) and summarized here, focuses on the hypothalamic region of the brain which is thought to be the sexual drive center. It is a complex group of nerve cells with connections to the limbic system and the cerebral cortex. The limbic system is crucial to emotional experience and regulation; the cortex is vital to cognitive and thinking processes. These neuroanatomic connections suggest that sexual drive is a product of these brain regions operationalized through a delicate balance of neurotransmitters. These neurotransmitters include dopamine, serotonin, histamine, norepinephrine, and epinephrine, which can be influenced by many medications and street drugs. Drive tends to increase with higher levels of dopamine and lower levels of histamine. Epinephrine and norepinephrine appear to stimulate motivation but have little effect on drive itself. The effect of serotonin on drive and motivation is complicated due to its multiple roles in brain function via stimulation of receptors. Stimulation of some receptors results in the improvement of biologically based depressive symptoms, which increases sexual drive. Stimulation of other receptors directly impairs both sexual drive and function. This has become especially apparent with the increased use of antidepressant medication in the selective serotonin reuptake inhibitor category (e.g., fluoxetine [Prozac], sertraline [Zoloft], paroxetine [Paxil]) and others. Frequently, these medications will raise serotonin levels and stimulate both types of receptors. This simultaneously results in the improvement in a person’s depression or anxiety such that they once again would like to have sex but impairs their intrinsic drive and other sexual functions. Different antidepressants stimulate dopamine and enhance drive or have no effect (e.g., bupropion, Wellbutrin). Not infrequently, elderly patients with low levels of dopamine due to Parkinson’s disease or high prolactin levels (see below) have no sex drive, but will become much more sexual when dopamine-stimulating drugs are given.

Hormones, particularly testosterone and prolactin, significantly influence sexual drive, although hormones alone do not regulate human sexual desire. Testosterone makes a significant contribution to the sexual upheaval of puberty but tends to steady in early adulthood. As a man’s sex drive is highly testosterone dependent, supplementation may restore his drive when drive and testosterone levels are low. Although testosterone supplementation in women with low desire and low testosterone levels may increase drive, it is not usually done because of the risk of masculinization (Meston & Frohlich, 2000). Due to controversy in the field, women considering testosterone, DHEA (a testosterone precursor), or other chemical replacements for low desire should first consult medical personnel knowledgeable in sexual medicine. High levels of prolactin appear to inhibit sex drive in both sexes. In women, a prolactin blood level high enough to decrease drive is caused by pregnancy, antipsychotic medication, prolactin-secreting pituitary tumors, and, more commonly, by lactation and breast-feeding. Prolactin has an inverse relationship with dopamine, such that increased levels of dopamine in the brain may lower prolactin levels and increase drive. Estrogen and progesterone are believed to have little direct influence on sex drive (Meston & Frohlich, 2000). Nonetheless, drying and increased fragility of the vaginal lining due to estrogen decline and deficiency causes discomfort that interferes with desire. Estrogen levels decline with aging or with early menopause due to medical factors (e.g., chemotherapy). The resulting vaginal symptoms can be ameliorated with lubricants or, if warranted, with hormone replacement therapies. However, estrogen replacement therapy can further suppress an already low testosterone resulting in a further decline in drive.

Biologic drive establishes “horniness,” a base for the development of the arousing, emotional richness of real sexual life as portrayed in the films and books above. The richness is created by the more potent elements of desire: motive and wish. Levine (1992) describes motive as the psychological aspect of sexual desire and is a person’s emotional willingness to act sexually. The wish includes the social factors that influence and form personal expectations about sex. how does the person’s religion, philosophy, finances, degree of socialization, education, national or territorial origin, culture, employment, and political point of view influence sexual desire? The most successful books and movies examine the complexities of both motive and wish in the context of their storytelling. In Doctor Zhivago, Lara’s and Yuri’s passionate concordance of personalities, as if they were predestined to be together, fosters mutually intense desire. The pressures of the social environment created by the war heightened the desire, despite the social taboo of adultery. Turner’s dark motives for seduction in Body Heat meshed perfectly with Hurt’s mesmeric infatuation, blinding him to the realities of his situation. Sally’s and Harry’s inability to endorse their mutual attraction, and their hurtful interactions were clear de-motivators of desire. In Lady Chatterley’s Lover, Constance Chatterley’s affair with the gamekeeper on her husband’s estate was motivated by unfulfilled emotional and sexual longings in her sterile marriage. Today this book is a classic but at the time it was written, it was scorned as pornography and labeled as offensive to society. Anais Nin’s frank erotica speaks to women’s ability to acknowledge, experience, and enjoy their sexuality and particularly their lusty desires. To this day, she is seen as a licentious, sexual outlaw by social and political conservatives. Defiantly challenging social taboos is a powerful aphrodisiac for the sexually adventurous.

Despite the almost daily discoveries in neuroscience, we should not underestimate the power of the nonscientific qualities determining a woman’s sexual desire. When a woman’s biologic drive, motive, and wish are consonant, her sexuality is a remarkable manifestation of her essence.

SEE ALSO: Masturbation, Sexual dysfunction

Suggested Reading

  • Freud, S. (1963/1923). The libido theory. In P. Rieff (Ed.), General psychological theory: Papers on metapsychology (pp. 180—184). New York: Colliers Books.
  • Lawrence, D. H. (1968). Lady Chatterley’s lover (The Unexpurgated 1928 Orioli Edition). New York: Bantam Books.
  • Levine, S. B. (1992). Sexual life: A clinician’s guide. New York: Plenum Press.
  • Meston, C. M., & Frohlich, P. F. (2000). The neurobiology of sexual function. Archives of General Psychiatry, 57, 1012—1030.
  • Nin, A. (1990). Delta of Venus. New York: Pocket Books.

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