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Libido //, and colloquially sex drive, is a person's overall sexual drive or desire for sexual activity. Sex drive is determined by biological, psychological, and social factors. Biologically, levels of hormones such as testosterone are believed to affect sex drive; social factors, such as work and family, also have an impact; as do internal psychological factors, like personality and stress. Sex drive may be affected by medical conditions, medications, lifestyle and relationship issues. A person who has extremely frequent or a suddenly increased sex drive may be experiencing hypersexuality, or puberty in which the body builds up chemicals and causes a higher sex drive. Asexual people may lack any sexual desires.
A person may have a desire for sex, but not have the opportunity to act on that desire, or may on personal, moral or religious reasons refrain from acting on the urge. Psychologically, a person's urge can be repressed or sublimated. On the other hand, a person can engage in sexual activity without an actual desire for it. Multiple factors affect human sex drive, including stress, illness, pregnancy, and others.
Sexual desires are often an important factor in the formation and maintenance of intimate relationships in both men and women, and a lack or loss of sexual desire can adversely affect relationships. Changes in the sexual desires of either partner in a sexual relationship, if sustained and unresolved, may cause problems in the relationship. The infidelity of a partner may be an indication that a partner's changing sexual desires can no longer be satisfied within the current relationship. Problems can arise from disparity of sexual desires between partners, or poor communication between partners of sexual needs and preferences.
Sigmund Freud defined libido as "the energy, regarded as a quantitative magnitude ... of those instincts which have to do with all that may be comprised under the word 'love'." It is the instinct energy or force, contained in what Freud called the id, the strictly unconscious structure of the psyche.
Freud developed the idea of a series of developmental phases in which the libido fixates on different erogenous zones—first in the oral stage (exemplified by an infant's pleasure in nursing), then in the anal stage (exemplified by a toddler's pleasure in controlling his or her bowels), then in the phallic stage, through a latency stage in which the libido is dormant, to its reemergence at puberty in the genital stage. (Karl Abraham would later add subdivisions in both oral and anal stages). Freud pointed out that these libidinal drives can conflict with the conventions of civilized behavior, represented in the psyche by the superego. It is this need to conform to society and control the libido that leads to tension and disturbance in the individual, prompting the use of ego defenses to dissipate the psychic energy of these unmet and mostly unconscious needs into other forms. Excessive use of ego defenses results in neurosis. A primary goal of psychoanalysis is to bring the drives of the id into consciousness, allowing them to be met directly and thus reducing the patient's reliance on ego defenses.
Freud viewed libido as passing through a series of developmental stages within the individual. Failure to adequately adapt to the demands of these different stages could result in libidinal energy becoming 'dammed up' or fixated in these stages, producing certain pathological character traits in adulthood. Thus the psychopathologized individual for Freud was an immature individual, and the goal of psychoanalysis was to bring these fixations to conscious awareness so that the libido energy would be freed up and available for conscious use in some sort of constructive sublimation.
According to Swiss psychiatrist Carl Gustav Jung, the libido is identified as psychic energy. Duality (opposition) that creates the energy (or libido) of the psyche, which Jung asserts expresses itself only through symbols: "It is the energy that manifests itself in the life process and is perceived subjectively as striving and desire." (Ellenberger, 697)
Psychological factors can reduce the desire for sex. These factors can include lack of privacy or intimacy, stress or fatigue, distraction or depression. Environmental stress, such as prolonged exposure to elevated sound levels or bright light, can also affect libido. Other causes include experience of sexual abuse, assault, trauma, or neglect, body image issues and anxiety about engaging in sexual activity.
Physical factors that can affect libido include: endocrine issues such as hypothyroidism, levels of available testosterone in the bloodstream of both women and men, the effect of certain prescription medications (for example flutamide), various lifestyle factors and the attractiveness and biological fitness of one's partner. Inborn lack of sexual desire, often observed in asexual people, can also be considered a physical factor. In males, the frequency of ejaculations affects the libido. If the gap between ejaculations is long, there will be a stronger desire for sexual activity.
Smoking, alcohol abuse and drug abuse may also cause disruptions in the hormonal balances and therefore lead to a decreased libido. Moreover, specialists suggest that several lifestyle changes such as exercising, quitting smoking, lower consumption of alcohol or using prescription drugs may help increase one's sexual desire. Learning stress management techniques can be helpful for individuals who experience libido impairment due to a stressful life.
Reduced libido is also often iatrogenic and can be caused by many medications, such as hormonal contraception, SSRIs and other antidepressants, antipsychotics, opioids and beta blockers. In some cases iatrogenic impotence or other sexual dysfunction can be permanent, as in post-SSRI sexual dysfunction (PSSD).
Testosterone is one of the hormones controlling libido in human beings. Emerging research is showing that hormonal contraception methods like Oral contraceptive pills (which rely on estrogen and progesterone together) are causing low libido in females by elevating levels of sex hormone binding globulin (SHBG). SHBG binds to sex hormones, including testosterone, rendering them unavailable. Research is showing that even after ending a hormonal contraceptive method, SHBG levels remain elevated and no reliable data exists to predict when this phenomenon will diminish.
Males reach the peak of their sex drive in their teens, while females reach it in their thirties. The surge in testosterone hits the male at puberty resulting in a sudden and extreme sex drive which reaches its peak in early adolescence, and then drops slowly over his lifetime. In contrast, a female's libido increases slowly during adolescence and peaks in her mid-thirties. Actual testosterone and estrogen level, which affect a person's sex drive vary considerably.
A woman's desire for sex is correlated to her menstrual cycle, with many women experiencing a heightened sexual desire in the several days immediately before ovulation, which is her peak fertility period, which normally occurs two days before until two days after the ovulation. This cycle has been associated with changes in a woman's testosterone levels during the menstrual cycle. According to Gabrielle Lichterman, testosterone levels have a direct impact on a woman's interest in sex. According to her, testosterone levels rise gradually from about the 24th day of a woman's menstrual cycle until ovulation on about the 14th day of the next cycle, and during this period the woman's desire for sex increases consistently. The 13th day is generally the day with the highest testosterone levels. In the week following ovulation, the testosterone level is the lowest and as a result women will experience less interest in sex.
Also, during the week following ovulation, progesterone levels increase, resulting in a woman experiencing difficulty achieving orgasm. Although the last days of the menstrual cycle are marked by a constant testosterone level, women's libido may boost as a result of the thickening of the uterine lining which stimulates nerve endings and makes a woman feel aroused. Also, during these days, estrogen levels also decline, resulting in a decrease of natural lubrication.
Although some specialists disagree with this theory, menopause is still considered by the majority a factor that can cause decreased sex desire in women. The levels of estrogen decrease at menopause and this usually causes a lower interest in sex and vaginal dryness which makes intercourse painful. However, the levels of testosterone increase at menopause and this is why some women may experience a contrary effect of an increased libido.
There is no widely accepted measure of what is a healthy level for sex desire. Some people want to have sex every day, or more than once a day; others once a year or not at all. However, a person who lacks a desire for sexual activity for some period of time may be experiencing a hypoactive sexual desire disorder or may be asexual. A sexual desire disorder is more common in women than in men. Erectile dysfunction can only occur in men and may be a cause for the lack of sexual desire, however, these two should not be confused. Moreover, specialists have brought to attention that libido impairment may not even occur in cases of men with erectile dysfunction. However, men can also experience a decrease in their libido as they age.
The American Medical Association has estimated that several million US women suffer from a female sexual arousal disorder, though arousal is not at all synonymous with desire, so this finding is of limited relevance to the discussion of libido. Some specialists claim that women may experience low libido due to some hormonal abnormalities such as lack of luteinising hormone or androgenic hormones, although these theories are still controversial. Also, women commonly lack sexual desire in the period immediately after giving birth. Moreover, any condition affecting the genital area can make women reject the idea of having intercourse. It has been estimated that half of women experience different health problems in the area of the vagina and vulva, such as thinning, tightening, dryness or atrophy. Frustration may appear as a result of these issues and because many of them lead to painful sexual intercourse, many women prefer not having sex at all. Surgery or major health conditions such as arthritis, cancer, diabetes, high blood pressure, coronary artery disease or infertility may have the same effect in women. Surgery that affects the hormonal levels in women include oophrectomies.
Libido (sex drive) is modulated primarily by activity in the mesolimbic dopamine pathway (ventral tegmental area and nucleus accumbens). Consequently, dopamine and the trace amines (mainly phenethylamine and tyramine) that regulate dopamine neurotransmission play a critical role in regulating libido.
Other neurotransmitters, neuropeptides, and sex hormones that affect sex drive by modulating activity in or acting upon this pathway include:
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The sex drive evolved to motivate individuals to seek a range of mating partners; attraction evolved to motivate individuals to prefer and pursue specific partners; and attachment evolved to motivate individuals to remain together long enough to complete species-specific parenting duties. These three behavioural repertoires appear to be based on brain systems that are largely distinct yet interrelated, and they interact in specific ways to orchestrate reproduction, using both hormones and monoamines. ... Animal studies indicate that elevated activity of dopaminergic pathways can stimulate a cascade of reactions, including the release of testosterone and oestrogen (Wenkstern et al. 1993; Kawashima &Takagi 1994; Ferrari & Giuliana 1995; Hull et al. 1995, 1997, 2002; Szezypka et al. 1998; Wersinger & Rissman 2000). Likewise, increasing levels of testosterone and oestrogen promote dopamine release ...This positive relationship between elevated activity of central dopamine, elevated sex steroids and elevated sexual arousal and sexual performance (Herbert 1996; Fiorino et al. 1997; Liu et al. 1998; Pfaff 2005) also occurs in humans (Walker et al. 1993; Clayton et al. 2000; Heaton 2000). ... This parental attachment system has been associated with the activity of the neuropeptides, oxytocin (OT) in the nucleus accumbens and arginine vasopressin (AVP) in the ventral pallidum ... The activities of central oxytocin and vasopressin have been associated with both partner preference and attachment behaviours, while dopaminergic pathways have been associated more specifically with partner preference.
Recent studies also highlight remarkable anxiolytic and prosocial effects of intranasally administered OT in humans, including increased ‘trust’, decreased amygdala activation towards fear-inducing stimuli, improved recognition of social cues and increased gaze directed towards the eye regions of others (Kirsch et al., 2005; Kosfeld et al., 2005; Domes et al., 2006; Guastella et al., 2008).