Libido
Sigmund Freud, who is considered the originator of the modern use of the term,[8] 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'.
"[9] It is the instinctual energy or force, contained in what Freud called the id, the strictly unconscious structure of the psyche.
From the genetic point of view it is bodily needs like hunger, thirst, sleep, and sex, and emotional states or affects, which constitute the essence of libido.
These symbols may manifest as "fantasy-images" in the process of psychoanalysis, giving subjective expression to the contents of the libido, which otherwise lacks any definite form.
[19] Desire, conceived generally as a psychic longing, movement, displacement and structuring, manifests itself in definable forms which are apprehended through analysis.
[22] Reduced sex drive may also be present in trauma victims due to issues arising in sexual function.
[24] In addition, those with depression often are reluctant to report their reduced sex drive, often normalizing it with cultural/social values, or by the failure of the physician to inquire about it.
[25] Libido is governed primarily by activity in the mesolimbic dopamine pathway (ventral tegmental area and nucleus accumbens).
[27][better source needed] 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 get a boost as a result of the thickening of the uterine lining which stimulates nerve endings and makes a woman feel aroused.
Although some specialists disagree with this theory, menopause is still considered by the majority a factor that can cause decreased sexual desire in women.
[47] Moreover, specialists suggest that several lifestyle changes such as exercising, quitting smoking, lowering consumption of alcohol or using prescription drugs may help increase one's sexual desire.
On the other hand, a reduced libido is also often iatrogenic and can be caused by many medications, such as hormonal contraception, SSRIs and other antidepressants, antipsychotics, opioids, beta blockers and isotretinoin.
Isotretinoin, finasteride and many SSRIs uncommonly can cause a long-term decrease in libido and overall sexual function, sometimes lasting for months or years after users of these drugs have stopped taking them.
Multiple studies have shown that with the exception of bupropion (Wellbutrin), trazodone (Desyrel) and nefazodone (Serzone), antidepressants generally will lead to lowered libido.
[24] SSRIs that typically lead to decreased libido are fluoxetine (Prozac), paroxetine (Paxil), fluvoxamine (Luvox), citalopram (Celexa) and sertraline (Zoloft).
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.
[57][58] The surge in testosterone hits the male at puberty resulting in a sudden and extreme sex drive which reaches its peak at age 15–16, then drops slowly over their lifetime.
[61] Older adults generally develop a reduced libido due to declining health and environmental or social factors.
[62] Women often report family responsibilities, health, relationship problems, and well-being as inhibitors to their sexual desires.
[65] Erectile dysfunction may happen to the penis because of lack of sexual desire, but these two should not be confused since the two can commonly occur simultaneously.
[67] Although conversely, excessive or very regular/repeated high-dose amphetamine use may damage leydig cells in the male testes, potentially leading to markedly lowered sexual desire subsequently due to hypogonadism.
However, in contrast to this, other stimulants such as cocaine and even caffeine appear to lack negative impacts on testosterone levels, and may even increase their concentrations in the body.
