Don Juanism or Don Juan syndrome is a non-clinical term for the desire, in a man, to have sex with many different female partners.

The name derives from the Don Juan of opera and fiction. The term satyriasis is sometimes used as a synonym for Don Juanism. The term has also been referred to as the male equivalent of nymphomania in women. These terms no longer apply with any accuracy as psychological or legal categories of psychological disorder.

Cryptomnesia occurs when a forgotten memory returns without it being recognized as such by the subject, who believes it is something new and original. It is a memory bias whereby a person may falsely recall generating a thought, an idea, a tune, or a joke, not deliberately engaging in plagiarism but rather experiencing a memory as if it were a new inspiration.

An idée fixe is a preoccupation of mind believed to be firmly resistant to any attempt to modify it, a fixation. The name originates from the French "idée", "idea" and "fixe", "fixed."

Sexual addiction, also known as sex addiction, is a state characterized by [[compulsive]] participation or engagement in [[Human sexual activity|sexual activity]], particularly [[sexual intercourse]], despite negative consequences. Proponents of a [[diagnostic model]] for sexual addiction, as defined here, consider it to be one of several sex-related disorders within an umbrella concept known as [[hypersexual disorder]]. The term "sexual dependence" is also used to refer to people who report being unable to control their [[sexual urges]], behaviors, or thoughts. Related models of pathological sexual behavior include [[hypersexuality]] (nymphomania and satyriasis), [[erotomania]], [[Don Juanism]] (or Don Juanitaism), and [[paraphilia]]-related disorders.

The concept of sexual addiction is contentious. There is considerable debate amongst [[psychiatrists]], psychologists, [[sexologist]]s, and other specialists whether compulsive sexual behavior constitutes an addiction, and therefore its classification and possible diagnosis. , sexual addiction is not a clinical diagnosis in either the [[Diagnostic and Statistical Manual of Mental Disorders|DSM]] or [[International Statistical Classification of Diseases and Related Health Problems|ICD]] medical classifications of diseases and medical disorders. Some argue that applying such concepts to normal behaviors such as sex, can be problematic, and suggest that applying medical models such as addiction to human sexuality can serve to [[Slut-shaming|pathologise normal behavior]] and cause harm

Neuroscientists, pharmacologists, molecular biologists, and other researchers in related fields have identified the [[transcription factor|transcriptional]] and [[epigenetic]] mechanisms of addiction [[pathophysiology]]. Diagnostic models, which use the pharmacological model of addiction (this model associates addiction with drug-related concepts, particularly [[physical dependence]], [[drug withdrawal]], and [[drug tolerance]]), do not currently include diagnostic criteria to identify sexual addictions in a clinical setting. In the brain disease model of addiction, which uses neuropsychological concepts to characterize addictions, sexual addictions are identifiable and well-characterized. In this model, [[addictive drugs]] are characterized as those which are both [[reinforcing]] and [[reward system|rewarding]]. Addictive behaviors (those which can induce a compulsive state) are similarly identified and characterized by their rewarding and reinforcing properties.

In "Sexual Addiction and Compulsivity", authors Taylor and Francis argue that: "Obsessive sexual behavior illness is defined by a continual pattern of failure to control intense, repetitive sexual impulses or urges."

People with HPD are usually high-functioning, both socially and professionally. They usually have good social skills, despite tending to use them to manipulate others into making them the center of attention. HPD may also affect a person's social and/or romantic relationships, as well as their ability to cope with losses or failures. They may seek treatment for clinical depression when romantic (or other close personal) relationships end.

Individuals with HPD often fail to see their own personal situation realistically, instead dramatizing and exaggerating their difficulties. They may go through frequent job changes, as they become easily bored and may prefer withdrawing from frustration (instead of facing it). Because they tend to crave novelty and excitement, they may place themselves in risky situations. All of these factors may lead to greater risk of developing clinical depression.

Additional characteristics may include:

- Exhibitionist behavior

- Constant seeking of reassurance or approval

- Excessive sensitivity to criticism or disapproval

- Pride of own personality and unwillingness to change, viewing any change as a threat

- Inappropriately seductive appearance or behavior of a sexual nature

- Using somatic symptoms (of physical illness) to garner attention

- A need to be the center of attention

- Low tolerance for frustration or delayed gratification

- Rapidly shifting emotional states that may appear superficial or exaggerated to others

- Tendency to believe that relationships are more intimate than they actually are

- Making rash decisions

- Blaming personal failures or disappointments on others

- Being easily influenced by others, especially those who treat them approvingly

- Being overly dramatic and emotional

Some people with histrionic traits or personality disorder change their seduction technique into a more maternal or paternal style as they age.

A mnemonic that can be used to remember the characteristics of histrionic personality disorder is shortened as "PRAISE ME":

- Provocative (or seductive) behavior

- Relationships are considered more intimate than they actually are

- Attention-seeking

- Influenced easily by others or circumstances

- Speech (style) wants to impress; lacks detail

- Emotional lability; shallowness

- Make-up; physical appearance is used to draw attention to self

- Exaggerated emotions; theatrical

None of the official diagnostic classification frameworks list "sexual addiction" as a distinct disorder.

Hypersexuality is known to present itself as a symptom in connection to a number of mental and neurological disorders. Some people with borderline personality disorder (sometimes referred to as BPD) can be markedly impulsive, seductive, and extremely sexual. Sexual promiscuity, sexual obsessions, and hypersexuality are very common symptoms for both men and women with BPD. On occasion for some there can be extreme forms of paraphilic drives and desires. "Borderline" patients, due in the opinion of some to the use of splitting, experience love and sexuality in unstable ways.

People with bipolar disorder may often display tremendous swings in sex drive depending on their mood. As defined in the DSM-IV-TR, hypersexuality can be a symptom of hypomania or mania in bipolar disorder or schizoaffective disorder. Pick's disease causes damage to the temporal/frontal lobe of the brain; people with Pick's disease show a range of socially inappropriate behaviors.

Several neurological conditions such as Alzheimer's disease, autism, various types of brain injury, Klüver–Bucy syndrome, Kleine–Levin syndrome, and many more neurodegenerative diseases can cause hypersexual behavior. Sexually inappropriate behavior has been shown to occur in 7-8% of Alzheimer's patients living at home, at a care facility or in a hospital setting. Hypersexuality has also been reported to result as a side-effect of some medications used to treat Parkinson's disease. Some street drugs, such as methamphetamine, may also contribute to hypersexual behavior.

A positive link between the severity of dementia and occurrence of inappropriate behavior has also been found. Hypersexuality can be caused by dementia in a number of ways, including disinhibition due to organic disease, misreading of social cues, understimulation, the persistence of learned sexual behaviour after other behaviours have been lost, and the side-effects of the drugs used to treat dementia. Other possible causes of dementia-related hypersexuality include an inappropriately expressed psychological need for intimacy and forgetfulness of the recent past. As this illness progresses, increasing hypersexuality has been theorized to sometimes compensate for declining self-esteem and cognitive function.

There is little consensus among experts as to the causes of hypersexuality. Some research suggests that some cases can be linked to biochemical or physiological changes that accompany dementia. Psychological needs also complicate the biological explanation, which identifies the temporal/frontal lobe of the brain as the area for regulating libido. Persons suffering from injuries to this part of the brain are at increased risk for aggressive behavior and other behavioral problems including personality changes and socially inappropriate sexual behavior such as hypersexuality. The same symptom can occur after unilateral temporal lobotomy. There are other biological factors that are associated with hypersexuality such as premenstrual changes, and the exposure to virilising hormones in childhood or in utero.

In research involving use of anti-androgens to reduce undesirable sexual behaviour such as hypersexuality, testosterone has been found to be necessary, but not sufficient, for sexual drive. Other proposed factors include a lack of physical closeness, and forgetfulness of the recent past.

Pathogenic overactivity of the dopaminergic mesolimbic pathway in the brain—forming either psychiatrically, during mania, or pharmacologically, as a side effect of dopamine agonists, specifically D-preferring agonists—is associated with various addictions and has been shown to result among some in overindulgent, sometimes hypersexual, behavior.

Psychiatrist Carl Jung believed that Don Juanism was an unconscious desire of a man to seek his mother in every woman he encountered. However, he didn't see the trait as entirely negative; Jung felt that positive aspects of Don Juanism included heroism, perseverance and strength of will.

Jung argues that related to the mother-complex "are homosexuality and Don Juanism, and sometimes also impotence. In homosexuality, the son's entire heterosexuality is tied to the mother in an unconscious form; in Don Juanism, he unconsciously seeks his mother in every woman he meets...Because of the difference in sex, a son's mother-complex does not appear in pure form. This is the reason why in every masculine mother-complex, side by side with the mother archetype, a significant role is played by the image of the man's sexual counterpart, the anima."

One of Theodore Millon's five narcissist variations is the amorous narcissist which includes histrionic features. According to Millon, the Don Juan or Casanova of our times is erotic and exhibitionistic.

Afro-textured hair is the natural hair texture of certain populations in Africa, the African diaspora, Australia and Asia, which has not been altered by hot combs, flat irons or chemicals (through perming, relaxation or other straightening methods). Each strand of this hair type grows in a tiny, spring-like helix shape. The overall effect is such that, compared to straight, wavy or curly hair, afro-textured hair appears denser.

The first documented instance of cryptomnesia occurred in 1874 with the medium Stainton Moses.

The word was first used by the psychiatrist Théodore Flournoy, in reference to the case of medium Hélène Smith (Catherine-Élise Müller) to suggest the high incidence in psychism of "latent memories on the part of the medium that come out, sometimes greatly disfigured by a subliminal work of imagination or reasoning, as so often happens in our ordinary dreams."

Carl Gustav Jung treated the subject in his thesis "On the Psychology and Pathology of So-Called Occult Phenomena" (1902) and in an article, "Cryptomnesia" (1905), suggested the phenomenon in Friedrich Nietzsche's "Thus Spoke Zarathustra". The idea was studied or mentioned by Géza Dukes, Sándor Ferenczi and Wilhelm Stekel as well as by Sigmund Freud in speaking of the originality of his inventions.

As an everyday term, "idée fixe" may indicate a mindset akin to prejudice or stereotyping:

However, "idée fixe" has also a pathological dimension, denoting serious psychological issues, as in this account of Japanese culture for a popular audience:

The pathology is what is denoted in psychology and in the law, as in this technical article about anorexia nervosa:

"Idée fixe" began as a parent category of obsession, and as a preoccupation of mind the "idée fixe" resembles today's obsessive-compulsive disorder: although the afflicted person can think, reason and act like other people, they are unable to stop a particular train of thought or action. However, in obsessive-compulsive disorder, the victim recognizes the absurdity of the obsession or compulsion, not necessarily the case with an "idée fixe", which normally is a delusion. Today, the term "idée fixe" does not denote a specific disorder in psychology, and does not appear as a technical designation in the "Diagnostic and statistical manual of mental disorders". Nonetheless, "idée fixe" is used still as a descriptive term, and appears in dictionaries of psychology.

In many post-Columbian, Western societies, adjectives such as "wooly", "kinky", "nappy", or "spiralled" have frequently been used to describe natural afro-textured hair. More recently, however, it has become common in some circles to apply numerical grading systems to human hair types.

One popular version of these systems classifies afro-textured hair as 'type 4' (straight hair is type 1, wavy type 2, and curly is type 3, with the letters A, B, and C used to indicate the degree of coil variation within each type), with the subcategory of type 4C being most exemplary of this hair type (Walker, 1997). However, afro-textured hair is often difficult to categorize because of the many different variations among individuals. Those variations include pattern (mainly tight coils), pattern size (watch spring to chalk), density (sparse to dense), strand diameter (fine, medium, coarse), and feel (cottony, wooly, spongy).

The chart below is the most commonly used chart to help determine hair types:

Concussions and other types of repetitive play-related head blows in American football have been shown to be the cause of chronic traumatic encephalopathy (CTE), which has led to player suicides and other debilitating symptoms after retirement, including memory loss, depression, anxiety, headaches, and also sleep disturbances.

The list of ex-NFL players that have either been diagnosed "post-mortem" with CTE or have reported symptoms of CTE continues to grow.

Bletting is a process of softening that certain fleshy fruits undergo, beyond ripening. There are some fruits that are either sweeter after some bletting, such as sea buckthorn, or for which most varieties can be eaten raw only after bletting, such as medlars, persimmons, quince, service tree fruit, and wild service tree fruit ("chequers"). The rowan or mountain ash fruit must be bletted and cooked to be edible, to break down the toxic parasorbic acid (hexenollactone) into sorbic acid.

Chemically speaking, bletting brings about an increase in sugars and a decrease in the acids and tannins that cause the unripe fruit to be astringent.

Ripe medlars, for example, are taken from the tree, placed somewhere cool, and allowed to ripen for several weeks. In "Trees and Shrubs", horticulturist F. A. Bush wrote about medlars that "if the fruit is wanted it should be left on the tree until late October and stored until it appears in the first stages of decay; then it is ready for eating. More often the fruit is used for making jelly." Ideally, the fruit should be harvested from the tree immediately following a hard frost, which starts the bletting process by breaking down cell walls and speeding softening.

Once the process is complete, the medlar flesh will have broken down enough that it can be spooned out of the skin. The taste of the sticky, mushy substance has been compared to sweet dates and dry applesauce, with a hint of cinnamon. In "Notes on a Cellar-Book", the great English oenophile George Saintsbury called bletted medlars the "ideal fruit to accompany wine."

In humans, there are two principal types of albinism: oculocutaneous, affecting the eyes, skin and hair, and ocular affecting the eyes only.

There are different types of oculocutaneous albinism depending on which gene has undergone mutation. With some there is no pigment at all. The other end of the spectrum of albinism is "a form of albinism called rufous oculocutaneous albinism, which usually affects dark-skinned people".

According to the National Organization for Albinism and Hypopigmentation, "With ocular albinism, the color of the iris of the eye may vary from blue to green or even brown, and sometimes darkens with age. However, when an eye doctor examines the eye by shining a light from the side of the eye, the light shines back through the iris since very little pigment is present."

Because individuals with albinism have skin that entirely lacks the dark pigment melanin, which helps protect the skin from the sun's ultraviolet radiation, their skin can burn more easily from overexposure.

The human eye normally produces enough pigment to color the iris blue, green or brown and lend opacity to the eye. In photographs, those with albinism are more likely to demonstrate "red eye", due to the red of retina being visible through the iris. Lack of pigment in the eyes also results in problems with vision, both related and unrelated to photosensitivity.

Those afflicted with albinism are generally as healthy as the rest of the population (but see related disorders below), with growth and development occurring as normal, and albinism by itself does not cause mortality, although the lack of pigment blocking ultraviolet radiation increases the risk of melanomas (skin cancers) and other problems.

Development of the optical system is highly dependent on the presence of melanin. For this reason, the reduction or absence of this pigment in people with albinism may lead to:

- Misrouting of the retinogeniculate projections, resulting in abnormal decussation (crossing) of optic nerve fibres

- Photophobia and decreased visual acuity due to light scattering within the eye (ocular straylight) Photophobia is specifically when light enters the eye, unrestricted—with full force. It is painful and causes extreme sensitivity to light.

- Reduced visual acuity due to foveal hypoplasia and possibly light-induced retinal damage.

Eye conditions common in albinism include:

- Nystagmus, irregular rapid movement of the eyes back and forth, or in circular motion.

- Amblyopia, decrease in acuity of one or both eyes due to poor transmission to the brain, often due to other conditions such as strabismus.

- Optic nerve hypoplasia, underdevelopment of the optic nerve.

The improper development of the retinal pigment epithelium (RPE), which in normal eyes absorbs most of the reflected sunlight, further increases glare due to light scattering within the eye. The resulting sensitivity (photophobia) generally leads to discomfort in bright light, but this can be reduced by the use of sunglasses or brimmed hats.

Symptoms of CTE, which occur in four stages, generally appear 8 to 10 years after an athlete experiences repetitive mild traumatic brain injury.

First-stage symptoms include attention deficit hyperactivity disorder as well as confusion, disorientation, dizziness, and headaches. Second-stage symptoms include memory loss, social instability, impulsive behavior, and poor judgment. Third and fourth stages include progressive dementia, movement disorders, hypomimia, speech impediments, sensory processing disorder, tremors, vertigo, deafness, depression and suicidality.

Additional symptoms include dysarthria, dysphagia, cognitive disorder such as amnesia, and ocular abnormalities, such as ptosis.

The condition manifests as dementia, or declining mental ability, problems with memory, dizzy spells or lack of balance to the point of not being able to walk under one's own power for a short time and/or Parkinsonism, or tremors and lack of coordination. It can also cause speech problems and an unsteady gait. Patients with DP may be prone to inappropriate or explosive behavior and may display pathological jealousy or paranoia.

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease found in people who have had multiple head injuries. Symptoms may include behavioral problems, mood problems, and problems with thinking. This typically does not begin until years after the injuries. It often gets worse over time and can result in dementia. It is unclear if the risk of suicide is altered.

Most documented cases have occurred in athletes involved in contact sports such as football, wrestling, ice hockey, and soccer. Other risk factors include being in the military, prior domestic violence, and repeated banging of the head. The exact amount of trauma required for the condition to occur is unknown. Definitive diagnosis can only occur at autopsy. It is a form of tauopathy.

As of 2017 there is no specific treatment. Rates of disease have been found to be about 30% among those with a history of multiple head injuries. Population rates, however, are unclear. Research into brain damage as a result of repeated head injuries began in the 1920s, at which time the condition was known as "punch drunk". Changing the rules in some sports has been discussed as a means of prevention.

Concussions are proven to cause loss of brain function. This can lead to physical and emotional symptoms such as attention disorders, depression, headaches, nausea, and amnesia. These symptoms can last for days or week and even after the symptoms have gone, the brain still won't be completely normal. Players with multiple concussions can have drastically worsened symptoms and exponentially increased recovery time.

Researchers at UCLA have, for the first time, used a brain-imaging tool to identify a certain protein found in five retired NFL players. The presence and accumulation of tau proteins found in the five living players, are associated with Alzheimer's disease. Previously, this type of exam could only be performed with an autopsy. Scientists at UCLA created a chemical marker that binds to the abnormal proteins and they are able to view this with Positron Emission Tomography (PET) scan. Researcher at UCLA, Gary Small explains, "Providing a non-invasive method for early detection is a critical first step in developing interventions to prevent symptom onset and progression in CTE".

Wolfram syndrome, also called DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness), is a rare autosomal-recessive genetic disorder that causes childhood-onset diabetes mellitus, optic atrophy, and deafness as well as various other possible disorders.

It was first described in four siblings in 1938 by Dr. Don J. Wolfram, M.D. The disease affects the central nervous system (especially the brainstem).

The first symptom is typically diabetes mellitus, which is usually diagnosed around the age of 6. The next symptom to appear is often optic atrophy, the wasting of optic nerves, around the age of 11. The first signs of this are loss of colour vision and peripheral vision. The condition worsens over time, and people with optic atrophy are usually blind within 8 years of the first symptoms. Life expectancy of people suffering from this syndrome is about 30 years.

The common symptoms include:

- hyper-pigmentation of the skin

- visual disturbances

- headaches

- abnormal high levels of beta-MSH and ACTH

- abnormal enlargements of the pituitary gland,

- interruption of menstrual cycles in women