The American Psychiatric Association permits a diagnosis of "gender dysphoria" if the criteria in the DSM-5 are met. The DSM-5 moved this diagnosis out of the sexual disorders category and into a category of its own. The DSM-5 states that at least two of the criteria for gender dysphoria must be experienced for at least six months' duration in adolescents or adults for diagnosis. The diagnosis was renamed from "Gender Identity Disorder" to "Gender Dysphoria", after criticisms that the former term was stigmatizing. Subtyping by sexual orientation was deleted. The diagnosis for children was separated from that for adults, as "gender dysphoria in children". The creation of a specific diagnosis for children reflects the lesser ability of children to have insight into what they are experiencing, or ability to express it in the event that they have insight.

The International Classification of Diseases (ICD-10) list three diagnostic criteria for "transsexualism" (F64.0): Uncertainty about gender identity which causes anxiety or stress is diagnosed as sexual maturation disorder, according to the ICD-10.

The question of whether to counsel young children to be happy with their assigned sex, or to encourage them to continue to exhibit behaviors that do not match their assigned sex—or to explore a transsexual transition—is controversial. Some clinicians report that a significant proportion of young children diagnosed with gender dysphoria later do not exhibit any dysphoria.

Professionals who treat gender identity disorder in children have begun to refer and prescribe hormones, known as a puberty blocker, to delay the onset of puberty until a child is believed to be old enough to make an informed decision on whether hormonal gender reassignment leading to surgical gender reassignment will be in that person's best interest.

When the WHO removed the diagnosis of homosexuality as a mental disorder in ICD-10, it included the diagnosis of "ego-dystonic sexual orientation" under "Psychological and behavioural disorders associated with sexual development and orientation". The WHO's ICD-10 diagnoses ego-dystonic sexual orientation thus:

The gender identity or sexual preference (heterosexual, homosexual, bisexual, or prepubertal) is not in doubt, but the individual wishes it were different because of associated psychological and behavioural disorders, and may seek treatment in order to change it. ()

The WHO notes that for codes under F66: "Sexual orientation by itself is not to be regarded as a disorder."

Patients are sometimes still diagnosed as having this problem. This is often a result of unfavorable and intolerant attitudes of the society or a conflict between sexual urges and religious belief systems.

Psychosexual disorders can vary greatly in severity and treatability. Medical professionals and licensed therapists are necessary in diagnosis and treatment plans. Treatment can vary from therapy to prescription medication. Sex therapy, behavioral therapy, and group therapy may be helpful to those suffering distress from sexual dysfunction. More serious sexual perversions may be treated with androgen blockers or selective serotonin reuptake inhibitors (SSRIs) to help restore hormonal and neurochemical balances.

In the DSM-5 all paraphilia disorders can be diagnosed by two main criteria that are referred to criteria A and criteria B respectively. The A and B criteria include a duration in which the behavior must be present for (typically 6 months) and specific details of actions or thoughts that are correlated specifically with the respective disorder being diagnosed.

There are many ways a person may go about receiving therapy for ego-dystonic sexual orientation associated with homosexuality. There is no known therapy for other types of ego-dystonic sexual orientations. Therapy can be aimed at changing sexual orientation, sexual behaviour, or helping a client become more comfortable with their sexual orientation and behaviours. Human rights groups have accused some countries of performing these treatments on egosyntonic homosexuals. One survey suggested that viewing the same-sex activities as compulsive facilitated commitment to a mixed-orientation marriage and to monogamy. Treatment may include sexual orientation change efforts or treatment to alleviate the stress. In addition, some people seek non-professional methods, such as religious counselling or attendance in an ex-gay group.

Therapeutic approaches for GIDC differ from those used on adults and have included behavior therapy, psychodynamic therapy, group therapy, and parent counseling. Proponents of this intervention seek to reduce gender dysphoria, make children more comfortable with their bodies, lessen ostracism, and reduce the child's psychiatric comorbidity. The majority of therapists currently employ these techniques. "Two short term goals have been discussed in the literature: the reduction or elimination of social ostracism and conflict, and the alleviation of underlying or associated psychopathology. Longer term goals have focused on the prevention of transsexualism and/or homosexuality."

Individual therapy with the child seeks to identify and resolve underlying factors, including familial factors; encourage identification by sex assigned at birth; and encourage same-sex friendships. Parent counseling involves setting limits on the child's cross-gender behavior; encouraging gender-neutral or sex-typical activities; examining familial factors; and examining parental factors such as psychopathology. Longtime researchers of gender identity disorder, Kenneth Zucker and Susan Bradley, state that it has been found that boys with gender identity disorder often have mothers who to an extent reinforced behavior more stereotypical of young girls. They also note that children with gender identity disorder tend to come from families where cross-gender role behavior was not explicitly discouraged. However, they also acknowledge that one could view these findings as merely indicative of the fact that parents who were more accepting of their child's cross-gender role behavior are also more likely to bring their children to a clinical psychiatrist as opposed to parents who are less accepting of cross-gender role behavior in their children (Bradley, Zucker, 1997). " Proponents acknowledge limited data on GIDC: "apart from a series of intrasubject behaviour therapy case reports from the 1970s, one will find not a single randomized controlled treatment trial in the literature" (Zucker 2001). Psychiatrist Domenico Di Ceglie opines that for therapeutic intervention, "efficacy is unclear," and psychologist Bernadette Wren says, "There is little evidence, however, that any psychological treatments have much effect in changing gender identity although some treatment centres continue to promote this as an aim (e.g. Zucker, & Bradley, 1995)." Zucker has stated that "the therapist must rely on the 'clinical wisdom' that has accumulated and to utilize largely untested case formulation conceptual models to inform treatment approaches and decisions."

In May 2013, the American Psychiatric Association published the DSM-5 in which the GIDC diagnosis was removed and replaced with gender dysphoria, for the first time in its own distinct chapter. Lev states that gender dysphoria places the focus on distress with one's body rather than conformity with societal gender norms, and that this change was accompanied by changes to sexist language and a reduced reliance on binary gender categories. Gender dysphoria reframes the diagnosis as a time-limited distress of the body which is potentially rectified with access to gender transition procedures, rather than a lifetime disorder of the identity.

Most psychologists believe that paraphilic sexual interests cannot be altered. Instead, the goal of therapy is normally to reduce the person's discomfort with their paraphilia and limit any criminal behavior. Both psychotherapeutic and pharmacological methods are available to these ends.

Cognitive behavioral therapy, at times, can help people with paraphilias develop strategies to avoid acting on their interests. Patients are taught to identify and cope with factors that make acting on their interests more likely, such as stress. It is currently the only form of psychotherapy for paraphilias supported by evidence.

Antiandrogens are used in more severe cases. Similar to physical castration, they work by reducing androgen levels, and have thus been described as chemical castration. The antiandrogen cyproterone acetate has been shown to substantially reduce sexual fantasies and offending behaviors. Medroxyprogesterone acetate and gonadotropin-releasing hormone agonists (such as leuprolide acetate) have also been used to lower sex drive. Due to the side effects, the World Federation of Societies of Biological Psychiatry recommends that hormonal treatments only be used when there is a serious risk of sexual violence, or when other methods have failed. Surgical castration has largely been abandoned because these pharmacological alternatives are similarly effective and less invasive.

"Sex reassignment therapy" (SRT) is an umbrella term for all medical treatments related to sex reassignment of both transgender and intersex people.

Individuals make different choices regarding sex reassignment therapy, which may include female-to-male or male-to-female hormone replacement therapy (HRT) to modify secondary sex characteristics, sex reassignment surgery (such as orchiectomy) to alter primary sex characteristics, chest surgery such as top surgery or breast augmentation, or, in the case of trans women, a trachea shave, facial feminization surgery or permanent hair removal.

To obtain sex reassignment therapy, transsexual people are generally required to undergo a psychological evaluation and receive a diagnosis of gender identity disorder in accordance with the Standards of Care (SOC) as published by the World Professional Association for Transgender Health. This assessment is usually accompanied by counseling on issues of adjustment to the desired gender role, effects and risks of medical treatments, and sometimes also by psychological therapy. The SOC are intended as guidelines, not inflexible rules, and are intended to ensure that clients are properly informed and in sound psychological health, and to discourage people from transitioning based on unrealistic expectations.

Transsexualism appears in the International Statistical Classification of Diseases and Related Health Problems (ICD, currently in its tenth edition). The ICD-10 incorporates "transsexualism", "dual role transvestism," and "gender identity disorder of childhood" into its gender identity disorder category. It defines transsexualism as "[a] desire to live and be accepted as a member of the opposite sex, usually accompanied by a sense of discomfort with, or inappropriateness of, one's anatomic sex, and a wish to have surgery and hormonal treatment to make one's body as congruent as possible with one's preferred sex."

Historically, transsexualism has also been included in the American Psychiatric Association's "Diagnostic and Statistical Manual of Mental Disorders" (DSM). With the DSM-5, transsexualism was removed as a diagnosis, and a diagnosis of gender dysphoria was created in its place. This change was made to reflect the consensus view by members of the APA that transsexuality is not in and of itself a disorder and that transsexual people should not be stigmatized unnecessarily. By including a diagnosis for gender dysphoria, transsexual people are still able to access medical care through the process of transition.

Similarly, the World Professional Association for Transgender Health (WPATH), and many transsexual people, have recommended the removal of transsexualism from the mental health chapter of the upcoming ICD, ICD-11 (due to be released in 2018). They argue that at least some mental health professionals are being insensitive by labelling transsexualism as "a disease", rather than the inborn trait which those who have it believe it to be. Principle 18 of The Yogyakarta Principles, a document of international human rights law, opposes such diagnosis as mental illness as medical abuse.

The current diagnosis for transsexual people who present themselves for medical treatment is gender dysphoria (leaving out those who have sexual identity disorders without gender concerns). According to the "Standards of care" formulated by the World Professional Association for Transgender Health (WPATH), formerly the Harry Benjamin International Gender Dysphoria Association, this diagnostic label is often necessary to obtain sex reassignment therapy with health insurance coverage, and the designation of gender identity disorders as mental disorders is not a license for stigmatization or for the deprivation of gender patients' civil rights.

Sexual maturation disorder is a disorder of anxiety or depression related to an uncertainty about one's gender identity or sexual orientation. The World Health Organization (WHO) lists sexual maturation disorder in the ICD-10, under "Psychological and behavioural disorders associated with sexual development and orientation".

Sexual orientation, by itself, is not a disorder and is not classified under this heading. It differs from ego-dystonic sexual orientation where the sexual orientation or gender identity is repressed or denied.

Biphobia is aversion toward bisexuality and toward bisexual people as a social group or as individuals. It can take the form of denial that bisexuality is a genuine sexual orientation, or of negative stereotypes about people who are bisexual (such as the beliefs that they are promiscuous or dishonest). People of any sexual orientation can experience or perpetuate biphobia, and it is a source of social discrimination against bisexual people.

Transmisogyny (sometimes trans-misogyny) is the intersection of transphobia and misogyny. Transphobia is defined as "the irrational fear of, aversion to, or discrimination against transgender or transsexual people". Misogyny is defined as "a hatred of women". Therefore, transmisogyny includes negative attitudes, hate, and discrimination of transgender or transsexual individuals who fall on the feminine side of the gender spectrum, particularly transgender women. The term was coined by Julia Serano in her 2007 book "Whipping Girl" and used to describe the unique discrimination faced by trans women because of "the assumption that femaleness and femininity are inferior to, and exist primarily for the benefit of, maleness and masculinity", and the way that transphobia intensifies the misogyny faced by trans women (and vice versa). It is said many trans women experience an additional layer of misogyny in the form of fetishization; Serano talks about how society views trans women in certain ways that sexualize them, such as them transitioning for sexual reasons, or ways where they’re seen as sexually promiscuous.Transmisogyny is a central concept in transfeminism and is commonly referenced in intersectional feminist theory. That trans women's femaleness (rather than only their femininity) is a source of transmisogyny is denied by certain radical feminists, who claim that trans women are not female.

Perhaps due to their perceived rarity, the dissociative disorders (including DID) were not initially included in the Structured Clinical Interview for DSM-IV (SCID), which is designed to make psychiatric diagnoses more rigorous and reliable. Instead, shortly after the publication of the initial SCID a freestanding protocol for dissociative disorders (SCID-D) was published. This interview takes about 30 to 90 minutes depending on the subject's experiences. An alternative diagnostic instrument, the Dissociative Disorders Interview Schedule, also exists but the SCID-D is generally considered superior. The Dissociative Disorders Interview Schedule (DDIS) is a highly structured interview that discriminates among various DSM-IV diagnoses. The DDIS can usually be administered in 30–45 minutes.

Other questionnaires include the Dissociative Experiences Scale (DES), Perceptual Alterations Scale, Questionnaire on Experiences of Dissociation, Dissociation Questionnaire, and the Mini-SCIDD. All are strongly intercorrelated and except the Mini-SCIDD, all incorporate absorption, a normal part of personality involving narrowing or broadening of attention. The DES is a simple, quick, and validated questionnaire that has been widely used to screen for dissociative symptoms, with variations for children and adolescents. Tests such as the DES provide a quick method of screening subjects so that the more time-consuming structured clinical interview can be used in the group with high DES scores. Depending on where the cutoff is set, people who would subsequently be diagnosed can be missed. An early recommended cutoff was 15-20. The reliability of the DES in non-clinical samples has been questioned.

Lesbophobia (sometimes lesbiphobia) comprises various forms of negativity towards lesbians as individuals, as couples, or as a social group. Based on the categories of sex, sexual orientation, lesbian identity, and gender expression, this negativity encompasses prejudice, discrimination, and abuse, in addition to attitudes and feelings ranging from disdain to hostility. As such, lesbophobia is sexism against women that intersects with homophobia and vice versa.

Until the 1990s, it tended to be described mostly as acrotomophilia, at the expense of other disabilities, or of the wish by some to pretend or acquire disability. Bruno (1997) systematised the attraction as factitious disability disorder. A decade on, others argue that erotic target location error is at play, classifying the attraction as an identity disorder. In the standard psychiatric reference "Diagnostic and Statistical Manual of Mental Disorders", text revision (DSM-IV-tr), the fetish falls under the general category of "Sexual and Gender Identity Disorders" and the more specific category of paraphilia, or sexual fetishes; this classification is preserved in DSM-5.

The fourth, revised edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) diagnoses DID according to the diagnostic criteria found in section 300.14 (dissociative disorders). It has also been found difficult to diagnose the disorder in the first place, due to there not being a universal agreement of the definition of dissociation. The criteria require that an adult be recurrently controlled by two or more discrete identities or personality states, accompanied by memory lapses for important information that is not caused by alcohol, drugs or medications and other medical conditions such as complex partial seizures. While otherwise similar, the diagnostic criteria for children also specifies symptoms must not be confused with imaginative play. Diagnosis is normally performed by a clinically trained mental health professional such as a psychiatrist or psychologist through clinical evaluation, interviews with family and friends, and consideration of other ancillary material. Specially designed interviews (such as the SCID-D) and personality assessment tools may be used in the evaluation as well. Since most of the symptoms depend on self-report and are not concrete and observable, there is a degree of subjectivity in making the diagnosis. People are often disinclined to seek treatment, especially since their symptoms may not be taken seriously; thus dissociative disorders have been referred to as "diseases of hiddenness".

The diagnosis has been criticized by supporters of therapy as a cause or the sociocognitive hypothesis as they believe it is a culture-bound and often health care induced condition. The social cues involved in diagnosis may be instrumental in shaping patient behavior or attribution, such that symptoms within one context may be linked to DID, while in another time or place the diagnosis could have been something other than DID. Other researchers disagree and argue that the existence of the condition and its inclusion in the DSM is supported by multiple lines of reliable evidence, with diagnostic criteria allowing it to be clearly discriminated from conditions it is often mistaken for (schizophrenia, borderline personality disorder, and seizure disorder). That a large proportion of cases are diagnosed by specific health care providers, and that symptoms have been created in nonclinical research subjects given appropriate cueing has been suggested as evidence that a small number of clinicians who specialize in DID are responsible for the creation of alters through therapy.

Transphobia is a range of negative attitudes, feelings or actions toward transgender or transsexual people, or toward transsexuality. Transphobia can be emotional disgust, fear, violence, anger or discomfort felt or expressed towards people who do not conform to society's gender expectations. It is often expressed alongside homophobic views and hence is often considered an aspect of homophobia. Transphobia is a type of prejudice and discrimination similar to racism and sexism, and transgender people of color are often subjected to all three forms of discrimination at once.

Child victims of transphobia experience harassment, school bullying, and violence in school, foster care, and social programs. Adult victims experience public ridicule, harassment including misgendering, taunts, threats of violence, robbery, and false arrest; many feel unsafe in public. A high percentage report being victims of sexual violence. Some are refused healthcare or suffer workplace discrimination, including being fired for being transgender, or feel under siege by conservative political or religious groups who oppose laws to protect them. There is even discrimination from some people within the movement for the rights of gender and sexual minorities.

Besides the increased risk of violence and other threats, the stress created by transphobia can cause negative emotional consequences which may lead to substance abuse, running away from home (in minors), and a higher rate of suicide.

In the Western world, there have been gradual changes towards the establishment of policies of non-discrimination and equal opportunity. The trend is also taking shape in developing nations. In addition, campaigns regarding the LGBT community are being spread around the world to improve acceptance; the "Stop the Stigma" campaign by the UN is one such development.

Attraction to disability or devotism is a sexualised interest in the appearance, sensation and experience of disability. It may extend from normal human sexuality into a type of sexual fetishism. Sexologically, the pathological end of the attraction tends to be classified as a paraphilia. (Note, however, that the very concept "paraphilia" continues to elude satisfactory definition and remains a subject of ongoing debate in both professional and lay communities) Other researchers have approached it as a form of identity disorder. The most common interests are towards amputations, prosthesis, and crutches.

Transmisogyny is generally understood to be caused by the social belief that men are superior to women. In "Whipping Girl", Julia Serano writes that the existence of trans women is seen as a threat to a "male-centered gender hierarchy, where it is assumed that men are better than women and that masculinity is superior to femininity". Gender theorist Judith Butler echoes this assumption, stating that the murder of transgender women is "an act of power, a way of re-asserting domination... killing establishes the killer as sovereign in the moment that he kills".

Trans women are also viewed as threatening the heterosexuality of cisgender men. In media, "deceivers" such as Dil, a transgender woman from the 1992 film "The Crying Game", have been observed to invoke outrage and male homophobia in an audience when their "true" maleness is unveiled.

As the disorder progresses in life, it can increase in severity, and cause other behaviors or actions in late adolescence and adulthood. “A strong and persistent cross-gender identification in adolescents and adults [can cause a] disturbance manifested by symptoms such as a stated desire to be the other sex, frequent passing as the other sex, desire to live or be treated as the other sex, or the conviction that he or she has the typical feelings and reactions of the other sex” (APA, 2000). This can cause severe conflict for the individual living in a society which endorses and enforces adherence to strict gender roles. In a more persistent disassociation with one’s own body or gender, someone can go to more extreme lengths to feel as though they are fulfilled or satisfied with themselves. This can lead these individuals to engage in behavior that displaces their emotions. These individuals may also seek to undergo sex reassignment surgery. “Persistent discomfort with his or her sex or sense of inappropriateness in the gender role of that sex in adolescents and adults [can cause a] disturbance manifested by symptoms such as preoccupation with getting rid of primary and secondary sex characteristics (e.g., request for hormones, surgery, or other procedures to physically alter sexual characteristics to simulate the other sex) or belief that he or she was born the wrong sex” (APA, 2000).

Apotemnophia / Body Integrity Disorder (BIID) is a is a rare, infrequently studied and highly secretive condition in which there is a mismatch between the mental body image and the physical body. Apotemnomphilia is characterized by an intense desire for amputation of a limb. Currently BIID is not included in the International Statistical Classification of Diseases 11 or the Diagnostic and Statistical Manual of Mental Disorders IV. It is often not known to surgeons, neurologists and psychiatrists. BIID individuals typically avoid healthcare and often act out their desires by pretending they are disabled or perform actual self-amputation.

A 2012 study concluded, based on interviews with 54 individuals, that the main rationale for their desire for body modification (amputation) was to feel complete or to feel satisfied inside. Based on the results of the survey, researchers concluded that psychotherapy was often supportive, but did not help diminishing BIID symptoms. Individuals reported that antidepressants were helpful in reducing depressive symptoms related to BIID, but that antipsychotics were not. Actual amputation of the limb was effective in all 7 cases who had surgical treatment.

Homophobia encompasses a range of negative attitudes and feelings toward homosexuality or people who are identified or perceived as being lesbian, gay, bisexual or transgender (LGBT). It has been defined as contempt, prejudice, aversion, hatred or antipathy, may be based on irrational fear, and is often related to religious beliefs.

Homophobia is observable in critical and hostile behavior such as discrimination and violence on the basis of sexual orientations that are non-heterosexual. Recognized types of homophobia include "institutionalized" homophobia, e.g. religious homophobia and state-sponsored homophobia, and "internalized" homophobia, experienced by people who have same-sex attractions, regardless of how they identify.

Negative attitudes toward identifiable LGBT groups have similar yet specific names: lesbophobia is the intersection of homophobia and sexism directed against lesbians, biphobia targets bisexuality and bisexual people, and transphobia targets transgender and transsexual people and gender variance or gender role nonconformity. According to 2010 Hate Crimes Statistics released by the FBI National Press Office, 19.3 percent of hate crimes across the United States "were motivated by a sexual orientation bias." Moreover, in a Southern Poverty Law Center 2010 "Intelligence Report" extrapolating data from fourteen years (1995–2008), which had complete data available at the time, of the FBI's national hate crime statistics found that LGBT people were "far more likely than any other minority group in the United States to be victimized by violent hate crime."

The term "homophobia" and its usage have been criticized by several sources as unwarrantedly pejorative