What is transsexualism?
Transsexualism is a form of gender dysphoria or a gender identity disorder (GID) in which a person possesses a strong and enduring desire to live and be accepted as a member of the opposite sex. Transsexuals feel a persistent discomfort with their anatomical sex and a sense of unease in the gender role of that sex. They wish to have hormonal treatment and gender reassignment surgery - a sex change - to acquire the physical characteristics of their psychological sex. The term transsexual first emerged in the 1950s and had gained widespread acceptance within the medical profession by the mid-1960s.

Is it a form of mental illness?
Although gender dysphoria is listed in the US Diagnostic and Statistical Manual on Mental Disorders, most transsexuals and UK transgender psychiatrists do not consider transsexualism to be a mental illness. However, due to the discrimination and prejudice they face many transsexuals do suffer from mental health problems.

How many transsexuals are there?
A report from the Interdepartmental Working Group on Transsexual People in 2000 estimated that there were 1,300-2,000 male-to-female and 250-400 female-to-male transsexuals in the UK. However the transgender lobby group, Press for Change, puts the numbers far higher. It estimates there are 5,000 post-operative transsexuals in this country.

What treatment is there for transsexuals?
The currently accepted and effective model of treatment involves hormonal therapy and surgical reconstruction, and may include counselling and other forms of psychotherapy. There are minimum guidelines which set eligibility criteria for patients. But the course of treatment can be tailored to the individual's needs, and is usually negotiated among the patient's GP and the psychiatrist and surgeon providing specialist care.

What does hormonal therapy involve?
Male-to-female patients treated with oestrogens can expect to experience: breast growth, some redistribution of body fat in line with a more feminine appearance; decreased upper body strength; softening of the skin; a decrease in body hair; slowing or stopping of loss of scalp hair; decreased fertility and testicular size; and less frequent, less firm erections. Female-to-male patients treated with testosterone can expect the following permanent changes: a deepening of the voice; clitoral enlargement; reduction in breast size; more facial and body hair; and male pattern baldness. Reversible changes include: increased upper body strength; weight gain; increased sex drive; and decreased hip fat.

What surgery is performed?
Depending on the appearance and health of the patient, surgery for male-to-female transsexuals may include: removal of the penis (penectomy); construction of a vagina (vaginoplasty); removal of the testicles (orchidectomy); construction of a clitoris (clitoroplasty); and possible breast augmentation; nose reshaping (rhinoplasty); cosmetic surgery such as hair transplants or facial remodelling; shaving of the Adam's apple (thyroid chrondroplasty) and raising the pitch of the voice (crico-thyroid approximation). For female-to-male (FTMs) transsexuals, surgery may include removal of the womb and ovaries (hysterectomy and oophorectomy); removal of the breasts (bilateral mastectomy); and possibly construction of a penis (phalloplasty). Only a small number of FTM transsexuals undergo genital surgery because - at best - the results only vaguely resemble a penis.

What other treatments are there?
Male-to-female transsexuals may undergo electrolysis to remove their beard and body hair. Transsexuals might also seek speech therapy to help attune their voices to their acquired gender.

Are there any rules governing this treatment?
Although there are no legally binding rules, standards of care have been drawn up by the Harry Benjamin International Gender Dysphoria Association (HBIGDA). The association has established standards of care for the treatment of GIDs, which are generally accepted by psychiatrists across the world. These standards are revised to take into account new scientific information, and were last updated in 2001. They provide "flexible directions" for the treatment of transsexuals, which may be modified in line with a patient's particular needs and circumstances. They include minimum eligibility requirements for some procedures, such as the prescription of hormones and referrals for genital surgery.

What do the guidelines state?
With regards to hormonal therapy, the HBIGDA guidelines set three criteria. Firstly, patients should be over 18. Secondly, they should be aware of the effects and risks of taking the drugs. And thirdly, they should have documented proof that they were living in their desired gender role for at least three months (known as the "real life experience"); or have undergone a minimum of three months of psychotherapy. With regards to surgery, there are six eligibility criteria, the most important of which are that the patient should be a legal adult; have had 12 months of continuous hormone therapy; and have lived in their desired gender role for a year - a period known as the real life experience. There are also two readiness criteria. Patients should demonstrate that they are consolidating their gender identity, and enjoy better mental health as a result of dealing effectively with work, their family and relationships. Psychiatrists are required to check that patients meet these criteria.

Why are the guidelines important?
Some of the procedures are irreversible, so patients need to fully understand and be prepared for treatment. Some of the side-effects of hormone therapy, such as an increase in blood clotting, can be life threatening to patients in poor health, for example those with heart disease. Some people with psychotic illnesses, such as schizophrenia and manic depression, may mistakenly believe they are transsexual, but a thorough psychological assessment should prevent misdiagnosis. Transgender psychiatrists also admit that the boundaries between transsexualism, transvestism and homosexuality are not entirely clear to them. The guidelines help them to determine which patients are truly transsexual.

Are the guidelines officially recognised in the UK?
The standards of care are "generally supported" by the Royal College of Psychiatrists (RCP), though it does not formally recognise them. There is disagreement among psychiatrists over the period patients should spend living as their desired sex prior to hormone therapy and surgery. Dr Brian Ferguson, a member of the RCP's working party on GID, supports a two-year real life experience prior to genital surgery - twice the length of time recommended by the HBIGDA. The college is working towards drawing up UK guidelines in partnership with the transgendered community. Draft guidelines are expected to be published early next year.

What do transsexuals make of the guidelines?
Again, there is not a consensus of opinion. Some transsexuals believe that psychiatrists stick too strictly to the eligibility criteria, without taking into account the circumstances and history of the individual patient; others believe they are sensible precautionary measures.