13 Psychiatry of sexuality

Introduction

Psychosexual disorders can be divided into disorders of sexual preference and disorders of sexual functioning. The forensic aspects of the former are addressed in Chapter 21.

Disorders of sexual preference are strongly culturally determined. For example, in the early part of the 20th century masturbatory insanity was an accepted diagnosis derived from the observation of incarcerated ‘lunatics and mental defectives’. This term was dropped when, first, the malign influence of sensory deprivation in increasing the likelihood of repetitive behaviours was realized, and secondly when masturbation became more accepted as a part of ‘normal’ human sexuality in Western culture. Similarly, homosexuality was included in the ninth International Classification of Diseases but is not in ICD-10.

Disorders of sexual functioning were not properly identified until the pioneering work of Masters and Johnson in the USA examined human physiological responses during sexual behaviour, and put forward a four-stage model of sexual arousal.

Sexual response

Before considering the sexual response it is important to be familiar with the anatomy of the human genitalia. The important structures are depicted in Figures 13.1 and 13.2. It must be remembered, however, that sexual responsiveness is not confined to the genitalia but can and does involve the whole body. Indeed, this is an important consideration in some of the treatments for sexual dysfunction.

Figure 13.1 • Female genitalia.

Figure 13.2 • Male genitalia.

The four phases identified by Masters and Johnson are excitement, plateau, orgasm and resolution. Kaplan proposed instead a three-phase model of desire, excitement and orgasm. Kaplan introduced desire (also referred to as libido, or sexual interest) as an additional concept because of her clinical observations in the treatment of people with sexual dysfunction that problems could remain despite normal physiological responses in the other phases. Excitement and orgasm phases were distinguished because of their predominant mediation by the parasympathetic and sympathetic nervous systems respectively.

In Masters and Johnson’s model:

• Excitement phase – arousal develops in response to sexual stimulation (fantasy as well as actual). In the female there is rapid vaginal lubrication, expansion and distension of the inner part of the vagina, swelling and elongation of the clitoris, some elevation of the uterus and, in some women, nipple erection. In the male there is erection of the penis, thickening of the scrotal skin and some elevation of the testes. In both sexes there is some increase in blood pressure and pulse.

• Plateau phase – an intensification of excitement from which orgasm can occur. In the female there is breast and areolar enlargement, swelling of the outer third of the vagina, withdrawal of the clitoral head and shaft into the clitoral hood, and a reddening of the labia minora. In men there is some colour change of the penis head and enlargement and further elevation of the testes. In both sexes there is an increase in muscle tension, pulse and blood pressure. In some there is a ‘flush’ across the front of the trunk and head on some occasions.

• Orgasm phase – involuntary release of sexual tension. In the female there is rhythmic contraction of the outer third of the vagina and contractions of the uterus. In the male there is ejaculation of the prostate, seminal vesicles, etc. to produce seminal fluid (ejaculatory inevitability), followed by rhythmic contractions of the urethra to expel the semen. In both sexes maximal pulse, blood pressure and respiration are produced.

• Resolution phase – in which the bodily status returns to normal. In women the cervix is lowered to the vaginal floor and there is some gaping of the cervical os. The resolution phase may occur without orgasm or plateau phases.

The relative timings of each of these phases are shown in Figure 13.3. In females there may be rapid response to reach orgasm (e.g. during masturbation). In either sex there may be excitement and plateau without orgasm, although this is much more common in the female. In males there is a refractory period after orgasm during which a further orgasm cannot occur. The length of this increases with age.

Figure 13.3 • Relative timings of Masters and Johnson’s phases of the sexual response.

Classification and diagnosis of sexual disorders

The ICD-10 category for disorders of sexual preference is shown in Table 13.1 and the DSM-IV-TR category for paraphilias in Table 13.2. These may variously be referred to as paraphilias, perversions or sexual deviances, although the latter two labels have become regarded as stigmatizing in many circles, perhaps because of the overlap between these disorders and sexual offences (see Chapter 21). Disorders of sexual preference are characterized by sexually arousing fantasies, urges and/or activities, which are not part of normative sexual functioning and which interfere with reciprocal affectionate activity. Some of these activities are illegal, but this can vary between jurisdictions. Some of the activities, such as voyeurism and exhibitionism, can present to a lesser degree in ‘normal’ sexuality, but are not persistent or preferred. Mental illness may be associated with the disorder of sexuality and should be diagnosed if present.

Table 13.1 I CD-10 classification: F65 Disorders of sexual preference

F65.0 Fetishism

Reliance on some non-living object as a stimulus for sexual arousal, e.g. articles of clothing, particular texture such as rubber or plastic

F65.1 Fetishistic transvestism

Wearing of opposite-sex clothes for sexual excitement

F65.2 Exhibitionism

Recurrent or persistent tendency to expose the genitalia to strangers (usually of the opposite sex) or to people in public places

F65.3 Voyeurism

Recurrent or persistent tendency to look at people engaging in sexual or intimate behaviour such as undressing

F65.4 Paedophilia

Sexual preference for children, usually prepubertal or early pubertal

F65.5 Sadomasochism

Preference for sexual activity that involves bondage or the infliction of pain or humiliation. Preference to be the recipient is masochism, to be provider is sadism

F65.6 Multiple disorders of sexual preference

Most common combination is fetishism, transvestism and sadomasochism

F65.7 Other disorders of sexual preference, e.g.

Frotteurism: rubbing up against people for sexual stimulation in crowded public places

Necrophilia: preference for sexual activity with corpses

Zoophilia: preference for sexual activity with animals (bestiality)

Scotophilia: arousal from viewing of sexual scenes and genitalia (as with viewing of pornography)

Telephone scatalogia: making of obscene telephone calls

Table 13.2 DSM-IV-TR Paraphilias

302.83 Sexual masochism

302.84 Sexual sadism

302.3 Transvestic fetishism

302.82 Voyeurism

302.9 Paraphilia NOS

NOS, not otherwise specified

Gender identity disorders are classified in ICD-10 under category F64, and include transsexualism, dual-role transvestism and gender identity disorder of childhood. Transsexualism is a desire to live, function and be accepted as a member of the opposite sex. There is a conviction that ‘wrong’ gender assignment has occurred and a sense of discomfort with anatomical sexual characteristics. This leads to pursuit of hormonal treatment and surgery to make the external appearance as congruent as possible with the preferred sex. Such features usually are present from childhood, but must be present persistently for at least two years before the ICD-10 diagnosis can be made. Psychiatrists are usually extensively involved in assessment where gender reassignment surgery is being contemplated. Dual-role transvestism is the wearing of clothes of the opposite sex for part of the time without the wish permanently to change sex and without sexual excitement (cf. fetishistic transvestism, F65.1). Gender identity disorder of childhood is rare, and refers to a child’s desire to be the opposite sex, typically from the preschool years but certainly before puberty. There is a preoccupation with activities and dress usually associated with the opposite sex but no associated sexual excitement.

The ICD-10 and DSM-IV-TR classifications of sexual dysfunction (Tables 13.3 and 13.4) refer to disorders of normal sexual functioning. Anxiety, depression and other psychiatric disorders, which all have an effect on sexual responsiveness, should be considered in assessing sexual dysfunction and diagnosed if appropriate. The anergia of schizophrenia can include a reduction in sexual drive.

Table 13.4 DSM-IV-TR classification of sexual dysfunctions