Toward an Improved Nosology of Sexual Dysfunctions in DSM-V

Sexual dysfunctions as distinct syndromes were first identified in DSM-III in 1980. At that time, sets of criteria were specified for inhibited sexual desire, inhibited sexual excitement, inhibited female orgasm, inhibited male orgasm, premature ejaculation, dyspareunia, and functional vaginismus. The sexual dysfunctions roughly corresponded to the phases of the sexual response cycle introduced by Masters and Johnson¹ with the exception of disorders of sexual desire. The concept of inhibited sexual desire was separately introduced by Lief² and Kaplan³ in 1977. It is important to note that some have questioned the wisdom of anchoring the diagnoses of sexual dysfunction in the phases of sexual response cycle, since DSM-defined sexual dysfunctions frequently overlap, especially in the area of female sexual dysfunction.⁴

Subsequent revisions of these categories have consisted of name changes (eg, inhibited sexual desire being changed to hypoactive sexual desire disorder), the addition of sexual aversion disorder (a diagnosis rarely used), the addition of subtypes (lifelong vs acquired, generalized vs situational, due to psychological factors vs due to combined factors) and minor modification of criteria sets. In DSM-IV, 2 additional categories were added, namely substance-induced sexual dysfunction (eg, SSRI-induced anorgasmia) and sexual dysfunction due to a general medical disorder (eg, erectile dysfunction due to multiple sclerosis or due to diabetes mellitus). The diagnostic criteria for each sexual dysfunction are operationally defined in a similar way.

• Criterion A defines the specific psychophysiological impairment (for example, lack of orgasm or erectile dysfunction).
• Criterion B requires that the disturbance causes marked distress or interpersonal difficulty.
• Criterion C requires that the dysfunction is not better accounted for by another Axis I disorder or general medical condition and is not solely due to a substance effect (medication use or abuse).

The requirement of exclusion of sexual dysfunction due to another Axis I disorder is an interesting and puzzling concept. The association of sexual dysfunctions with various physical illnesses is well known and is basically acknowledged by the creation of the "sexual dysfunction due to general medical condition" diagnostic category. Lately, we have increasingly appreciated the association of sexual dysfunctions with various psychiatric disorders, eg, major depression (well known for a long time) or schizophrenia. It is a bit puzzling and inconsistent not to establish the diagnostic category of "sexual dysfunction due to mental disorder" (especially because sexual dysfunction due to substance abuse could be classified as such, and even subclassified as "with onset during intoxication").

As with other classes of disorders in DSM, the category of sexual disorder not otherwise specified is included at the end for those problems/behaviors that do not meet criteria for any specific sexual disorder, eg, marked feelings of inadequacy concerning sexual performance or other traits related to self-imposed standards of masculinity or femininity.

Since the publication of DSM-IV-TR, new research on sexual disorders has shed additional light on issues such as distress and duration. Research results will no doubt be reflected in the upcom- ing DSM-V. In this article, we briefly review the limitations of the current criteria for sexual disorders and suggest revisions that might be made in DSM-V.

Of interest, while DSM-IV and other criteria of sexual dysfunction are widely used, their validity and reliability have not been properly tested. DSM criteria also differ slightly from another set of sexual dysfunction diagnostic criteria—those of the ICD-10 Classification of Mental and Behavioural Disorders diagnostic criteria (the ICD-10 criteria include the duration criterion [6 months for most], which is not included in the DSM classification).

Through all of the iterations of the DSM classification of sexual dysfunctions, several pervasive problems have remained. One major issue is the absence of operational criteria for the disorders. For example, premature ejaculation is defined as "persistent or recurrent ejaculation before, on, or shortly after penetration and before the person wishes it." From this definition, it is unclear exactly what constitutes "shortly after penetration." At this point, data regarding the average ejaculatory latency of men in multiple countries including the United States exist and, thus, we should be able to set specific times from penetration to ejaculation for the diagnosis of premature ejaculation.⁵ Similar lack of specificity plagues the other diagnoses.