A Place for Sexual Dysfunctions in an Empirical Taxonomy of Psychopathology

Abstract

Sexual dysfunctions commonly co-occur with various depressive and anxiety disorders. An emerging framework for understanding the classification of mental disorders suggests that such comorbidity is a manifestation of underlying dimensions of psychopathology (or “spectra”). In this review, we synthesize the evidence that sexual dysfunctions should be included in the empirical taxonomy of psychopathology as part of the internalizing spectrum, which accounts for comorbidity among the depressive and anxiety disorders. The review has four parts. Part 1 summarizes the empirical basis and utility of the empirical taxonomy of psychopathology. Part 2 reviews the prima facie evidence for the hypothesis that sexual dysfunctions are part of the internalizing spectrum (i.e., high rates of comorbidity; shared cognitive, affective, and temperament characteristics; common neural substrates and biomarkers; shared course and treatment response; and the lack of causal relationships between them). Part 3 critically analyzes and integrates the results of the eight studies that have addressed this hypothesis. Finally, Part 4 examines the implications of reconceptualizing sexual dysfunctions as part of the internalizing spectrum, and explores avenues for future research.

Conflict of Interest

The authors declare that they have no conflict of interest.

Funding

This research was supported in part by a National Institute of Drug Abuse (NIDA) training grant supporting the work of Miriam Forbes (T320A037183). NIDA had no further role in the study design; in the collection, analysis, and interpretation of data; in writing; nor in the decision to submit the manuscript for publication.

Notes

¹ Symptoms of sexual dysfunctions—as delineated in the Diagnostic and Statistical Manual of Mental Disorders (DSM)—are collectively referred to as “low sexual function” throughout this review. This label is used to differentiate between diagnosed sexual dysfunctions with associated clinically significant distress, and the measurement of symptoms of these disorders without a formal diagnosis (see Bancroft, Loftus, & Long, 2003; Lutfey et al., 2009). Where diagnosed disorders (i.e., with accompanying distress) are referred to, the term “sexual dysfunctions” is used to correspond with the DSM.

² In this review, mental disorders (including sexual dysfunction) are conceptualized as syndromes indicated by groups of observable clinical symptoms and signs that commonly occur together. In this paradigm, the disorder itself is not observable; it is measurable via its manifestations only, which indicate the severity of the disorder on a continuous spectrum from “normal” to “disordered.” The studies we review based on diagnoses (coded as present or absent) therefore have better criterion validity to the DSM disorder constructs but lose valuable information about symptom variation above and below the diagnostic threshold (Krueger et al., 1998). As such, we synthesize studies that focused on diagnosed disorders alongside studies that focused on continuous symptom measures, interpreting them together (i.e., with diagnoses interpreted as dichotomous indicators of disorder severity).

³ This is how we use the term internalizing disorders in subsequent sections.

⁴ In contrast, the co-occurrence of sexual dysfunctions with other domains of psychopathology has been attributed to medications that are commonly used to treat schizophrenia and mania, for example (e.g., lithium and antipsychotics; Baggaley, 2008; De Boer, Castelein, Wiersma, Schoevers, & Knegtering, 2015; Elnazer, Sampson, & Baldwin, 2015).

⁵ These estimates included the domains of desire, arousal sensation, lubrication, orgasm, and sexually related distress for women, and the domains of erectile function, ejaculatory control and associated distress, and sexual satisfaction (operationalizing low sexually related distress) for men. The cognitive component of female sexual arousal had stronger relationships with the model (75–84% of its variance was accounted for by a longitudinal internalizing spectrum model), as expected. In contrast, female sexual pain and male sexual desire had weaker relationships (8–11% and 10–16% of their variance was accounted for, respectively), which is discussed in detail in Part 3.

⁶ The models were not tested using a one-week or six-month gap for men because the subsample sizes were not large enough (Forbes, Baillie, & Schniering, 2016b).

Additional information

Funding

This research was supported in part by a National Institute of Drug Abuse (NIDA) training grant supporting the work of Miriam Forbes (T320A037183). NIDA had no further role in the study design; in the collection, analysis, and interpretation of data; in writing; nor in the decision to submit the manuscript for publication.