Feasibility of a Cognitive-Behavioral Couple Therapy Intervention for Sexual Interest/Arousal Disorder

ABSTRACT

Female sexual interest/arousal disorder (SIAD) is strongly influenced by interpersonal factors; however, there are no empirically-supported, couple-based sex therapy interventions for this disorder. This pre-registered study tested the feasibility of a cognitive-behavioral couple therapy (CBCT) intervention for SIAD. A sample of 19 couples in which a female partner was diagnosed with SIAD completed a 16-session CBCT intervention delivered online by therapists with PhD-level training in clinical psychology. Women with SIAD (M_age = 43.47, SD = 12.76) and their partners (M_age = 43.74, SD = 11.68) were in long-term relationships (M = 13.86, SD = 9.15). The CBCT sessions were video recorded and independently coded for treatment manual adherence and therapists reported on the completion of in-session and homework exercises. Participants completed measures of treatment satisfaction following the intervention as well as dyadic sexual desire (women with SIAD only) and sexual distress prior to treatment, post-treatment, and at 6 months follow-up. The therapists exhibited a high level of adherence to the treatment manual and couples had high rates of homework completion. Moreover, couples had low dropout rates, high attendance rates, and reported moderately high global treatment satisfaction and high satisfaction with virtual care. Women with SIAD reported large improvements in dyadic sexual desire and sexual distress from pre-treatment to post-treatment and pre-treatment to 6-month follow-up. Partners reported moderate and small improvements in sexual distress for post-treatment and 6-month follow-up, respectively. Results support the feasibility of an evidence-based CBCT intervention for SIAD and the need for a randomized clinical trial of the intervention.

Low sexual desire is the most common sexual difficulty among women, with large, representative samples showing that 30% to 40% of adult women have experienced this concern in the past year (Mitchell et al., 2013; Quinn-Nilas et al., 2018), and that 7% to 12% of women reported low sexual desire accompanied by significant distress (Shifren et al., 2008). Despite the high prevalence of distressing low sexual desire and the associated psychological, sexual, and relational consequences experienced by women and their partners (Rosen et al., 2019), relatively few evidence-based treatment options are available. Pharmacological agents have shown limited efficacy (Brotto, 2017; Jaspers et al., 2016), and although individual-oriented psychotherapies, such as cognitive-behavioral therapy and mindfulness-based interventions, show promise, they neglect the interpersonal context within which distressing low sexual desire often occurs for women in partnered relationships. Clinical and theoretical models highlight a significant interpersonal component involved in distressing low sexual desire and emphasize the need for empirically supported couple-based interventions (Bitzer et al., 2013; Mark & Lasslo, 2018; McCarthy et al., 2018; Rosen & Bergeron, 2019). The purpose of the current study was to test the feasibility of a novel cognitive-behavioral couple therapy for sexual interest/arousal disorder.

Sexual interest/arousal disorder¹ (SIAD) was introduced in the DSM-5 to replace hypoactive sexual desire disorder (HSDD) and female sexual arousal disorder, due in part to significant overlap in the experiences of sexual desire and subjective sexual arousal among women (Brotto, 2010; Graham, 2010). Individuals diagnosed with SIAD endorse three or more symptoms for at least six months, accompanied by significant distress and not better accounted for by a psychiatric or medical condition (American Psychiatric Association, 2013). Possible symptoms of SIAD include low sexual desire, few/no sexual thoughts, no initiation of sexual behavior or lack of receptivity to partner invitations, lack of pleasure during sexual activity, lack of responsive desire to sexual cues, and difficulties with physical sexual arousal (APA, 2013). There is symptom and diagnostic overlap between HSDD and SIAD (e.g., absent/reduced interest in sexual activity, absent/reduced sexual fantasies); however, evidence suggests that women with SIAD exhibit more severe symptoms (O’Loughlin et al., 2018).

Pharmacological agents, including flibanserin and bremelanotide, were tested and subsequently approved by Health Canada and the US Food and Drug Administration for the treatment of HSDD (Fisher & Pyke, 2017; Kingsberg, 2014). However, re-analyzed trial data and meta-analytic findings show that these medications produce unwanted side effects and minimal benefits compared to placebo (Jaspers et al., 2016; Spielmans, 2021). In contrast, meta-analyses of randomized clinical trials (RCTs) for women’s sexual dysfunction show that cognitive-behavioral therapy interventions for HSDD produce large improvements in sexual desire (Cohen’s d = 0.91; Frühauf et al., 2013; Günzler & Berner, 2012) and mindfulness-based interventions produce moderate improvements (d = 0.55; Banbury et al., 2021). Together, these meta-analyses show that psychological interventions improve distressing low sexual desire, which is a key symptom in SIAD.

Among the RCTs for women’s sexual dysfunction were a series of studies from the 1990s testing couple therapies for HSDD (Hurlbert, 1993; Hurlbert et al., 1993; Macphee et al., 1995; Trudel et al., 2001), most of which were group-based therapies delivered to multiple couples simultaneously. These studies showed that couple-based interventions yielded greater improvements than individual-only treatment for HSDD (Hurlbert et al., 1993) or a waitlist control group (Macphee et al., 1995; Trudel et al., 2001). These findings align with clinical and theoretical models suggesting that distressing low sexual desire among women in partnered relationships should be conceptualized as a couple-based issue (Basson, 2001; Baumeister, 2000; Prekatsounaki et al., 2022; Rosen & Bergeron, 2019).

Recently, dyadic studies have confirmed that interpersonal factors, such as sexual motivation, sexual communication, relational self-expansion, and emotion regulation, are diminished among individuals with SIAD or associated with couples’ adjustment to the sexual difficulty (Bockaj et al., 2019; Dubé et al., 2019; Hogue et al., 2019; Raposo et al., 2020; Rosen et al., 2019, 2020). In these studies, partners’ experiences were uniquely linked to their own outcomes, and in some cases the outcomes of women with SIAD (Rosen et al., 2020). Importantly, partners of women with SIAD reported lower sexual and relationship satisfaction, poorer sexual communication, and higher sexual distress compared to partners of women without a sexual dysfunction, underscoring that partners are also affected by this condition (Rosen et al., 2019). Together, these studies inform dyadic models of sexual dysfunction and point to the need for couple-based sex therapy to treat individuals with SIAD and their partners (Mark & Lasslo, 2018; Rosen & Bergeron, 2019).

Notably, previous couple-based therapies for HSDD were not grounded in theory or empirical evidence from more recent dyadic research. Also, updated approaches to couple-based sex therapy for low sexual desire focus on desire discrepancy, rather than treating SIAD (Kleinplatz et al., 2020; McCarthy & Oppliger, 2019), leaving a gap in care options for couples coping with clinically low sexual desire/arousal. Furthermore, extant interventions for HSDD or desire discrepancy do not include manualized treatment protocols, which poses a barrier to testing for treatment adherence and efficacy in clinical trials.

Cognitive-behavioral couple therapy (CBCT) has been widely applied to the treatment of couples’ relationship distress and individuals’ psychiatric disorders, including anxiety, eating, mood, post-traumatic stress, and obsessive-compulsive disorders (Fischer & Baucom, 2018). As a treatment modality, CBCT builds and extends upon the principles of individual cognitive-behavioral therapy to target unhelpful cognitions and behaviors as well as address difficulties with emotional experiences within the couple (Fischer & Baucom, 2018). In an RCT, Bergeron et al. (2021) compared CBCT to a common medical treatment for women’s genito-pelvic pain/penetration disorder, which is a condition associated with low sexual desire/arousal. They found that CBCT was efficacious for reducing pain during intercourse as well as improving sexual and psychological difficulties in both members of the couple (Bergeron et al., 2021). In contrast to studies of group-based couple therapies for HSDD (Hurlbert, 1993; Hurlbert et al., 1993; Trudel et al., 2001) or desire discrepancy (Kleinplatz et al., 2020), CBCT can be tailored to couples’ unique experiences managing sexual desire in their specific relationship. Furthermore, this couple-based treatment aligns with the Interpersonal Emotion Regulation Model of women’s sexual dysfunction, which posits that interpersonal risk factors (e.g., poor sexual communication skills) affect couples’ co-regulation of emotions and in turn their sexual and relationship outcomes (Rosen & Bergeron, 2019). Since interpersonal factors can be readily targeted through cognitive and behavioral treatment strategies, CBCT is a promising framework to address sexual and relationship difficulties among couples coping with SIAD.

Current Study

The purpose of this pre-registered study was to test the feasibility of a manualized CBCT intervention for individuals with SIAD and their partners. We assessed the feasibility of administering the manualized intervention based on therapists’ adherence to the treatment manual and couples’ homework completion. To examine acceptability of the intervention, we assessed couples’ session attendance rate and self-reported treatment satisfaction. We also assessed for improvements in clinical outcomes and hypothesized that CBCT would result in improvements from pre-treatment to post-treatment and pre-treatment to 6-month follow-up for dyadic sexual desire for a partner among individuals with SIAD and sexual distress for both members of the couple.

Method

Participants

Participants were 19 cisgender women² who were diagnosed with SIAD as part of their eligibility screening for the study, and their partners. Couples were recruited from two sites in metropolitan Canadian cities between October and December 2021. Participants with low sexual desire/arousal were recruited from a waitlist at a psychology private practice (9 anglophone couples from Site A) or self-referred to the study in response to a French news article about the second author and couples-based sex therapy (10 francophone couples from Site B). Across the two sites the recruitment rate was ~ 6 couples/month, which allowed for staggered intake appointments with the study therapists. The clinical and sociodemographic characteristics of the sample are shown in Table 1.

Table 1. Clinical and sociodemographic characteristics (n = 19 couples).

	SIAD M (SD) or n (%)	Partners M (SD) or n (%)
Duration of low desire/arousal (years)	5.49 (4.58)
Age (years)	43.47 (12.76)	43.74 (11.68)
Relationship status
Married	10 (52.63%)
Cohabitating	7 (36.84%)
Committed but not cohabitating	2 (10.53%)
Relationship duration (years)	13.86 (9.15)
Partner gender
Man	18 (94.74%)
Woman	1 (5.26%)
Number of children at home	1.00 (1.2)
Cultural and racial/ethnic background
French Canadian	9 (47.37%)	9 (47.37%)
English Canadian	7 (36.84%)	8 (42.11%)
White	6 (31.58%)	6 (31.58%)
Latin American	2 (10.53%)	2 (10.53%)
American	1 (5.26%)	0
Brazilian	1 (5.26%)	0
Southeast Asian	1 (5.26%)	0
East Asian	0	1 (5.26%)
Western European	0	1 (5.26%)
Education (years)	18.89 (3.48)	17.63 (3.51)
Household annual income
$0–39,999	0
$40,000–79,999	3 (15.79%)
$80,000–119,999	4 (21.05%)
$120,000–159,999	2 (10.53%)
$160,000–199,999	4 (21.05%)
> $200,000	6 (31.58%)

For culture and race/ethnicity participants could choose more than one option; thus, percentages add up to more than 100%. M = mean. n = number of participants. SD = standard deviation.

Inclusion criteria required that an individual in the couple meet the DSM-5 diagnostic criteria for SIAD, which was assessed by a clinical interview (see Procedure for description of the diagnostic process). Also, inclusion criteria specified that the individual with low sexual desire/arousal was assigned female at birth and that both couple members be 18 years or older, fluent in English or French, in a committed relationship for at least one year, planning to live in the same city as each other for the coming year, and have a minimum of four in-person contacts/week to ensure opportunities for sexual activity and homework completion. Individuals with low sexual desire/arousal were excluded from participation if they did not have any prior sexual experience, had a history of genital or pelvic surgeries (e.g., hysterectomy) that affected their sexual desire, were pregnant, breastfeeding, or within one year postpartum due to possible effects on sexual desire (Schlagintweit et al., 2016), self-reported a physical illness or mental disorder that interfered with their daily functioning, or were actively engaged in another treatment for SIAD. Each member of the couple was assessed for anxiety and depressive symptoms as well as relationship distress in the pre-treatment survey. Couples were ineligible for the study if either member reported severe relationship distress (e.g., physical violence, sexual coercion, emotional abuse) or moderate to severe depressive symptoms on the Hospital Anxiety and Depression Scale (Zigmond & Snaith, 1983); there were no exclusion criteria based on anxiety symptoms. A flowchart of participation is presented in Figure 1.

Figure 1. Flowchart of participation.

Procedure

This study was approved by the research ethics board at Dalhousie University (Project # 1027040) and Université de Montréal (Project CEREP-21-079-D). Eligibility was assessed in three stages: (1) A brief telephone screening interview and (2) a clinical interview for SIAD for individuals with low sexual desire/arousal as well as (3) the pre-treatment survey for both members of the couple. Individuals with low sexual desire/arousal completed the telephone screening interview to receive information about the study and establish preliminary eligibility, then provided informed consent to continue with the eligibility assessment process and the study, if they were screened as eligible. A doctoral student in clinical psychology administered the structured clinical interview for SIAD, which was based on DSM-5 diagnostic criteria and has been used in other studies to diagnose SIAD (Rosen et al., 2019), under the supervision of the second or last author, who are both psychologists with advanced training in assessing for sexual dysfunction. Eligible women diagnosed with SIAD, then their partner, completed the pre-treatment survey, which assessed exclusion criteria (i.e., moderate to severe depression, severe relationship distress) and pre-treatment outcomes in both members of the couple. Partners provided informed consent for the study at the beginning of the pre-treatment survey. Couples completed outcome surveys independently from one another at pre-treatment, immediately post-treatment, and at 6-month follow-up. The couples received the CBCT intervention free of charge and each couple member received $15 CAD by electronic money transfer per survey for a total of $45 CAD per participant.

Intervention

The cognitive-behavioral couple therapy (CBCT) intervention consisted of 16 × 60-minute sessions; the first session was extended by 15 minutes to facilitate a longer intake assessment by the study therapists. The first 14 sessions were scheduled weekly and the final two sessions were scheduled bi-weekly to allow for tapering before therapy termination, resulting in a total treatment duration of 18 weeks. The intervention was offered online to both adhere to COVID-19 restrictions at the time and to increase accessibility for those living outside of urban centers. All sessions took place on Zoom Pro and were video recorded for clinical supervision and adherence coding. Couple members joined sessions from the same room to facilitate dyadic interactions (e.g., eye contact during communication exercises, physical touch as needed to provide comfort to a partner during session). The treatment manual was adapted and expanded from a 12-session empirically supported CBCT intervention for genito-pelvic pain/penetration disorder, which is a sexual dysfunction associated with low sexual desire/arousal (Bergeron et al., 2021). The CBCT intervention for SIAD was informed by the Interpersonal Emotion Regulation Model of women’s sexual dysfunction (Rosen & Bergeron, 2019), which posits that interpersonal factors acting distally (i.e., predisposing aspects of the relationship that predate SIAD) and proximally (i.e., what occurs immediately surrounding sexual interactions) affect couples’ co-regulation of emotions and in turn impacts couples’ sexual and relationship adjustment. The treatment manual also focused on interpersonal factors relevant to SIAD and as identified in dyadic research (e.g., sexual motivation, sexual communication, relational self-expansion, and emotion co-regulation; Bockaj et al., 2019; Dubé et al., 2019; Hogue et al., 2019; Raposo et al., 2020; Rosen et al., 2019, 2020).

The goals of the CBCT intervention were to help couples (1) re-conceptualize low sexual desire/arousal as multidimensional and highlight how both partners affect and are affected by the SIAD symptoms, (2) modify those factors that are associated with low sexual desire/arousal to increase adaptive coping, facilitate sexual desire/arousal, and reduce sexual distress, (3) improve couple interactions related to sexuality via enhanced emotion regulation and communication skills, and (4) consolidate skills developed during the intervention. A detailed list of the session agendas and homework exercises covered during each of the 16 sessions of CBCT are included as an online supplementary file (Table S1) and the treatment manual is available from the authors upon request. Examples of the interventions include psychoeducation about sexual desire and sexual response as well as practice with communication and emotional awareness skills, managing chronic stress and unhelpful thinking styles, sensate focus exercises (Weiner & Avery-Clark, 2017), fostering self-determined (intrinsic) sexual motives, declining sexual activity in a more responsive way, and engaging in novel and exciting activities as a couple (i.e., relational self-expansion).

Study Therapists

The study had four therapists, two per site, who had PhD-level training in clinical psychology and sex therapy. Three of the therapists were in the final year of their doctoral training and one therapist was a postdoctoral fellow and registered psychologist (first author). The therapists received approximately 12 hours of training in the delivery of the treatment manual by the supervising psychologists (second and last study authors). Training included readings about CBCT as well as review and discussion of relevant video-recorded sessions from the RCT of CBCT for genito-pelvic pain/penetration disorder (Bergeron et al., 2021). Throughout the intervention, study therapists took part in weekly clinical supervision with the second or last author (depending on the site), who are both psychologists with advanced training in sex and couple therapy and developed the treatment manual with the first author.

Measures

The feasibility of administering the CBCT intervention was assessed in three ways: (1) The therapists’ overall adherence to the treatment manual during video-recorded sessions as well as therapists’ tracking for (2) completion of in-session exercises and (3) couples’ completion of homework exercises. Three independent raters (one for each site, and a third assessing both sites) viewed and coded a random sample (25%) of all video-recorded sessions for treatment manual adherence. The behavioral coding scheme contained seven items (session content, homework review, homework assignment, sexuality focus, dyadic factors, alliance/rapport, engagement with both couple members), which independent raters were trained to score on a scale from 0 (behavior not at all present) to 5 (behavior conforms exactly to the manual; Bergeron et al., 2021). Following each session, therapists coded the in-session interventions and couples’ homework as complete or incomplete. For an in-session intervention or homework exercise to be coded as complete, it must have been completed during the assigned session from the manual (i.e., homework or in-session interventions completed later were not coded as complete). We defined treatment nonadherence as completing less than half (50%), or a minority, of homework exercises (Corsini-Munt et al., 2014).

The acceptability of the CBCT intervention was assessed in four ways: (1) The overall dropout rate of the couples in the study, (2) couples’ overall attendance rates for the 16 sessions, (3) couples’ self-reported treatment satisfaction, and (4) couples’ self-reported satisfaction with virtual care. Participants self-reported their global treatment satisfaction on a scale from 0 (completely dissatisfied) to 10 (completely satisfied) immediately post-treatment and at 6-month follow-up. A question about participants’ satisfaction with completing couple therapy via virtual care (on Zoom) was added at 6-month follow-up and rated on the same scale from 0 (completely dissatisfied) to 10 (completely satisfied). Couples also listed the in-session or homework exercise(s) they found most helpful and least helpful for “improving the overall quality of your sex life” in an open text box on the post-treatment survey.

The dyadic sexual desire for a partner subscale (DSD-P; Moyano et al., 2017) of the Sexual Desire Inventory-2 (Spector et al., 1996) was used to assess partner-focused sexual desire in women with SIAD. This validated subscale includes two items about the frequency of partner-focused sexual thoughts (0–7 scale) and five items about the strength of sexual desire for sexual activity with a partner (0–8 scale) in the prior 4 weeks. Items are summed to calculate a subscale score that ranges from 0 to 54, with higher scores indicating greater sexual desire for a partner. Scores on the DSD-P have demonstrated good validity via positive correlations with sexual satisfaction (Moyano et al., 2017). Internal consistency for the DSD-P at pre-treatment was α = .70.

The Sexual Distress Scale-Revised (SDS-R) was used to assess sexual distress in both members of the couple (DeRogatis et al., 2008). This single-factor, 13-item measure assesses the frequency of negative and distressing emotions about an individual’s sexual relationship (DeRogatis et al., 2008). Although initially developed as a measure of female sexual distress (Female Sexual Distress Scale-Revised; DeRogatis et al., 2008), the measure has been validated in male samples as well (Santos-Iglesias et al., 2018). Participants rated how frequently they experienced distress (e.g., guilt, frustration, stress) about their sex lives in the prior 4 weeks, on a scale from 0 (never) to 4 (always). Items are summed to calculate a total score that ranges from 0 to 52, with higher scores indicating greater sexual distress. Scores on the SDS-R have demonstrated good validity, such that the SDS-R correlates positively with sexual bother and is weakly correlated with relationship quality (DeRogatis et al., 2008) and sexual attitudes (Santos-Iglesias et al., 2018), as expected. The internal consistency for the SDS-R at pre-treatment was α = .91 for women with SIAD and α = .88 for partners.

Pre-Registration of Secondary Outcomes

We collected data for secondary outcome measures of sexual problem distress, sexual communication, sexual satisfaction, relational intimacy, and relationship satisfaction and pre-registered a plan to assess for improvements from pre-treatment to post-treatment and pre-treatment to 6-month follow-up for these secondary outcomes. As per the guidelines for pilot and feasibility studies (Eldridge et al., 2016; Lancaster & Thabane, 2019), we present only the primary outcomes below. For transparency, the results related to secondary outcomes are available as an online supplementary file.

Data Analysis

The study pre-registration, syntax, and output can be found on the Open Science Framework (see data availability statement). Descriptive statistics for sociodemographic information, feasibility, and acceptability were conducted in IBM SPSS Statistics (Version 28). For the video recordings, we computed the percentage of time that therapists adhered to the treatment manual (i.e., rated 4 or 5 on behavioral coding scheme) and mean prevalence- and bias-adjusted kappa for ordinal data (PABAK-OS)³ for interrater reliability of the video raters. For completion of in-session and homework exercises as well as dropout and attendance rates, we computed percentages based on the number of completed exercises or sessions divided by the number of planned exercises or sessions.

To assess for potential improvements in dyadic sexual desire and sexual distress following the CBCT intervention, data were analyzed using multilevel models with maximum-likelihood (ML) estimation of parameters in Mplus 8 (Version 8.6; Muthén & Muthén, 1998–2017). We estimated two multilevel models, with one outcome measure included per model. Analyses were conducted using the intent-to-treat principle whereby all couples who began the treatment were included in the analyses for dyadic sexual desire and sexual distress. The multilevel model for sexual distress was guided by the Actor-Partner Interdependence Model to account for the interdependence of couple members’ data (Kenny et al., 2006). We pre-registered a plan to interpret findings primarily based on effect sizes, rather than statistical significance (though we report on both), to address potential effects of a small sample size on statistical power. Because this is the first study to our knowledge that evaluated a couple-based sex therapy intervention for SIAD, there are no published studies against which to compare effect sizes. As such, we pre-registered a plan to use Cohen’s d benchmark values of 0.20 (small), 0.50 (medium), and 0.80 (large) to interpret effect sizes (Cohen, 1988).

Results

Treatment Manual Adherence and Exercise Completion

The video coders exhibited substantial agreement with a mean PABAK-OS coefficient of 0.77 across the seven behavioral coding items (range = 0.57 to 0.90). Based on the video-recorded sessions, therapists adhered to the treatment manual 96.8% of the time. In terms of in-session and homework exercise completion, therapists recorded that couples completed an average of 91.0% of the 14 planned in-session exercises (range = 76.9% to 100%) as well as 82.0% of the 23 planned homework exercises (range = 52.2% to 100%).

Attendance Rates and Treatment Satisfaction

Two couples did not complete the full treatment due to study withdrawal after 10 sessions and relationship dissolution after 14 sessions, resulting in an overall study attrition rate of 10.5%. The remaining 17 couples completed all 16 sessions. The overall attendance rate for the sample of 19 couples was 97.4% (range = 62.5% to 100%).

Immediately post-treatment, global treatment satisfaction (rated out of 10) was M = 7.39 (SD = 2.25) for women with SIAD and M = 7.33 (SD = 2.11) for partners. At 6-month follow-up, global treatment satisfaction was M = 6.50 (SD = 3.02) for women with SIAD and M = 6.94 (SD = 2.34) for partners. Mean satisfaction with completing couple therapy via virtual care (on Zoom) was M = 8.00 (SD = 2.54) for women with SIAD and M = 7.72 (SD = 2.32) for partners at 6-month follow-up; satisfaction with virtual care was not assessed in the post-treatment survey.

Table 2 presents the frequencies for participants’ reports of the therapy exercise(s) they found most helpful and least helpful for improving the overall quality of their sex life. To facilitate comparisons of the perceived helpfulness of different therapy exercises, we excluded participants who answered that all the exercises were helpful or unhelpful, or that none of the exercises were helpful or unhelpful. A total of 32 individuals (of 38) listed a range of one to eight exercises as being most helpful, with most participants identifying only one exercise in their response. The modal response for the most helpful therapy exercise was sensate focus exercises (46.9% of 32 respondents). In terms of unhelpful exercises, 18 individuals (of 38) identified a range of one to four exercises, with a single answer being the most common response. The modal response for the least helpful exercise was breathing exercises (27.8% of 18 respondents).

Table 2. Frequencies of participants’ responses for most and least helpful therapy exercises (n = 32 individuals).

In-session and/or homework exercise	Most helpful n (%)		Least helpful n (%)
	SIAD n = 16	Partners n = 16	SIAD n = 9	Partners n = 9
SIAD readings	0	1	1	1
Biopsychosocial and interpersonal model	1	0	0	0
CBT and CBCT models (5- and 9-part models)	1	1	2 (22.2%)	0
Communication exercises	6 (37.5%)	3 (18.8%)	0	0
Managing chronic stress	0	0	0	0
Breathing exercises (relaxation/tantric for two)	1	0	3 (33.3%)	2 (22.2%)
Circular model of sexual response	3 (18.8%)	1	0	0
Sexual menu	4 (25.0%)	2	2 (22.2%)	2 (22.2%)
Unhelpful thinking styles/thought record	2	2	1	0
Sensate focus	8 (50.0%)	7 (43.8%)	1	1
Emotional awareness during sexual communication	1	1	0	1
Dual control model (accelerators and brakes)	3 (18.8%)	0	0	0
Sexual motivation (intrinsic and extrinsic motives)	2	0	0	0
Declining sex/being declined for sex	1	0	2 (22.2%)	1
Self-expansion activities	4 (25.0%)	2	0	0
Beliefs about sex and sexual desire/arousal	0	1	0	1
Progress letter	0	0	0	0

Individuals could indicate multiple responses for the most helpful and least helpful therapy exercises, so the frequencies sum to greater than the number of participants (n) for each column. The modal responses are in bold. The percentages for frequencies below 15% are not reported in parentheses.

Women’s Dyadic Sexual Desire and Couples’ Sexual Distress

The means and standard deviations for dyadic sexual desire and sexual distress at each time of assessment are presented in Table 3 and the multilevel models are presented in Table 4. As expected, women with SIAD reported a moderate to large increase in dyadic sexual desire for their partner from pre-treatment to post-treatment (d = 0.73) and a large increase from pre-treatment to 6-month follow-up (d = 0.88).

Table 3. Descriptive statistics for outcomes by time of assessment (n = 19 couples).

	SIAD			Partners
	T1 M (SD)	T2 M (SD)	T3 M (SD)	T1 M (SD)	T2 M (SD)	T3 M (SD)
Dyadic sexual desire (DSD-P)	11.63 (7.08)	16.89 (7.89)	17.83 (8.02)	-	-	-
Sexual distress (SDS-R)	29.47 (9.00)	20.39 (9.00)	19.33 (8.21)	21.68 (8.84)	16.94 (10.83)	19.06 (10.76)

T1 = pre-treatment, T2 = post-treatment, T3 = 6-month follow-up. M = mean, SD = standard deviation.

Table 4. Multilevel models (n = 19 couples).

	SIAD				Partner
	b (SE)	p	d	95% CI	b (SE)	p	d	95% CI
Dyadic sexual desire (DSD-P)
Intercept	11.81 (1.58)	<.001		8.71, 14.91	–	–	–	–
Time (T1-T2)	5.20 (1.67)	.002	0.73	1.92, 8.47	–	–	–	–
Time (T1-T3)	6.22 (1.71)	<.001	0.88	2.86, 9.58	–	–	–	–
Sexual distress (SDS-R)
Intercept	29.23 (1.96)	<.001		25.38, 33.07	21.43 (2.10)	<.001		17.32, 25.53
Time (T1-T2)	-8.40 (2.43)	.001	−0.93	-13.16, −3.63	-4.79 (1.52)	.002	−0.54	-7.78, −1.81
Time (T1-T3)	-9.88 (2.31)	<.001	−1.10	-14.41, −5.35	-2.73 (1.33)	.04	−0.31	-5.33, −0.14

T1 = pre-treatment, T2 = post-treatment, T3 = 6-month follow-up.

As expected, women with SIAD reported a large decrease in sexual distress from pre-treatment to post-treatment (d = −0.93) and pre-treatment to 6-month follow-up (d = −1.10). Likewise, partners reported a moderate decrease in sexual distress from pre-treatment to post-treatment (d = −0.54) and a small decrease in sexual distress from pre-treatment to 6-month follow-up (d = −0.31).

Discussion

In this study, we developed and tested a 16-session CBCT intervention for SIAD. As expected, we found that the intervention was feasible to administer, such that therapists were highly adherent to the treatment manual and both the therapists and couples completed a substantial majority of the planned in-session and homework exercises. We also found that the CBCT intervention was acceptable to couples, based on low overall attrition rates as well as high session attendance rates, ratings of global treatment satisfaction, and ratings of satisfaction with virtual care. Additionally, we found that the CBCT intervention produced moderate to large pre-treatment to post-treatment improvements in women’s dyadic sexual desire for their partner and sexual distress for both members of the couple. Overall, findings from this study confirm that this couple-based sex therapy intervention grounded in theory and dyadic research evidence is feasible and merits full testing in an RCT.

Establishing the feasibility and acceptability of CBCT for SIAD is an important step in testing the intervention before considerable resources are invested in an RCT. Despite having an ambitious number of in-session and homework exercises, the therapists and couples exhibited high levels of treatment adherence and homework completion. The 82.0% homework completion rate was well above the 50% criterion we set to represent the majority of homework exercises and similarly high compared to other psychological intervention studies for treating individuals’ distressing low sexual desire (Brotto et al., 2021). In line with meta-analytic findings that homework assignments enhance cognitive-behavioral therapy outcomes (Kazantzis et al., 2010, 2018), the high level of homework adherence in the current study may have contributed to the changes in clinical outcomes. Due to the small sample size in this study, we did not examine the association between homework completion and sexual outcomes post-treatment, but this is an important empirical question for research on individual and coupled-based sex therapy interventions, particularly because many sex therapy exercises must be completed outside of sessions (e.g., couple-oriented touching exercises).

Couples in the sample attended a substantial majority (97.4%) of the planned sessions, which served as a proxy of acceptability. Women with SIAD and their partners reported a relatively high level of treatment satisfaction (~7/10). They also reported feeling satisfied with completing CBCT via virtual care (~8/10), which is consistent with findings for overall trends in psychological intervention research (Appleton et al., 2021; Petkari et al., 2023). Couples in our sample listed a range of in-session and homework exercises they found most and least helpful for improving the overall quality of their sex lives. The variability in responses likely reflects what individuals and couples found most resonant to their personal experience. In clinical practice, CBCT for SIAD could be tailored to couples’ unique experiences with managing sexual desire in their relationship, which distinguishes this intervention from group-based couple therapy protocols. For example, clinicians could ask for regular feedback about what exercises are most helpful and tailor the treatment plan accordingly. For both women with SIAD and their partners, the modal response for the most helpful therapy intervention was sensate focus. This empirically-based touching exercise for couples was created by Masters and Johnson (1970) and has been a mainstay in sex therapy practice ever since (Weiner & Avery-Clark, 2014). The principles of sensate focus are to re-introduce touch in a non-demanding way and teach individuals to manage cognitive distractions that arise while being touched by their partner (Linschoten et al., 2016; Weiner & Avery-Clark, 2014, 2017). As such, sensate focus integrates cognitive and behavioral strategies into one homework exercise for couples.

The improvements in dyadic sexual desire and sexual distress following CBCT are consistent with findings from psychological intervention research for women with distressing low desire and extend benefits to partners. We found moderate to large effects for women’s dyadic sexual desire for their partner immediately post-treatment and at 6-month follow-up, which is consistent with meta-analytic findings for group-based couple therapies and mindfulness-based therapies for HSDD (Banbury et al., 2021; Frühauf et al., 2013; Günzler & Berner, 2012). Furthermore, we found large improvements in sexual distress for women with SIAD and moderate improvements for partners immediately post-treatment. The therapy and homework exercises in the CBCT intervention were directly modeled on interpersonal factors shown to be associated with sexual desire, satisfaction, and distress among couples coping with SIAD, including sexual motivation, sexual communication, partner responses to low sexual desire, relational self-expansion, and emotion regulation (Bockaj et al., 2019; Dubé et al., 2019; Hogue et al., 2019; Raposo et al., 2020; Rosen et al., 2019, 2020). These improvements in sexual distress highlight that the treatment was especially helpful in relieving the emotional burden of SIAD, which is significant given that several studies have documented the shame, guilt, frustration, and sadness experienced by those affected by distressing low sexual desire (Dubé et al., 2019; Frost & Donovan, 2021; Kingsberg, 2014).

Strengths, Limitations, and Future Research

Sexual interest/arousal disorder is the most common and relational sexual dysfunction among women, yet there are relatively few empirically supported treatment options, and none that are couple based. A key strength of this study is that we developed and tested a treatment manual, rather than testing unstructured couple therapy. The use of a treatment manual is important because the intervention can then be tested in a RCT. This study also included a rigorous design with treatment adherence coding via video-recorded therapy sessions to directly assess the feasibility of administering the intervention as written in the treatment manual. Finally, we employed an intent-to-treat approach to limit bias and multilevel modeling guided by the Actor-Partner Interdependence Model to account for the non-independence of dyadic data (Kenny et al., 2006).

This study represents a first step in developing and testing a novel CBCT intervention for SIAD. As such, there are important caveats to consider when interpreting the results. By design, this study did not have a control group, so we cannot assess whether the observed changes in dyadic sexual desire and sexual distress occurred due to the passage of time or treatment expectancy, rather than the effects of the treatment. Also, the sample size for the study was small and as a result, the multilevel models may be more susceptible to type I error than for larger samples (Bell et al., 2014; Hox & McNeish, 2020). The current study also had some limitations that impact the generalizability of the results. Despite study criteria that were inclusive of women and non-binary people with SIAD as well as partners of any gender/sex, the study sample was homogenous. All participants with SIAD identified as cisgender women and 94.7% of the sample were in mixed-gender/sex dyads. We recruited participants from a psychology private practice or self-referral following a news article about couple-based sex therapy, neither of which involved targeted recruitment of people with minoritized genders, sexual orientations, or other underrepresented groups (e.g., by race/ethnicity, ability, or socioeconomic status). As such, the results of the current study may not generalize to non-binary people with SIAD or same-gender/sex couples coping with SIAD. However, the treatment manual was developed to be inclusive of diverse genders/sex/ualities, so testing the efficacy of CBCT for SIAD in more diverse samples is possible. The sample was also highly educated, and most couples reported a higher income than the median Canadian household income. Since sex and couple therapy are often provided in private practice rather than public health settings, finances are a common barrier to accessing treatment. Accordingly, several studies have demonstrated the feasibility of online, module-based psychological interventions for SIAD as a less expensive treatment option, circumventing the need for access to a trained clinician (Brotto et al., 2022; Stephenson et al., 2021); however, full-scale efficacy trials of these interventions are still needed.

The next step for this research is to test the efficacy of the CBCT intervention for SIAD in an RCT. Conducting an RCT with a larger sample will enable us to compare CBCT to a control group as well as examine potential moderators and mediators of treatment outcome, such as couples’ improved emotion regulation as proposed in the Interpersonal Emotion Regulation Model of women’s sexual dysfunction (Rosen & Bergeron, 2019). Furthermore, targeted recruitment for the RCT will support the inclusion of a more diverse sample of couples in terms of dyad type, race/ethnicity, and socioeconomic status. Finally, we will aim to recruit a more gender inclusive sample of individuals with SIAD, including all people with distressing low sexual desire/arousal for whom being a woman is at least part of their identity.

Conclusion

This study established the feasibility a novel couple-based sex therapy invention for SIAD. For women with SIAD, we found that the CBCT intervention produced moderate to large improvements in the key symptoms of low dyadic sexual desire for their partner and sexual distress that were observed 6 months later. Partners also reported small to moderate improvements in sexual distress. The CBCT intervention is an evidence-based treatment for SIAD that directly addresses the interpersonal nature of distressing low sexual desire. A randomized clinical trial is needed to evaluate the efficacy of CBCT for SIAD.

Acknowledgments

We are grateful to the couples who participated in this study for their contributions to our research. Thank you to the study therapists, Véronique Charbonneau-Lefebvre, Alexa Larouche-Wilson, and Meghan Rossi, as well as research assistants and staff, Marcus Cormier, Mylène Desrosiers, Justin Dubé, Gillian Hyslop, Maude Massé-Pfister, and Maude Roy, who supported data collection. Thanks also to Gabrielle Marcotte and Marie-Pier Vaillancourt-Morel for providing statistical consultation. A version of the findings reported in this paper was presented at the 2023 meeting of the International Academy of Sex Research in Montréal, QC, Canada.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The dataset that supports the findings of this study is available on request from the authors. The dataset is not publicly available due to the small sample size and risk that participants could identify their own data and as a result, their partner’s responses. However, the pre-registration, syntax, and output for this study are available on the Open Science Framework (OSF) at https://osf.io/5c8kv/.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00224499.2024.2333477.

Additional information

Funding

This work was supported by a Dr. Harold B. Atlee Research Endowment Award from Dalhousie University awarded to Katrina Bouchard and a Project Grant from the IWK Health Centre [# 1026820] awarded to Natalie Rosen. Katrina Bouchard was supported by an IWK Postdoctoral Fellowship Award, Sophie Bergeron was supported by a Tier I Canada Research Chair in Intimate Relationships and Sexual Well-being, and Natalie Rosen was supported by a Professorship from the Dalhousie Medical Research Foundation and Department of Obstetrics and Gynaecology.

Notes

¹ The DSM-5 diagnosis is female sexual interest/arousal disorder. We have dropped the “female” from this label in our research to be inclusive of trans women and non-binary individuals who may otherwise meet the diagnostic criteria.

² The study criteria were inclusive of all individuals assigned female at birth with low sexual desire/arousal (e.g., woman, non-binary person); however, all participants with low sexual desire/arousal who expressed interest in the study identified as women.

³ We pre-registered a plan to assess interrater reliability using weighted kappa; however, the video raters recorded high levels of adherence to the manual (see Results) producing paradoxical weighted kappas (e.g., negative, near zero values, despite over 90% observed agreement between raters). As such, we calculated the PABAK-OS, which addresses conflicts between kappa and percent agreement by accounting for prevalence and bias in ratings on ordinal scales (Nurjannah & Siwi, 2017). We calculated PABAK-OS coefficients using a web-based calculator (Vannest et al., 2016).