Cognitive-Behavioural Couple Therapy for Sexual Interest/Arousal Disorder

As a core symptom of SIAD, partner-focused dyadic sexual desire will be assessed using the 7-item subscale of the Sexual Desire Inventory. This subscale measures interest in sexual activity, including one's thoughts on approaching or being responsive to sexual stimuli with a partner, in a Likert-type response format (e.g., 1 = not at all, 7 = a lot). Higher scores indicate greater partner-focused dyadic sexual desire. For the in-treatment surveys, a shorter version of the Sexual Desire Inventory-2, including two items, will be used to minimize participant burden. This version has been used in prior studies and showed adequate psychometric properties.

As a core symptom of SIAD, sexual distress will be measured with the 5-item Sexual Distress Scale-SF (SDS-SF). Using a 5-point Likert scale, participants rate how frequently (e.g., 1 = never, to 5 = always) they experience an emotion or sexuality related problem. These items showed greatest function at the item level, greatest contribution to the scale's reliability, and good capacity to discriminate between participants with distressing sexual problems and those without distressing sexual problems. This measure is valid regardless of whether participants are sexually active. For the in-treatment surveys, the three-item version of the SDS-SF will be used to minimize participant burden. It has been used in previous studies and showed adequate psychometric properties.

The Global Measure of Sexual Satisfaction (GMSEX) assesses overall sexual satisfaction. This scale consists of five items assessing a subjective evaluation of the sexual relationship on five 7-point dimensions: good vs. bad, pleasant vs. unpleasant, positive vs. negative, satisfying vs. unsatisfying, and valuable vs. worthless. Ratings are summed such that possible scores range from 5 to 35, with higher scores indicating greater sexual satisfaction. For the in-treatment surveys, a one-item measure of sexual satisfaction will be used to minimize participant burden. Previously used by our team and showing adequate psychometric properties, the single-item measure asks participants to rate, on a scale of 1 (Very dissatisfied) to 5 (Very satisfied), their answer to the following question: "Since the last survey, how satisfied have you been with your relationship with your partner?".

It will be assessed with the 16-item Couples Satisfaction Index. Participants will rate their relationship on a number of factors. For example, participants will indicate how happy they are with their relationship, how frequently they disagree with their partner, and how they feel their relationship compares to others. For the in-treatment surveys, participants will fill the four-item shorter version.

Intimacy will be measured using 9 items on a 7-point scale (1 = not at all, 7 = a lot) where participants rate in general how much they perceived their partner to be responsive, self- and partner-disclosure of private thoughts and feelings and the level of overall intimacy they feel in their relationship.

It will be measured using the Hospital Anxiety and Depression Scale. This 14-item measure includes two subscales: depression (seven items) and anxiety (seven items). Using a time reference of the last 7 days, participants score each item on a scale from 0 (e.g., Not at all) to 3 (e.g., Most of the time), with higher scores indicating greater severity of symptoms. This measure has been shown to have good reliability and validity.

Post-treatment satisfaction will be measured using 3 items asking participants to (a) rate on a scale from 0 to 10 their global satisfaction towards the treatment received, (b) whether there is anything else they would like to share about their experience in this treatment, (c) their satisfaction with completing couple therapy via virtual care (on Zoom) on a scale from 0 to 10.

Global ratings of improvement will be measured using 3 items assessing on a scale of 0 (deterioration) to 5 (complete recovery) (a) if there has been an improvement in their sexual desire and/or arousal difficulties following the treatment, (b) if there has been an improvement in distress (negative emotions) about their sex life following the treatment, (c) if there has been an improvement in the overall quality of their sex life following the treatment.