JMIR FORMATIVE RESEARCH

Saito et al

Original Paper

Differences in Psychological Inflexibility Among Men With Erectile
Dysfunction Younger and Older Than 40 Years: Web-Based
Cross-Sectional Study
Junichi Saito1, PhD; Hiroaki Kumano2, MD, PhD; Mohammad Ghazizadeh3, MD, PhD; Chigusa Shimokawa3, MA;
Hideki Tanemura3, MBA
1

Comprehensive Research Organization, Waseda University, Saitama, Japan

2

Faculty of Human Sciences, Waseda University, Saitama, Japan

3

Logos Science Corp, Tokyo, Japan

Corresponding Author:
Junichi Saito, PhD
Comprehensive Research Organization
Waseda University
2-579-15, Mikajima, Tokorozawa
Saitama, 359-1192
Japan
Phone: 81 429498113
Email: tekuteke@aoni.waseda.jp

Abstract
Background: Psychological inflexibility is a core concept of acceptance and commitment therapy (ACT), which is acomprehensive, transdiagnostic interpretation of mental health symptoms. Erectile dysfunction (ED) is a condition that affects
male sexual performance, involving the inability to achieve and maintain a penile erection sufficient for satisfactory sexual
activity. Psychosocial factors primarily influence ED in men younger than 40 years, whereas biological factors are more likely
to be the underlying cause in older men.
Objective: This web-based cross-sectional study examined differences in depression, anxiety, and psychological inflexibility
among men with ED younger and older than 40 years in a Japanese population.
Methods: We used a web-based survey to gather data from various community samples. ED was assessed by the International
Index of Erectile Function‐5 (IIEF-5) questionnaire, while depression, anxiety, and psychological inflexibility were evaluatedby the Patient Health Questionnaire-9 (PHQ-9), General Anxiety Disorder-7 (GAD-7), Acceptance and Action Questionnaire-II(AAQ-II), Cognitive Fusion Questionnaire (CFQ), and Valuing Questionnaire–Obstacle Subscale (VQ-OB) questionnaires. The
chi‐square test estimated the scores of PHQ-9 and GAD-7 among men with ED, comparing those younger than 40 years andthose older than 40 years. Additionally, a two-way ANOVA was conducted with ED severity and age group as independent
variables, assessing psychological inflexibility.
Results: Valid responses from 643 individuals (mean age 36.19, SD 7.54 years) were obtained. Of these, 422 were younger
than 40 years (mean age 31.76, SD 5.00 years), and 221 were older than 40 years (mean age 44.67, SD 2.88 years). There was astatistical difference in the prevalence of depression as judged by PHQ≥10 between men with ED younger and older than 40
years (P<.001). On the other hand, there was no difference in the prevalence of anxiety as judged by GAD≥10 (P=.12). The
two-way ANOVA revealed that the interactions for CFQ (P=.04) and VQ-OB (P=.01) were significant. The simple main effect
was that men with ED younger than 40 years had significantly higher CFQ (P=.01; d=0.62) and VQ-OB (P<.001; d=0.87) scorescompared to those older than 40 years in moderate ED and severe ED. Additionally, it was found that men younger than 40 years
with moderate to severe ED had significantly higher CFQ (P=.01; d=0.42) and VQ-OB (P=.02; d=0.38) scores compared to men
younger than 40 years without ED. On the other hand, no interaction was found for AAQ-II (P=.16) scores.
Conclusions: To the best of our knowledge, this web-based cross-sectional study is the first to examine the relationship between
psychological inflexibility and ED. We conclude that men with moderate and severe ED younger than 40 years have higher
psychological inflexibility and might be eligible for ACT.

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Saito et al(JMIR Form Res 2024;8:e45998) doi: 10.2196/45998
KEYWORDS
erectile dysfunction; acceptance and commitment therapy; psychological inflexibility; depression; anxiety; men; cross-sectional
study; psychological; utility; psychosocial; men; therapy; impotence; erection

Introduction
The efficacy of acceptance and commitment therapy (ACT) has
been evaluated in numerous randomized controlled studies
exploring various targeted conditions [1]. There is supporting
evidence for ACT across various physical illnesses (eg, chronic
pain [2], diabetes [3], epilepsy [4], cancer [5], and irritablebowel syndrome [6]). Many of these studies use atransdiagnostic method to analyze psychological issues within
individual health conditions. Psychological inflexibility is acore concept of ACT, which is a comprehensive, transdiagnostic
interpretation of mental health symptoms [7]. Psychologicalinflexibility highlights two interrelated processes: cognitive
fusion and experiential avoidance. Cognitive fusion represents
the phenomenon by which individuals are influenced by theliteral meaning of their thoughts instead of viewing them astransient internal states [8]. Experiential avoidance represents
an attempt or desire to suppress unwanted internal experiences,such as emotions, thoughts, memories, and bodily sensations[9]. These processes are obstacles to one’s valued living
activities, decreasing well-being [10].
Erectile dysfunction (ED) is a condition that affects male sexual
performance, involving the inability to achieve and maintain apenile erection sufficient for satisfactory sexual activity [11].
Several reviews and clinical guidelines are available for ED.
However, many of these approaches to assessing and treating
ED purely from a medical perspective seldom address thepsychosocial components of ED [12]. Pharmacological treatment
alone does not respond to all the concurrent factors of ED,
including anxiety, loss of self-confidence, depressed mood,difficulties in a couple’s communication, relationship disputes,
or a partner’s sexual problems [13]. Recent systematic reviews
have shown that combining phosphodiesterase-5 inhibitors withpsychological treatment exhibits significant potential for treating
ED [14].
There is a widespread assumption that psychosocial factors
primarily influence ED in men younger than 40 years, whereas
biological factors are more likely to be the underlying cause of
ED in older men. Moore et al [15] showed different symptom
patterns among patients with ED according to age groups. They
reported that younger men had comparatively more significant
depressive symptoms, with lower relationship satisfaction, morenegative reactions from partners, and lower job satisfaction.
Given these findings, it is possible that people younger than 40
years are more psychologically inflexible than those older than
40 years and that ACT is more effective for them. However,studies on ACT for ED remain limited, with only a few
identified. Therefore, this cross-sectional study used assessments
to evaluate depression, anxiety, and psychological inflexibility
in men younger and older than 40 years. However, it is wellknown that ED prevalence varies across geographical groups[16,17]; therefore, it is essential to research ED etiology
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according to different racial, cultural, religious, andsocioeconomic backgrounds. There might be many potential
patients with ED in Japan, so we conducted a web-based survey
for this study.

Methods
Participants
To gather data from a wide range of community samples, weused a web-based survey, conducted with the assistance of amarketing research service provider (Rakuten Insight, Inc) inJapan. Based on the International Index of Erectile Function‐5(IIEF-5) cutoff point [18], participants of all severities wererecruited to include a certain percentage of patients of all ages.
All enrolled participants followed the following criteria: (1)male; (2) aged 20 to 50 years; and (3) married or living with afixed sexual partner for more than 6 months. The exclusion
criteria were as follows: (1) sexual dysfunction caused by
Peyronie disease or other organic lesions of the external
genitalia; (2) prostate cancer, hypertensive disease, cardiac
disease, cerebrovascular disease, chronic kidney disease, anddiabetes; and (3) a history of sertraline or other medicines that
may influence erection and psychological symptoms.
Participants were first instructed that this survey would be
administered anonymously, and their responses were notcompulsory. Then, those participants who agreed to participate
in this research responded to the surveys. Participants were
given points to exchange for items within the survey company’ssystem as a reward.

Ethical Considerations
This study was approved by the Waseda University Academic
Research Ethical Review Committee (2019-363). The study
protocol followed the guidelines for epidemiological studies inaccordance with the Declaration of Helsinki.

Measurements
International Index of Erectile Function-5 (IIEF-5)
The Japanese version of IIEF-5 is a 5-item self-reportquestionnaire designed to measure erectile function [18]. Items
are rated on a 5-point Likert-type scale, ranging from 1 to 5.
The total score can range from 5 to 25, with high scores meaninghigh erectile function. Based on the original validation studies,
the total score can then be interpreted as suggesting “no ED”(22-25), “mild ED” (17-21), “mild-to-moderate ED” (12-16),“moderate ED” (8-11), and “severe ED” (5-7).

Patient Health Questionnaire-9 (PHQ-9)
The Japanese version of the Patient Health Questionnaire-9(PHQ-9) is a 9-item self-report questionnaire designed tomeasure depression [19]. Items are rated on a 4-point Likert-type
scale, ranging from 0 to 3. The total score can range from 0 to
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Saito et al27, with high scores meaning high depression. Based on theoriginal validation studies, the total score can then be interpreted
as suggesting no depression (0-4), mild depression (5-9),
moderate depression (10-14), moderately severe depression(15-19), or severe depression (20-27). A cutoff score of 10 issuggested as indicating a possible diagnosis of depressive
disorder.

Valuing Questionnaire–Obstacle Subscale (VQ-OB)

Generalized Anxiety Disorder-7 (GAD-7)

Statistical Analysis

The Japanese version of the Generalized Anxiety Disorder-7(GAD-7) questionnaire is a 7-item self-report questionnaire
designed to measure generalized anxiety disorder [20]. Items
are rated on a 4-point Likert-type scale, ranging from 0 to 3.
The total score can range from 0 to 21, with high scores meaninghigh anxiety. Based on the original validation studies, the total
score can then be interpreted as suggesting no anxiety (0-4),
mild anxiety (5-9), moderate anxiety (10-14), or severe anxiety(14-21). A cutoff score of 10 is suggested as indicating a
possible diagnosis of generalized anxiety disorder.

We used mean (SD) values to describe numerical data andcounts and percentages to describe categorical data. The
chi‐square tests estimated categorical data, and numerical data
were estimated by t tests. A two-way ANOVA test was used toassess the differences in men with ED aged younger and older
than 40 years regarding psychological inflexibility and theinteraction between them. Post hoc tests were conducted using
the Holm method to control for type I errors. Cohen d index
was calculated as effect sizes, serving as standardized indicators
unaffected by sample sizes. All tests were 2-tailed, and astatistical difference was assumed when the P value was <.05.
All statistical analyses were conducted through IBM SPSS
Statistics (version 25.0; IBM Corp).

Acceptance and Action Questionnaire-II (AAQ-II)
The Japanese version of the Acceptance and Action
Questionnaire-II (AAQ-II) is a 7-item self-report questionnaire
designed to measure experiential avoidance [21]. Items are rated
on a 7-point Likert-type scale, ranging from 1 to 7. The total
score can range from 7 to 49, with high scores meaning highexperiential avoidance.

Cognitive Fusion Questionnaire (CFQ)The Japanese version of the Cognitive Fusion Questionnaire(CFQ) is a 7-item self-report questionnaire designed to measurecognitive fusion [22]. Items are rated on a 7-point Likert-type
scale, ranging from 1 to 7. The total score can range from 7 to49, with high scores meaning high cognitive fusion.

The Japanese version of the Valuing Questionnaire–Obstacle
Subscale (VQ-OB) is a 5-item self-report questionnaire designed
to measure obstruction of valued living [23]. Items are rated on
a 7-point Likert-type scale, ranging from 0 to 6. The total score
can range from 0 to 30, with high scores meaning highobstruction of valued living.

Results
We obtained valid responses from 643 individuals (mean age
36.19, SD 7.54 years). Of these, 422 were younger than 40 years(mean age 31.76, SD 5.00 years), and 221 were older than 40
years (mean age 44.67, SD 2.88 years). Table 1 shows thedemographic characteristics of participants by age difference.
No statistical difference was found in ED severity,
phosphodiesterase-5 inhibitors use, and marriage status between
men with ED younger and older than 40 years.

Table 1. Demographic characteristics of men with erectile dysfunction (ED) younger and older than 40 years.
Characteristics<40 years of age (n=422)≥40 years of age (n=221)

P valueAge (years), mean (SD)31.76 (5.00)

44.67 (2.88)<.001

Marital status, n (%).44

Single77 (18.25)

35 (15.84)

Married345 (81.75)

186 (84.16)

4.87 (3.90)

10.43 (7.53)

Duration of marriage (years), mean (SD)IIEF-5a severity, n (%)

.84

No ED

84 (19.91)

49 (22.17)

Mild to mild-to-moderate ED

226 (53.55)

112 (50.68)

Moderate to severe ED

112 (26.54)

60 (27.15)

b.63

PDE-5 use, n (%)

a

<.001

Not using337 (79.86)

180 (81.45)

Using

85 (20.14)

41 (18.55)

IIEF-5: International Index of Erectile Function‐5.

b

PDE-5: phosphodiesterase-5 inhibitor.

The prevalence of depression as judged by PHQ≥10 among
men younger than 40 years was 39.81% (168/422), and it washttps://formative.jmir.org/2024/1/e45998

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24.89% (55/221) among those older than 40 years. There wasa statistical difference in the prevalence of depression between
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Saito et al

the two groups (P<.001). In addition, the prevalence of anxiety,as judged by GAD≥10, was 27.25% (115/422) among men
younger than 40 years, and it was 21.72% (48/221) among thoseolder than 40 years. There was no difference in the prevalenceof anxiety between men with ED in the two age groups (P=.12).
Table 2 illustrates these results.

Table 2. Prevalence of depression and anxiety among men with erectile dysfunction younger and older than 40 years.
Questionnaires and characteristics<40 years of age (n=422)≥40 years of age (n=221)

PHQ-9a<.001

No depression or mild depression (PHQ9<10), n (%)

254 (60.19)

166 (75.11)

Prevalence of depression (PHQ-9≥10), n (%) 168 (39.81)

55 (24.89)

GAD-7ba

P value.13

No anxiety or mild anxiety (GAD-7<10), n(%)

307 (72.75)

173 (78.52)

Prevalence of anxiety (GAD-7≥10), n (%)

115 (27.25)

48 (21.72)

PHQ-9: Patient Health Questionnaire-9.

b

GAD-7: Generalized Anxiety Disorder-7.

The two-way ANOVA was performed with ED severity andage (<40 or >40 years) as independent variables and the scoresof AAQ, CFQ, and VQ-OB as dependent variables. The results
showed no significant differences in AAQ-II (P=.14), CFQ(P=.08), and VQ-OB (P=.30) scores attributed to ED severity.
Moreover, no difference in ED severity or psychologicalinflexibility depending on the duration of the marriage wasfound. On the other hand, there were significant differences inthe scores of CFQ (P=.04) and VQ-OB (P=.004) attributed toage. As the interactions were significant for CFQ (P=.04) and

VQ-OB (P=.01) scores, the simple main effect was examined.
It was found that men with ED younger than 40 years had
significantly higher CFQ (P=.01; d=0.62) and VQ-OB (P<.001;
d=0.87) scores compared to those older than 40 years, in casesof moderate and severe ED. Additionally, it was found that men
with moderate to severe ED younger than 40 years had
significantly higher CFQ (P=.01; d=0.42) and VQ-OB (P=.02;
d=0.38) scores compared to men with no ED younger than 40
years. These results are illustrated in Table 3 and Figures 1 and2.

Table 3. Two-way ANOVA results of the influence of erectile dysfunction (ED) severity, age, and interaction on psychological inflexibility.
Parameters and factors

Sum of squares

Mean squares

F test (df)

P value

ED severity

281.60140.801.91 (2,637)

.14

Age

204.74204.742.78 (1,637).10

ED severity × age

267.27133.641.81 (2,637).16

ED severity

433.63216.822.49 (2,637)

.08

Age

348.12348.12

3.99 (1,637).04

ED severity × age

534.92267.463.07 (2,637).04

ED severity

74.56

37.28

1.19 (2,637)

.30

Age

263.36263.368.38 (1,637).004

ED severity × age

250.82125.41

3.99 (2,637).01

AAQ-II

CFQab

VQ-OBca

AAQ-II: Acceptance and Action Questionnaire-II.

b

CFQ: Cognitive Fusion Questionnaire.

c

VQ-OB: Valuing Questionnaire–Obstacle Subscale.

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Figure 1. Results of the two-way ANOVA and the simple main effect of the Cognitive Fusion Questionnaire (CFQ). ED: erectile dysfunction. P=.01
for "a," "b," and "c".

Figure 2. Results of the two-way ANOVA and the simple main effect of the Valuing Questionnaire–Obstacle Subscale (VQ-OB). ED: erectile
dysfunction. P<.001 for "a" and P=.02 for "b".

Principal Findings

the average age of the participants was 44.67 (SD 2.88) years
in men older than 40 years; the population was assumed to havemostly mild-to-moderate organic ED.

This cross-sectional study evaluated depression, anxiety, andpsychological inflexibility in men younger and older than 40
years with ED. There was no statistical difference indemographic characteristics between the two groups. The
average age of the participants was 31.76 (SD 5.00) years inmen younger than 40 years; the population was assumed to havemainly mild-to-moderate psychogenic ED. On the other hand,

Depression was found in both groups. The results of our study
were consistent with a previous study [15], which found thatyounger men had comparatively greater depressive symptoms.
In contrast, the prevalence of anxiety was not different between
the two age groups. One possible reason is that the anxiety inmen with ED is not general anxiety but specific anxiety about
sexual situations. Masters and Johnson [24] highlighted the

Discussion

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central role of sexual performance anxiety in couples presenting
with sexual dysfunction [24]. In treating sexual dysfunctions,Kaplan [25] emphasizes the importance of addressing specificsources of sexual anxiety, such as fear of failure and not pleasing
one’s partner [25]. Although a Japanese version does not exist
now, it may be necessary to use a questionnaire like the Erectile
Performance Anxiety Index [26].
Men with ED younger than 40 years had significantly higher
CFQ and VQ-OB scores than those older than 40 years in casesof moderate and severe ED. Furthermore, men withmoderate-to-severe ED younger than 40 years had significantly
higher CFQ and VQ-OB scores compared to men without ED.
These results partly support our hypothesis that men younger
than 40 years are more psychologically inflexible than thoseolder than 40 years. Cognitive fusion might be the criticalcomponent of ACT for ED. For example, the fusion with sexual
performance anxiety, such as “I might fail again,” makes it
impossible to pay attention to the sexual partner, which resultsin erectile failure. It is also consistent with Barlow’s theory[27]. Barlow [27] proposed a model for the interaction of anxiety
and cognitive interference. This model examines how anxiety
and cognitive interference interact, particularly in a sexual
context, where a lack of control over one’s arousal diverts
attention from erotic arousal to physical arousal and the negative
consequences associated with failure to attain an erection.
On the other hand, there were no significant differences in thescores of the AAQ-II, which might be related to psychometricissues with AAQ-II. To date, the most used self-report measureof psychological inflexibility, especially experience avoidance,
has been the AAQ-II. There was no significant difference in
ED severity and psychological inflexibility depending on the
duration of the marriage. However, various issues regarding the
AAQ-II have emerged from the existing literature [28]. The
authors found that the AAQ-II faced challenges in distinguishing

Saito et al
distress (like negative affect and neuroticism) from experiential
avoidance. For clinical application, researchers have expanded
the range of measures for psychological inflexibility. They havedeveloped specific versions of the AAQ-II tailored to different
populations or disorders, with currently over 20 available
versions (examples include those for the workplace, tinnitus,
irritable bowel syndrome, exercise, and epilepsy). The
disorder-specific AAQ-II variants indicate greater incremental
validity in their targeted areas than the general AAQ-II [29].
Thus, developing a questionnaire on ED-related psychologicalinflexibility might be necessary.
There are some limitations to this study. First, this study useda cross-sectional approach, indicating merely “associations”
rather than “causality” between psychological inflexibility and
ED. Further controlled experimental and longitudinal studies
are essential to delve deeper into the impact of psychologicalinflexibility on ED. Second, in this study, no responses wereobtained from the partners of men with ED. Including thepartners in the assessment and treatment of ED is recommended.
It is desirable to obtain responses from partners in future studies.
Finally, the specific racial or ethnic and socioeconomic profilesof the participants may restrict the broader applicability of thefindings. The study was also conducted during the COVID-19
epidemic, which may have influenced the results.

Conclusions
To the best of our knowledge, this web-based cross-sectional
study was the first to examine the relationship between
psychological inflexibility and ED. We conclude that men withmoderate and severe ED younger than 40 years have higher
psychological inflexibility and might be eligible for the ACT.
In addition, developing a Japanese version of the questionnaire
is necessary to measure ED-related anxiety and psychologicalinflexibility.

Data Availability
The data sets generated and analyzed during this study are not publicly available due to the Waseda University Academic Research
Ethical Review Committee’s data-sharing policy but are available from the corresponding author upon reasonable request.

Conflicts of Interest
This research was funded by Logos Science Corp, Ltd, Tokyo, Japan. MG, CS, and HT are members of the Logos Science Corp,
Ltd.

References
1.
2.
3.

4.

5.

Gloster AT, Walder N, Levin ME, Twohig MP, Karekla M. The empirical status of acceptance and commitment therapy:
a review of meta-analyses. J Contextual Behav Sci. 2020;18:181-192 [doi: 10.1016/j.jcbs.2020.09.009]
Vowles KE, McCracken LM. Acceptance and values-based action in chronic pain: a study of treatment effectiveness andprocess. J Consult Clin Psychol. 2008;76(3):397-407 [doi: 10.1037/0022-006x.76.3.397]
Gregg JA, Callaghan GM, Hayes SC, Glenn-Lawson JL. Improving diabetes self-management through acceptance,
mindfulness, and values: a randomized controlled trial. J Consult Clin Psychol. 2007;75(2):336-343 [doi:10.1037/0022-006x.75.2.336]
Lundgren T, Dahl J, Melin L, Kies B. Evaluation of acceptance and commitment therapy for drug refractory epilepsy: arandomized controlled trial in South Africa--a pilot study. Epilepsia. 2006;47(12):2173-2179 [FREE Full text] [doi:10.1111/j.1528-1167.2006.00892.x] [Medline: 17201719]
Rost AD, Wilson K, Buchanan E, Hildebrandt MJ, Mutch D. Improving psychological adjustment among late-stage ovariancancer patients: examining the role of avoidance in treatment. Cogn Behav Pract. 2012 Nov;19(4):508-517 [doi:10.1016/j.cbpra.2012.01.003]

https://formative.jmir.org/2024/1/e45998

XSL• FO
RenderX

JMIR Form Res 2024 | vol. 8 | e45998 | p. 6
(page number not for citation purposes)

JMIR FORMATIVE RESEARCH
6.
7.

8.
9.
10.

11.
12.

13.

14.

15.

16.

17.

18.
19.

20.
21.
22.
23.
24.
25.
26.
27.
28.

29.

Ferreira NM. Investigating the role of psychological flexibility and the use of an acceptance and commitment therapy based
intervention in irritable bowel syndrome. Era. 2011. URL: https://era.ed.ac.uk/handle/1842/6312 [accessed 2023-12-08]
Levin ME, MacLane C, Daflos S, Seeley JR, Hayes SC, Biglan A, et al. Examining psychological inflexibility as atransdiagnostic process across psychological disorders. J Contextual Behav Sci. 2014;3(3):155-163 [FREE Full text] [doi:10.1016/j.jcbs.2014.06.003] [Medline: 29057212]
Hayes SC, Luoma JB, Bond FW, Masuda A, Lillis J. Acceptance and commitment therapy: model, processes and outcomes.
Behav Res Ther. 2006;44(1):1-25 [doi: 10.1016/j.brat.2005.06.006] [Medline: 16300724]
Hayes SC, Strosahl K, Wilson KG, Bissett RT, Pistorello J, Toarmino D, et al. Measuring experiential avoidance: apreliminary test of a working model. Psychol Rec. 2017;54(4):553-578 [doi: 10.1007/bf03395492]
Fergus TA, Valentiner DP, Gillen MJ, Hiraoka R, Twohig MP, Abramowitz JS, et al. Assessing psychological inflexibility:
the psychometric properties of the Avoidance and Fusion Questionnaire for Youth in two adult samples. Psychol Assess.
2012;24(2):402-408 [doi: 10.1037/a0025776] [Medline: 21988185]
NIH Consensus Conference. Impotence: NIH consensus development panel on impotence. JAMA. 1993;270:83-90 [doi:10.1001/jama.270.1.83]
Dewitte M, Bettocchi C, Carvalho J, Corona G, Flink I, Limoncin E, et al. A psychosocial approach to erectile dysfunction:
position statements from the European Society of Sexual Medicine (ESSM). Sex Med. 2021 Dec;9(6):100434 [FREE Fulltext] [doi: 10.1016/j.esxm.2021.100434] [Medline: 34626919]
Boddi V, Castellini G, Casale H, Rastrelli G, Boni L, Corona G, et al. An integrated approach with vardenafil orodispersible
tablet and cognitive behavioral sex therapy for treatment of erectile dysfunction: a randomized controlled pilot study.
Andrology. 2015;3(5):909-918 [FREE Full text] [doi: 10.1111/andr.12079] [Medline: 26311340]
Atallah S, Haydar A, Jabbour T, Kfoury P, Sader G. The effectiveness of psychological interventions alone, or in combination
with phosphodiesterase-5 inhibitors, for the treatment of erectile dysfunction: a systematic review. Arab J Urol.
2021;19(3):310-322 [doi: 10.1080/2090598x.2021.1926763]
Moore TM, Strauss JL, Herman S, Donatucci CF. Erectile dysfunction in early, middle, and late adulthood: symptom
patterns and psychosocial correlates. J Sex Marital Ther. 2003;29(5):381-399 [doi: 10.1080/00926230390224756] [Medline:
14504009]
Shaeer KZM, Osegbe DN, Siddiqui SH, Razzaque A, Glasser DB, Jaguste V. Prevalence of erectile dysfunction and its
correlates among men attending primary care clinics in three countries: Pakistan, Egypt, and Nigeria. Int J Impot Res.
2003;15:8-14 [doi: 10.1038/sj.ijir.3900971] [Medline: 12825103]
Araujo AB, Durante R, Feldman HA, Goldstein I, McKinlay JB. The relationship between depressive symptoms and maleerectile dysfunction: cross-sectional results from the Massachusetts Male Aging Study. Psychosom Med. 1998;60(4):458-465[doi: 10.1097/00006842-199807000-00011] [Medline: 9710291]
Kimoto Y, Ikeda S, Nagao K, Marumo K, Tsujimura A, Kondo N, et al. The New Japanese versions of International Index
of Erectile Function (IIEF) and IIEF5. Jpn J Impot Res. 2009;24:295-308
Muramatsu K, Miyaoka H, Kamijima K, Muramatsu Y, Yoshida M, Otsubo T, et al. The patient health questionnaire,
Japanese version: validity according to the mini-international neuropsychiatric interview-plus. Psychol Rep. 2007;101(3Pt 1):952-960 [doi: 10.2466/pr0.101.3.952-960] [Medline: 18232454]
Muramatsu Y. Validation and utility of a Japanese version of the GAD-7. 2009 Presented at: Panminerva Medica 20thWorld Congress on Psychosomatic Medicine; September 23-26; Turin, Italy
Shima T, Yanagihara M, Kawai T, Kumano H. Validation of the Japanese version of the Acceptance and Action
Questionnaire-II. Proceedings of the Annual Convention of the JPA. 2013;77:1AM-042 [doi: 10.4992/pacjpa.77.0_1am-042]
Shima T, Kawai H, Yanagihara M, Kumano H. Validation of the Japanese version of the Cognitive Fusion Questionnaire:
The 13-item content revised version and the 7-Item version. Japanese J Behav Ther. 2016;42(1):73-83
Doi S, Sakano A, Muto T, Sakano Y. Reliability and validity of a Japanese version of the Valuing Questionnaire (VQ).
Japanese J Behav Ther. 2017;43(1):83-94
Masters WH, Johnson VE. Human sexual inadequacy. Brown. Little, Brown; 1970:393-450
Kaplan HS. New sex therapy: active treatment of sexual dysfunctions. London. Routledge; 2013.
Telch MJ, Pujols Y. The Erectile Performance Anxiety Index: scale development and psychometric properties. J Sex Med.
2013;10(12):3019-3028 [doi: 10.1111/jsm.12305] [Medline: 23981236]
Barlow DH. Causes of sexual dysfunction: The role of anxiety and cognitive interference. J Consult Clin Psychol.
1986;54(2):140-148 [doi: 10.1037/0022-006x.54.2.140]
Tyndall I, Waldeck D, Pancani L, Whelan R, Roche B, Dawson DL. The Acceptance and Action Questionnaire-II (AAQ-II)
as a measure of experiential avoidance: concerns over discriminant validity. J Contextual Behav Sci. 2019;12:278-284 [doi:10.1016/j.jcbs.2018.09.005]
Ong CW, Lee EB, Levin ME, Twohig MP. A review of AAQ variants and other context-specific measures of psychologicalflexibility. J Contextual Behav Sci. 2019;12:329-346 [doi: 10.1016/j.jcbs.2019.02.007]

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Abbreviations
AAQ-II: Acceptance and Action Questionnaire‐II
ACT: Acceptance and Commitment Therapy
CFQ: Cognitive Fusion Questionnaire
ED: Erectile Dysfunction
GAD-7: Generalized Anxiety Disorder‐7
IIEF-5: International Index of Erectile Function‐5
PHQ-9: Patient Health Questionnaire‐9
VQ-OB: Valuing Questionnaire–Obstacle Subscale

Edited by A Mavragani; submitted 25.01.23; peer-reviewed by M Pritchard; comments to author 03.10.23; revised version received
21.10.23; accepted 23.10.23; published 03.01.24
Please cite as:
Saito J, Kumano H, Ghazizadeh M, Shimokawa C, Tanemura H
Differences in Psychological Inflexibility Among Men With Erectile Dysfunction Younger and Older Than 40 Years: Web-Based
Cross-Sectional StudyJMIR Form Res 2024;8:e45998
URL: https://formative.jmir.org/2024/1/e45998
doi: 10.2196/45998
PMID:©Junichi Saito, Hiroaki Kumano, Mohammad Ghazizadeh, Chigusa Shimokawa, Hideki Tanemura. Originally published in JMIR
Formative Research (https://formative.jmir.org), 03.01.2024. This is an open-access article distributed under the terms of theCreative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution,and reproduction in any medium, provided the original work, first published in JMIR Formative Research, is properly cited. The
complete bibliographic information, a link to the original publication on https://formative.jmir.org, as well as this copyright andlicense information must be included.

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