Sexual Dysfunction and Paraphilic Disorders

Sexual dysfunctions are clinically significant disturbances in the ability to respond sexually or to experience sexual pleasure, present for at least 6 months, causing distress, and not better explained by another condition, substance, or relationship difficulty. Paraphilic disorders are persistent atypical sexual interests that cause distress or impairment to the person, or harm or risk of harm to others.

Sexual dysfunctions (DSM-5 categories)

• Male: erectile disorder, delayed ejaculation, premature (early) ejaculation, male hypoactive sexual desire disorder.
• Female: female sexual interest/arousal disorder, female orgasmic disorder, genito-pelvic pain/penetration disorder (dyspareunia, vaginismus).
• Substance- or medication-induced sexual dysfunction, and other specified or unspecified dysfunction.

Prevalence:

• Male: erectile dysfunction about 20% overall and increasing with age (about 50% by 60 years), premature ejaculation 20 to 30% by self-report (3 to 5% with strict criteria), low desire 5 to 15%.
• Female: low desire or arousal difficulty about 30 to 40% (with distress about 10%), orgasmic difficulties 10 to 20%, dyspareunia 10 to 20%.

Aetiology, usually multifactorial:

• Biological: vascular disease, diabetes, neuropathy, hypogonadism, hyperprolactinaemia, thyroid disease, pelvic surgery or radiation, spinal cord injury, multiple sclerosis, chronic illness, menopause and genitourinary syndrome of menopause, chronic pain, pelvic floor dysfunction.
• Drugs: SSRIs and SNRIs (delayed orgasm in 30 to 60%, decreased libido), antipsychotics (via prolactin), antihypertensives (beta blockers, thiazides, spironolactone, clonidine), antiandrogens, opioids, hormonal contraception, 5-alpha reductase inhibitors, anticonvulsants, benzodiazepines, alcohol, nicotine, cannabis and stimulants.
• Psychological: depression, anxiety, performance anxiety, trauma including sexual abuse, body image concerns, stress, and personality factors.
• Relational and sociocultural: partner conflict, mismatched desire, poor communication, lack of sexual knowledge, religious or cultural beliefs.

Paraphilic disorders

• Paraphilias (not disorders unless they cause distress or harm): voyeuristic, exhibitionistic, frotteuristic, sexual masochism, sexual sadism, pedophilic, fetishistic and transvestic disorder.
• Prevalence is difficult to establish. Voyeuristic and exhibitionistic interests are the commonest in the community. Most offenders are men.
• Hypersexuality or compulsive sexual behaviour disorder is separately recognised (ICD-11) and is characterised by repetitive, intense sexual impulses with failed efforts to control them.
• Neurobiological factors include frontal and temporal lobe lesions, dementia, Klüver-Bucy syndrome, and drug-induced disinhibition (dopamine agonists). Psychosocial factors include childhood sexual abuse, comorbid personality disorder, substance use, and cognitive distortions.

Sexual history (non-judgemental, open questions, normalise the discussion)

• Nature of the problem (desire, arousal, orgasm, ejaculation, pain), onset (lifelong versus acquired), course (situational versus generalised), duration, severity, and associated distress.
• Presence of morning and nocturnal erections, masturbation function (differentiates psychogenic from organic erectile problems), partner factors, relationship quality, sexual orientation and gender identity.
• Medical, surgical, psychiatric, medication, substance and trauma history. Cardiovascular risk, as erectile dysfunction may precede coronary events by 2 to 5 years.
• Validated tools: International Index of Erectile Function (IIEF-5, score 21 or below indicates dysfunction), Premature Ejaculation Diagnostic Tool, Female Sexual Function Index (FSFI, total score below 26.55), Female Sexual Distress Scale.

Clinical patterns

• Premature ejaculation: ejaculation within about 1 minute of vaginal penetration (lifelong) or a clinically significant reduction to about 3 minutes (acquired), with inability to delay and distress. The intravaginal ejaculatory latency time is measured by stopwatch in research.
• Delayed ejaculation: marked delay or inability to ejaculate despite adequate stimulation, often drug-related (SSRIs), or neurological, androgen-related, or from prostate surgery.
• Female sexual interest/arousal disorder: reduced interest, fewer fantasies, lack of arousal or genital sensation.
• Genito-pelvic pain/penetration disorder: pain with penetration, fear of pain, and pelvic floor tension. Vaginismus appears with involuntary muscle spasm.
• Paraphilic disorders: history of recurrent intense fantasies, urges or behaviours over at least 6 months, with distress or involvement of non-consenting individuals. Assess risk to others, victim age, offending history and legal status, and mental state. Child sexual abuse material and offences require legal reporting duties according to jurisdiction.

Examination

• Blood pressure, BMI, waist circumference, secondary sexual characteristics, thyroid, breast (gynaecomastia), genital examination (penile plaques in Peyronie disease, phimosis, testicular size and consistency), prostate, peripheral pulses, and neurological examination including bulbocavernosus reflex and perineal sensation.
• Female: vulvar skin (lichen sclerosus, atrophy), vestibulodynia (cotton-swab test), vaginal examination for pain, prolapse and pelvic floor tone, and speculum if appropriate.

Red flags: sudden onset, trauma, neurological signs, pelvic pain, evidence of hypogonadism, cardiac symptoms on exertion, severe depression or suicidality, history of abuse, coercion, and any involvement of children.

Diagnosis is clinical and based on history. Targeted tests exclude organic causes.

Laboratory:

• Fasting glucose or HbA1c, lipid profile, and renal and liver function.
• Morning (8 to 10 am) total testosterone, repeated if low, with sex hormone binding globulin or free testosterone, LH and FSH, and prolactin for low testosterone or low libido. Total testosterone below 8 nmol/L (230 ng/dL) is consistently low, and 8 to 12 nmol/L is borderline.
• TSH, and in women, FSH, LH, oestradiol, prolactin and TSH when menstrual change or menopause is relevant. Testosterone testing in women is of limited value.
• CBC, ferritin, vitamin B12 when relevant.
• Cardiovascular risk assessment (Princeton consensus risk stratification of exertional capacity).

Specialist tests (selected):

• Penile duplex Doppler ultrasound after intracavernosal injection (peak systolic velocity below 25 cm/s indicates arterial insufficiency, end-diastolic velocity above 5 cm/s suggests venous leak), nocturnal penile tumescence, neurophysiology.
• Pelvic examination, pelvic ultrasound or MRI, and vaginal pH or smears for dyspareunia.
• Colposcopy and vestibular biopsy for chronic vulvar pain.
• Psychological assessment: depression (PHQ-9), anxiety (GAD-7), post-traumatic stress, substance use, relationship assessment.
• For paraphilic disorders: structured clinical interview, risk assessment tools (Static-99R, STABLE-2007, SVR-20) for offending risk, and forensic and psychiatric evaluation. Phallometric testing and polygraph are specialist tools. Brain imaging for new-onset paraphilia in older adults or with neurological signs.

General principles

• Treat the cause, modify medications, optimise chronic disease, and use combined biopsychosocial treatment. Involve the partner. Provide education, address misconceptions, and set realistic goals.
• Lifestyle: exercise, weight loss, smoking cessation, reduced alcohol, and sleep.

Erectile dysfunction

• PDE5 inhibitors are first line (see phosphodiesterase inhibitors): sildenafil 25 to 100 mg one hour before sex, tadalafil 10 to 20 mg on demand or 2.5 to 5 mg daily, vardenafil 10 to 20 mg, avanafil 100 to 200 mg. Contraindicated with nitrates and riociguat.
• Alternatives: vacuum erection devices, intracavernosal alprostadil 5 to 20 micrograms, intraurethral alprostadil 125 to 1000 micrograms, penile prosthesis, and testosterone therapy in proven hypogonadism.

Premature ejaculation

• Behavioural methods: stop-start and squeeze techniques, pelvic floor training, and sex therapy.
• Dapoxetine 30 mg (maximum 60 mg) 1 to 3 hours before sex (where licensed), paroxetine 10 to 40 mg daily or 20 mg 3 to 4 hours before sex, sertraline 50 to 100 mg daily, fluoxetine 20 to 40 mg daily, clomipramine 12.5 to 50 mg daily, tramadol 50 mg on demand (limited by dependence risk), topical anaesthetic (lidocaine-prilocaine cream or lidocaine spray 10% applied 10 to 20 minutes before intercourse), and condoms with benzocaine. Use PDE5 inhibitors when ED coexists.

Delayed ejaculation

• Reduce or switch implicated drugs (for example, SSRIs to bupropion), cabergoline 0.5 mg twice weekly, buspirone 10 to 20 mg twice daily (evidence is limited), testosterone for hypogonadism, and sex therapy with vibratory stimulation.

Low desire and hypogonadism

• Testosterone replacement for male hypogonadism (gels 1.62% 40.5 mg daily, injections of testosterone undecanoate 1000 mg every 10 to 14 weeks, or enanthate 200 mg every 2 weeks), with monitoring of haematocrit (stop if above 54%), PSA and lipids.
• Treat depression, hyperprolactinaemia (cabergoline 0.25 to 0.5 mg twice weekly), thyroid disease and relationship issues.

Female sexual dysfunction

• Education, cognitive behavioural therapy, mindfulness, sensate focus and couples therapy are first line for desire and arousal disorders.
• Genitourinary syndrome of menopause: lubricants, vaginal moisturisers, vaginal oestradiol 10 micrograms daily for 2 weeks then twice weekly, intravaginal DHEA (prasterone 6.5 mg nightly), or ospemifene 60 mg daily.
• Systemic transdermal testosterone (300 micrograms daily in postmenopausal women with hypoactive sexual desire disorder, available in some regions) for up to 6 months, with monitoring. Flibanserin 100 mg nightly (premenopausal, avoid alcohol, strong CYP3A4 inhibitors) and bremelanotide 1.75 mg subcutaneously before sex are FDA-approved options for premenopausal women with acquired generalised hypoactive desire.
• Replace or modify offending medications. Bupropion 150 to 300 mg daily for SSRI-related dysfunction.
• Genito-pelvic pain: pelvic floor physical therapy, graduated vaginal dilators with lidocaine 2% gel, topical lidocaine 5% before intercourse, treatment of vestibulodynia (topical amitriptyline 2% with baclofen 2%, botulinum toxin, vestibulectomy in refractory cases), and psychosexual therapy.

Paraphilic disorders

• Combined psychological and pharmacological management tailored to risk, in a forensic or specialist service.
• Psychotherapy: cognitive behavioural therapy focused on relapse prevention, empathy, cognitive distortions and self-regulation, and group therapy.
• Pharmacological treatment (graded approach, with informed consent and monitoring):
• First step for mild-moderate disorders with preserved control: SSRIs (sertraline 50 to 200 mg daily, fluoxetine 20 to 60 mg daily), reduce paraphilic urges in many.
• For moderate-severe risk, add antiandrogen therapy: cyproterone acetate 50 to 300 mg daily (liver function monitoring, hepatotoxicity, depression, bone density) or medroxyprogesterone acetate 100 to 400 mg IM weekly to monthly.
• For high-risk cases: GnRH agonists (leuprolide 7.5 mg monthly or 22.5 mg every 3 months, triptorelin 3.75 mg monthly or 11.25 mg every 3 months), with initial flare covered by cyproterone 100 mg daily for 2 to 4 weeks. Monitor testosterone, bone density (DEXA at baseline and every 1 to 2 years), vitamin D and calcium, lipid and glucose, and metabolic complications.
• Treat comorbid mental illness, substance misuse, impulsivity and mood disorders. Naltrexone 50 to 150 mg daily is used for compulsive sexual behaviour.
• Risk management: legal and safeguarding obligations, multi-agency public protection arrangements, supervision, and safety planning. Therapy aims to reduce harm, not just distress.

Follow-up

• Review within 4 to 8 weeks after starting treatment, with monitoring of efficacy, adverse effects, and relationship. Stop ineffective medications. Provide ongoing psychosexual therapy or referral to sexual medicine, gynaecology, urology, endocrinology or psychiatry as appropriate.