Table 2.

Treatment studies for naltrexone.

Reference Type of study	Patient characteristics	Previous or concurrent treatments for CSBD	Treatment conditions (dose and duration)	Outcome measures	Efficacy
Double-blind studies
Lew-Starowicz et al. (2022) Poland	N = 73 heterosexual men (mean age 35.74 years; SD 8.09 years) with CSBD according to ICD-11; 87.7% with problematic pornography use and 100% with compulsive masturbation. No significant differences with respect to CSBD symptoms or demographic characteristics. 15 patients were suffering from sexual dysfunctions, mostly erectile dysfunction.	No previous psychiatric treatment	Group A: Paroxetine 20 mg/d Group B: Naltrexone 50 mg/d Group C: Placebo	Primary outcome: Changes in the severity of CSBD symptoms measured with SAST-R, BPS, and HBI. Additionally, craving for sexual activity and pornography vieweing were assessed via smartphone-based Ecological Momentary Assessments.	Significant decrease of self-assessed CSBD symptom severity after 8 and 20 weeks across all three groups, however, no differences between paroxetine, naltrexone and placebo. In clinical interviews paroxetine and naltrexone were found to be more effective than placebo in reducing CSBD symptoms after 8 as well as after 20 weeks. Craving for both sexual encounters and pornography viewing was reduced in the paroxetine condition but not in the other two conditions.
Open studies
Ryback (2004)	N = 21 juvenile, legally-adjudicated sexually-offending patients (in-patients) who met any of the self-reported following criteria: (1) excessive masturbation (>3 times per day); (2) feeling unable to control arousal; (3) spending more than 30% of awake time in sexual fantasies; or (4) having sexual fantasies or behaviour that regularly intruded into and interfered with their functioning in the treatment program (13–17 years of age), high rates of co-occurring ADHD (52%), depressive disorders (24%), and substance use disorders (24%)	Almost all patients were additionally treated with other medication: 52% stimulants, 38% antidepressants, 24% risperidone	Naltrexone was started at 50 mg/d in every patient, with average dose achieved being 170 mg/day (range: 100–200 mg/day)	Outcome measures were self-reported daily sexual fantasies and frequency of masturbation. A positive result was recorded if there was more than a 30% decrease in any self-reported criterion and if this benefit lasted, at least, 4 months.	No clear benefits at doses less than 100 mg/day. At 150–200 mg/day, 15 patients (71.4%) reported benefit. Masturbation frequency decreased from two times a day to two times a week. Also decreases in durations of time fantasising about sex were noted. Those six patients who did not respond to naltrexone were changed to leuprolide (3.5 mg or 7.5 mg/month). In 5 patients, stable benefit was observed at 7.5 mg IM monthly. 13 patients had naltrexone stopped after 2 months, which resulted in reoccurrence of symptoms that began when the tapered dose reached 50 mg per day.
Raymond et al. (2010) USA	N = 19 patients with paraphilic and non-paraphilic CSB Mean age 44.1 years (SD = 9.4 years, range 28–62 years). Co-occurring disorders (n): Major depression (13), dysthymia (1), depression not otherwise specified (1), Bipolar II disorder (2), cyclothymic disorder (1), generalised anxiety disorder (5), alcohol abuse (2), cannabis abuse (1), adjustment disorder (1).	Concomitant CBT in all patients; 17 patients with concomitant antidepressant treatment	Naltrexone, dosage range 50–200 mg/d. 15 Patients concurrent use of SSRI or SNRI, two patients additionally bupropion, three patients additionally bupropion and SSRI. 15 Patients were on the same medication regime for at least 6 months at the time naltrexone was initiated. 1 patient started sertraline 1 month before naltrexone. 3 patients had stopped taking dextroamphetamine, lamotrigine, and nefazodone the day naltrexone was started.	CSB rated based on the Clinical Global Impression (CGI) score	17 patients reported that CSB symptoms improved either very much or much after naltrexone treatment was started. Mean effective dose was 104 mg/d (SD = 41 mg/d). Mean treatment duration in participants who responded to treatment was 1 year (SD = 1.0 year).
Savard et al. (2020) Sweden	N = 20 men (mean age 38.8; SD = 10.3) with CSBD according to ICD-11; 95% with excessive masturbation. Exclusion criteria: 1.) alcohol dependence, use of illicit drugs in the past month, ongoing opioid or benzodiazepine medication, 2.) Severe psychiatric disorder, 3.) Change of concurrent medication or dosage in the last 3 months, 4.) Sexual behaviours with high risk to offend, 5.) Ongoing psychotherapeutic treatment. Co-occurring psychiatric disorders (n): Anxiety disorder (5), ADHD (5),	Antidepressants (2 patients) Stimulants (1 patient)	Starting dose 25 mg for 3–5 days, then increase to 50 mg/d Naltrexone 50 mg/day for 4 weeks (25 mg/day in 1 case due to fatigue)	Hypersexual disorder: Current assessment scale (HD:CAS) Hypersexual Behaviour Inventory (HBI) Sexual compulsivity scale	Significant reduction in HD:CAS scores after 2 and 4 weeks and HBI scores after 2 weeks and after 4 weeks. Increase of scores after 4 weeks without naltrexone; however, scores were below baseline scores.
Case studies
Grant and Kim (2002) USA	N = 1 man (58 years) Insatiable demand for multiple sexual partners and co-occurring kleptomania	Cognitive-behavioural therapy for 10 years Fluoxetine 80 mg/day for 16 weeks, both without change	Naltrexone 150 mg/day	Self-report	After 2 weeks with naltrexone at 150 mg/day, cessation of compulsive sexual behaviour reported. 3 days after treatment discontinuation, return of sexual urges reported. 4 days after restarting medication, remission of symptoms reported.
Raymond et al. (2002) USA	a.) N = 1 woman (42-years) frequent sexual activity with multiple partners outside her marriage; co-occurring depression b.) N = 1 man (62 years) extramarital affairs with work associates and prostitutes, preoccupation with masochistic fantasies	a.) 20–60 mg fluoxetine with lowering depressive symptoms b.) 40 mg/day fluoxetine	a.) Additionally 50–150 mg naltrexone/day b.) Additionally 50–100 mg naltrexone/day	Self-report	a.) With 100 mg /day naltrexone, almost complete remission of sexual urges; after 8 months, change from fluoxetine to citalopram at 60 mg/day; with increases in sexual urges, increased to 150 mg naltrexone, with subsequent decrease in sexual urges b.) With 40 mg/day fluoxetine, improvement in CSB, depressive symptoms and sexual preoccupation; due to difficulties in sexual functioning, fluoxetine switch to nefazodone. After stopping all medications, sexual preoccupation reoccurred; trials with fluoxetine, buproprion, citalopram and buspirone were ineffective. With 50 mg naltrexone, improvement in all symptoms; after 2 months, loss of efficacy; with naltrexone increase to 100 mg/day, improvement of symptoms for the next 8 months reported.
Bostwick and Bucci (2008) USA	N = 1 man (24 years) Preoccupation with internet pornography, multiple hours each day with sexual chats, consumption of pornography and meeting cyber-contacts for spontaneous sex.	Sertraline 100 mg/day for 1 year, group and individual psychotherapy, Sexual Addicts Anonymous, pastoral counselling	100 mg/day Sertraline + 150 mg/day naltrexone for 3 years	Self-report	After adding naltrexone, complete control over sexual impulses reported. Later, 50 mg/day achieved similar positive results.
Kraus et al. (2015) USA	N = 1 man (in his 30s) with problematic internet pornography viewing	Cognitive-behavioural therapy (CBT)	After 10 weeks of CBT, 50 mg/day naltrexone added given persistent/increased urges for viewing pornography	Self-report	After 2 weeks of naltrexone treatment, decreases in urges to masturbate to pornography reported.
Camacho et al. (2018) Portugal	N = 1 (27 years) with distressing sexual urge to have sex with transvestite men and excessive viewing of pornography (3–10 h/d)	Psychotherapy fluoxetine 20–40 mg/d, aripiprazole 10 mg/d, other antidepressants, mood stabilisers, and antipsychotics	Naltrexone 50 mg/d was added to fluoxetine 40 mg/d and aripiprazole 10 mg/d. Naltrexone was increased after several weeks to 100 mg/d.	Self-report Y-BOCS-II compulsions score	After 2 months of naltrexone treatment, significant improvement in the reduction of sexual fantasies and control of sexual impulses. No more visits of prostitutes reported. Y-BOCS-II score decreased from 14 to 0 after 2 months. After about 10 months, spontaneous stopping of naltrexone treatment and sexual compulsions returned within 2 days.