Behavioural addictions (BAs) \[gambling disorder (GD), food addiction (FA), sexual addiction (SA)\] may lead to disastrous consequences. They are often associated with other addictive or psychiatric disorders, and high rates of suicide attempts. Epidemiological studies report prevalence reaching 2.7% for GD, 5% for SA, and up to 7.9% for FA.
Many similarities have been highlighted between BAs, as well as with substance use disorders. One core clinical similarity between those disorders is craving (uncontrollable urge to engage in rewarding behaviours), which has been consistently associated with diminished control over the behaviour and relapse.
At present, no pharmacological treatment has been approved for BAs, but several medications have been tested. Among them, two opioid receptor antagonists - naltrexone and nalmefene - appear the most promising. By decreasing dopamine neurotransmission in the reward circuitry, they reduce both excitement for rewarding behaviours and craving.
Compared to naltrexone, nalmefene seems to have a better safety. To date, no study investigated the efficacy of nalmefene as a pan-addiction treatment for BAs. Two clinical trials have demonstrated its efficacy for the treatment of GD, but no clinical trial was conducted for FA and SA.
The investigators hypothesise that nalmefene (36 mg/d), compared to a placebo, can have a therapeutic effect as an add-on to usual treatment for decreasing craving in several BAs.