The endocannabinoids don't appear to play any part in alcohol or drugs but they certainly do in eating disorders. It’s my guess that sexual compulsivity involves both a dopamine problem and an endocannabinoid problem.
All of the brains systems are intricately related and produce a homeostatic state. Our brains stay in homeostasis, unless we're born deficient in one or more of them or unless something wears out one of those systems. With alcohol and drugs there's a dopamine deficiency or a down regulated system. It's being looked at in sexual compulsivity but it's going to be the same thing.