In his book Sexual Addiction, Dr. Aviel Goodman proposed that all addictions "share an underlying psychobiological process," which he called the addictive process. According to Goodman,
the addictive process originates in an impairment of the self-regulation system, the internal psychobiological system that regulates one's subjective (sensory, emotional, and cognitive) states and one's behavioral states. Impaired internal regulation of their subjective states leads individuals to depend on external actions to regulate their subjective states and to cope with the subjective consequences of internal dysregulation. Impaired internal regulation of their behavioral states limits individuals' capacity to modulate or to inhibit urges to engage in such compensatory actions. Addictive behavior thus represents both an attempt to cope with the subjective consequences of impaired self-regulatory functioning, and an overt manifestation of impaired self-regulatory functioning.
In the case of sexual addiction, Goodman suggested that either the addict had been sexually stimulated by a parent while growing up or the addict had identified with a sexualizing parent. What's more, the addict had learned to expect sexual behaviors to not only provide pleasure but also to relieve painful or dangerous affects. As researchers have noted, sexual addiction is more often than not a result of overt or covert incest.