Aims: Inquiry regarding the relationship between passionate love and addiction has long been a topic of intense debate. Recent advances in neurobiology now allow for an examination between these two states. Methods: After describing the clinical distinctions between “love passion,” “love addiction,” and “sex addiction,” we compare clinical, neuropsychological, neurobiological, and neuroimaging data on love, passion, pathological gambling (PG) and substance dependence. Results: There are no recognized definitions or diagnostic criteria for “love addiction,” but its phenomenology has some similarities to substance dependence: euphoria and unrestrained desire in the presence of the love object or associated stimuli (drug intoxication); negative mood, anhedonia, and sleep disturbance when separated from the love object (drug withdrawal); focussed attention on and intrusive thoughts about the love object; and maladaptive or problematic patterns of behavior (love relation) leading to clinically significant impairment or distress, with pursuit despite knowledge of adverse consequences. Limited animal and human studies suggest that brain regions (e.g., insula, anterior cingulated [ACC], orbitofrontal [OFC]) and neurotransmitters (dopamine) that mediate substance dependence may also be involved with love addiction (as for PG). Ocytocin (OT), which is implicated in social attachment and mating behavior, may also be involved in substance dependence. There are no data on the epidemiology, genetics, co-morbidity, or treatment of love addiction. Conclusion: There are currently insufficient data to place some cases of “love passion” within a clinical disorder, such as “love addiction,” in an official diagnostic nomenclature or to firmly classify it as a behavioral addiction or disorder of impulse control. Further clinical and scientific studies are needed to improve our understanding and treatment of this condition. For these studies, we propose new criteria for evaluating addiction to love.