The following is taken from a paper on limerence by Albert Wakin & Duyen B. Vo. This is one of the best recent papers on this condition.
The Diagnostic and Statistical Manual (DSM) defines substance dependence (i.e., addiction) as a pattern of substance use that causes clinically significant impairment or distress at any time within a 12-month period. Substance dependence is marked by a need for increased amounts of the substance to achieve a desired effect (i.e., tolerance), and unpleasant physiological and cognitive effects that result from reduced blood or tissue concentrations of the substance (i.e., withdrawal).
It is also marked by a pattern of compulsive substance use wherein there are: persistent increase of time in obtaining and in recovering from the substance, unsuccessful efforts to control substance use, impaired functioning related to substance use, and continued substance use despite negative physical or psychological effects. For the sake of comparison, the object of substance dependence is the substance, while the object of limerence is another person.
In limerence, LE ultimately experiences impairment and distress. Like in substance dependence, LE experiences tolerance, in that he/she displays a markedly greater and greater need for emotional reciprocation from the person/substance in order to maintain the desired level of happiness. Actual or potential absence of the person/substance results in withdrawal symptoms such as physical pain in the chest and abdominal regions, sleep disturbance, irritability, and depression.
Further, similar to substance dependence, limerence can also be marked by a pattern of compulsive behavior, where LE devotes more and more time to planning for and gaining access to the person/substance. LE is unable to control and reduce the need for the person/substance despite being cognizant of the excessive and negative effects on his/her ability to function.
In terms of obsessive compulsive disorder (OCD), it is defined by persistent obsessions and compulsions that are time-consuming and interfere with daily activities, causing clinically significant impairment or distress. Obsessions are persistent, intrusive, and inappropriate ideas, thoughts, impulses or images that cause anxiety or distress.
Compulsions are repetitive behaviours or mental acts that reduce obsession-related anxiety. In OCD, the obsessions and compulsions cannot be controlled and are continued despite perceived excessiveness and unreasonableness.
Limerence also exhibits obsessive and compulsive features that highly resemble OCD. Like OCD, there is an undercurrent of anxiety, but in limerence the anxiety centers on emotional rejection by the LO. L is likely to engage in repetitive behaviours and/or mental acts in order to reduce and neutralise this underlying anxiety, such that these obsessions and compulsions become highly time-consuming to the point of interfering with and impairing L’s functioning.
Although [substance] dependence/addiction and obsession-compulsion are integral, each alone is insufficient for the determination of limerence and both in combination would be a simplification of limerence. In other words, limerence is not simply an addiction to another person with obsessive-compulsive features, nor is it an OCD with addictive characteristics.
When reduced to their basic elements, the goal of substance dependence is to achieve an altered state often as a method of coping, while the means is the substance itself. As OCD is an anxiety disorder, its inherent goal is to neutralise the underlying anxiety through repetitive behaviours and/or mental acts.
The goal of limerence on the other hand is to attain emotional reciprocation, but the means are elusive and indeterminate as they are contingent on perceived behavioural feedback from another person. Since the feedback constantly changes as the behaviour of the LO changes both naturally and in response to LE’s own behaviour, LE becomes hypersensitive to LO’s behavioural cues which act as a gauge for his/her success and as a guide for his/her own behaviour.
Therefore LE’s means are constantly being calibrated and re- calibrated to optimise the likelihood of successfully attaining emotional reciprocation. Merely defining limerence as an obsessive-compulsive addiction or an addictive OCD would be a failure to consider the nature of the interpersonal nuances between LE and LO and how they compound to complicate the overall process of limerence.