How do you know if a given behaviour or group of symptoms constitutes a psychiatric or psychological disorder? This is an important question, and particularly relevant right now as psychiatrists work on the fifth version of the Diagnostic and Statistical Manual of Mental Disorders (DSM), to be published in 2013.
Proposed additions to the DSM like Internet Addiction and Premenstrual Dysphoric Disorder (PMDD) are raising the ire of DSM critics who argue that the manual medicalizes and pathologizes normal behaviour. While this criticism is valid and worthy of discussion, people making this argument have the frustrating habit of selecting one symptom from the list of DSM criteria for a given disorder and using it to claim that the criteria describe normal behaviour. The most recent person to do so is Ian Brown of the Globe & Mail. In his article, Brown gives the example of one criterion for the proposed DSM-V diagnosis of compulsive hoarding: "Persistent difficult discarding or parting with possessions, regardless of the value others may attribute to those possessions."
According to Brown, this symptom describes "anyone with a basement." Such is the problem of selecting and criticizing a diagnostic criterion in isolation. Anyone wishing to make a similarly unsophisticated argument could choose "Eating, in a discrete period of time, an amount of food that is definitely larger than most people would eat in a similar period of time under similar circumstances" from the proposed criteria for binge eating disorder (BED) or "Marked affective lability (e.g., mood swings; feeling suddenly sad or tearful or increased sensitivity to rejection) prior to most menstrual cycles" from the proposed criteria for PMDD. They could argue that they often overeat at dinner parties and experience mood swings before they menstruate and that the inclusion of BED and PMDD in DSM-V would unfairly pathologize their behaviour.
This argument fails to acknowledge a) the other diagnostic criteria for the respective disorders and, importantly, b) the additional criterion of significant distress. The diagnostic criteria for most of the DSM disorders include "Symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning." This is a key criterion: If you have a basement full of junk, but it's not bothering you or anyone else (and not causing a health or safety risk), no one is going to accuse you of being a compulsive hoarder. If you overeat at dinner parties and binge on chips during the Superbowl, but it doesn't cause you lasting distress (or health problems), no one is going to label you with binge eating disorder. Writers like Brown are advised to keep the distress criterion in mind--as well as the entirety of the criteria for a given disorder--when they're fretting about the pathologizing of normal behaviour.
NB: My endorsement of the significant distress criterion is not a defense of the singular use of the DSM to decide what is and isn't a clinical problem. If your symptoms or behaviour don't cause you distress or impairment, you probably don't have a clinical problem. But: if you experience significant distress or impairment despite having only minor symptoms, it's still a problem. That is, if you binge eat only four times per year at holidays or only experience mood swings every third time you menstruate--but it causes you significant distress or impairment--ignore the doctor telling you your symptoms are subclinical according to the DSM, and seek help elsewhere. Distress is distress.