The following dialogue is one I overheard my residents and medical students having earlier this year when attempting to apply the DSM-IV criteria of “abuse” versus “dependence” to an in-patient with addiction on our service.
“Isn’t ‘abuse’ like when you get a DUI?” said the medical student.
“Yeah,” said the psychiatry resident, “and ‘dependence’ is when you get withdrawal, right?”
“I think ‘abuse’ leads to ‘dependence,’” said the neurology resident.
“Or maybe ‘abuse’ is not as bad as ‘dependence’?”
“So what about our patient? He’s pretty hard-core.”
“I see him all the time in the emergency room. Totally intoxicated.”
“I’ve seen him drunk on the train.”
That sealed the deal.
“Dependence it is!” they all agreed.
The process by which my students arrived at this diagnosis was, needless to say, less than scientific, and included scant reference to the major anchor points in the DSM-IV. Yet in my experience, the notion of severity is probably the most common anchor point clinicians use in deciding between abuse and dependence, with abuse generally accepted as a less severe form of addiction than dependence. The DSM-IV itself makes little or no concession to severity or disease progression, and no scientific studies support abuse as a precursor to dependence.
The truth is, the DSM-IV distinction between abuse and dependence has never made much clinical sense, does little to enhance understanding or guide treatment, and as practically applied can be as arbitrary as “drunk on the train.”
This is why I welcome the DSM-5, despite the unprecedented vociferous criticism voiced by many professionals. In the new version, due out later this month, the categories of abuse and dependence are done away with, leaving in their place the single category of “substance use disorder.” The first gain: only one list of wordy criteria to memorize. Second gain: eliminating the confusing and invalid dichotomy between abuse and dependence.
The new DSM-5 embraces addiction as a spectrum disorder with the qualifiers of “mild,” “moderate,” and “severe.” A scaled approach to addiction is clinically apt: We’ve all treated patients with varying levels of severity. A spectrum not only enables health care providers to capture this variance but also provides specific guidelines on how to rate degrees. If the patient endorses two or three items on the list, then she has a “mild substance use disorder,” if four or five items, “moderate,” and if six or more items, “severe.” For example, the patient who describes “a persistent desire ... to control substance use,” “important ... activities given up because of substance use,” “the substance taken in larger amounts than was intended” and “tolerance”—four items—has a “moderate substance use disorder.”
Why sacrifice the available evidence-based quantitative guidelines for uniformity based on qualitative-only guidelines?
Even AA, the mother ship of categorical definitions of addiction, acknowledges the difference between “low-bottom” and “high-bottom” drunks. Other disorders in the DSM, such as depression, have long included the qualifiers “mild,” “moderate,” and “severe.” It is high time that the DSM incorporated the idea of a spectrum in its phenomenology of all addictive disorders.
Despite my approval of this revision, I am disappointed that the new spectrum approach continues to be based solely upon qualitative and subjective criteria while ignoring the abundance of quantitative data. As scientifically defined, spectrum captures qualitative differences arising from a quantitative continuum, like the physical wavelengths of light that yield discrete colors. The new DSM, wherever possible, should base its qualitative categories on a quantitative continuum as well. As it happens, such a quantitative continuum exists. There is an ever-growing body of evidence demonstrating that quantity and frequency of substance use, particularly alcohol, are tied to risk of disease and death.
To take only one of many examples, a study I did with colleagues, published in the Journal of General Internal Medicine in 2011, followed 215,924 men and 9,168 women for two years to evaluate how quantity and frequency of alcohol use affected rates of gastrointestinal-related illness. Not surprisingly, we found that excessive alcohol use is associated with increased risk of GI-related hospitalization, new-onset liver disease, upper Gl bleeding, and pancreatitis.
A growing medical consensus defines “risky drinking” as, for men, more than 14 standard drinks per week, or more than four per occasion; and for women, more than seven standard drinks per week, or more than three per occasion (one standard drink equals 12 ounces of beer, five ounces of wine, or one and a half ounces of hard liquor). Risky drinking is associated with increased morbidity and mortality, and correlates with DSM-IV criteria for a substance use disorder.
In spite of these compelling data, nowhere in the DSM is quantity or frequency of consumption addressed.
Why is it essential to incorporate quantitative data similar to those for "risky drinking" into the DSM? Because of a problem drinker’s psychological denial. A patient who drinks three pints of vodka every night but denies all of the DSM criteria for a substance use disorder is most likely an alcoholic. A quantitative reference point would allow clinicians to make the appropriate diagnosis, even in the absence of subjective acknowledgement of addiction, which we all recognize as part of the disease itself.
I asked a colleague of mine who was involved in the DSM-5 revision of substance use disorders why quantity and frequency were not included in the criteria. He said that it was too difficult to come up with a uniform diagnosis for all types of substance use disorders (alcohol, marijuana, cocaine, heroin, etc.) while also including quantity and frequency. I see his point. Standard drinks cannot be easily translated into hits of marijuana.
But why sacrifice the available evidence-based quantitative guidelines for uniformity based on qualitative-only guidelines? Conferring greater precision on alcohol use disorders might spur researchers to further explore quantity and frequency for the other substances. Even lacking data for marijuana, cocaine, and the rest, the DSM-5 might have mirrored its criteria for bulimia nervosa: “eating, in a discrete period of time, an amount of food that is definitely larger than most people would eat during a similar period of time and under similar circumstances.”
There are obvious imperfections to this strategy, especially an addict’s tendency to normalize his use and affiliate with others who consume excessively. Still, I think that any attempt to quantify is a big step in the right direction.
Bottom line: The DSM-5’s spectrum approach to diagnosing substance use disorder is an improvement. But the revision could have been bolder in defining the spectrum by mining the wealth of data on the link of quantity and frequency of alcohol consumption to health outcomes.
I encourage health care professionals, when screening for substance use disorders, to assess quantity and frequency of consumption in addition to DSM criteria, and incorporate these data when making a diagnosis and treatment plan.