This chapter is directly related to Section D(ii) from the 2017 CICM Primary Syllabus, which expects the exam candidate to "define... addiction, dependence..." along with several other related terms.  Though this appears in the college syllabus, and is therefore potentially examinable, it has never appeared in the exams, and can therefore be ignored during the end stages of pre-test revision.

The official recommended text (Katzung, 14th ed) does not have much to say on this topic, and so the next best resource is probably Goodman & Gilman's Chapter 24 by Charles O'Brien (p. 649 of the 12th edition). This is a detailed and comprehensive review of the topic, which may be excessive for somebody who only needs a superficial level of understanding suited for an SAQ answer. And in any case, it does not help anybody "define... addiction, dependence" as it contains no definitions per se. In order to get definitions for some of these, one needs to look at obsolete copies of the APA's DSM (4th edition) and addiction medicine journals where angry academics war with each other over nomenclature.

In summary:

  • Addiction is a behavioural pattern of preoccupation with the use of a drug, associated with use-related satiation, loss of control and continued use despite evidence of harm.
    • A preoccupation with using the drug needs to be a part of it
    • Engaging in the behaviour should result in satiation
    • Loss of control (impulsiveness, compulsion) should form a part of it
    • Perseverance of the behaviour despite negative consequences also seems important
  • Dependence is a state which is behaviourally distinct from addiction, characterised by tolerance and the development of a withdrawal syndrome.
    • Dependence can occur without addiction
  • Withdrawal is the physiological syndrome which occurs when there is tolerance to a drug and it is discontinued

Definition of addiction

Addiction is one of these terms in pharmacology which has enough of a relationship with its colloquial homonym for the two to be interchangeable, and like obscenity ("I know when I see it") most people will find it difficult to generate a formal-sounding definition. In the event that CICM candidates are ever forced to come up with one at an SAQ or viva, a suitable definition can be borrowed from the authoritative-sounding American Society for Addiction Medicine, who define it as

"...a primary, chronic disease of brain reward, motivation, memory and related circuitry. Dysfunction in these circuits leads to characteristic biological, psychological, social and spiritual manifestations. This is reflected in an individual pathologically pursuing reward and/or relief by substance use and other behaviors.

Addiction is characterized by inability to consistently abstain, impairment in behavioral control, craving, diminished recognition of significant problems with one’s behaviors and interpersonal relationships, and a dysfunctional emotional response. Like other chronic diseases, addiction often involves cycles of relapse and remission."

That's their short definition of addiction. Obviously, the exam candidate would be looking for something a bit more compact and pithy.  The DSM V, probably a definitive resource for this, briefly defines addiction as:

"...a maladaptive pattern of substance use leading to clinically significant impairment or distress"

qualifying the statement with the need for at least three of a series of criteria which include tolerance and withdrawal. That short line is probably enough for CICM examiners, and it comes from a peer-reviewed resource. If one resorts to using material from the lawless wasteland of the FOAM internet, one will come across an excellent definition from the Part One authors:

"Addiction is a behavioural pattern characterised by compulsive use and fixation on acquiring and using a drug"

It's not clear where they got this from, but it certainly outdoes the other "official" definitions in terms of brevity and value. In short, whatever definition of addiction you end up using, it should probably acknowledge several defining features which seem common among authors. These were identified and discussed in a good article by Sussman & Sussman (2011). In their opinion, a good definition needs to include a number of domains:

  • It must involve a behavioural change
  • A preoccupation with using the drug needs to be a part of it
  • Engaging in the behaviour should result in satiation
  • Loss of control (impulsiveness, compulsion) should form a part of it
  • Perseverance of the behaviour despite negative consequences also seems important

Dependence

In 1964, the WHO committee recommended we substitute the word "dependence" for both "addiction" and "habituation", which had given rise to a horrific mess of nomenclature (Rinaldi et al, 1988). Fortunately, in this enlightened age, we have the APA and the Diagnostic and Statistical manual. The fourth edition covered dependence as a series of criteria, of which at least 3 must be satisfied in order to descrbe somebody as "drug-dependent": 

  • Withdrawal must be observed
  • Tolerance must be demonstrated 
  • Use of larger amounts for longer
  •  Repeated atempts to quit or control use
  • Much time spent using
  • Physical/psychological problems related to use
  • Activities given up to use

In the new (2013) DSM V, the old criteria describing "abuse" and "dependence" were grouped under the umbrella "substance abuse disorders", and the definition of dependence was lost. The best we can have these days are textbooks like Goodman & Gilman (12th ed, p.649). There, dependence is described as "progressive pharmacological adaptation to the drug" with some necessary features:

  • It is an entity distinct from addiction
  • It requires tolerance to develop
  • It results in withdrawal syndrome

Thus, dependence is a state which is behaviourally distinct from addiction, because it does not describe compulsive use. It is a purely pharmacological phenomenon, which can apply to substances which have no pleasant CNS effects, for example beta-blockers.

Withdrawal

The ICD-10 defines withdrawal as 

"A group of symptoms of variable clustering and severity occurring on absolute or relative withdrawal of a psychoactive substance after persistent use of that substance."

This is descriptive but does not specifically address what happens. Goodman & Gilman suggest it is "signs and symptoms occur when drug administration in a physically dependent person is terminated abruptly" but also fail to discuss what specific features make up withdrawal. Through examples and parables the textbook ultimately also describes these features:

  • Withdrawal is a biological/pharmacological phenomenon
  • It occurs due to the existence of a tolerance to that drug 
  • Withdrawal effects tend to be opposite to the original effects produced by the drug before tolerance developed
  • It is not necessary for the diagnosis of a substance use disorder

This draws a distinction between pharmaclogical withdrawal  "psychological withdrawal", where behavioural changes occur in response to the cessation of a drug which are unrelated to any physiological adaptve effects. 

References

Sussman, Steve, and Alan N. Sussman. "Considering the definition of addiction." (2011): 4025-4038.

Rinaldi, Robert C., et al. "Clarification and standardization of substance abuse terminology." JAMA 259.4 (1988): 555-557.