Background     A very commonly requested educational pain topic by clinicians, surrounds differentiating the patient in pain from the patient with a substance abuse disorder.  The key to proper assessment lies in understanding 1) the definitions of tolerance, physical and psychological dependence, 2) the components of an addiction assessment, and 3) the differential diagnosis of the symptom of “pain.”    

Definitions

• Tolerance: the need to increase a drug to achieve the same effect. In clinical practice, significant opioid tolerance is uncommon.  Tolerance may be present in the pain patient or the addict; by itself it is not diagnostic of addiction.
• Physical Dependence: development of a withdrawal syndrome when a drug is suddenly discontinued or an antagonist is administered.  Most patients on chronic opioids will develop physical dependence; its presence cannot be used to differentiate the pain patient from the addict.
• Psychological Dependence (Addiction): overwhelming involvement with the acquisition and use of a drug, characterized by: loss of control, compulsive drug use, and use despite harm.   Research suggests that opioids used to treat pain rarely leads to psychological dependence.

Addiction (Substance Abuse) Assessment      Assess for addiction in the domains presented in the list below (see Reference 1).  Note: one positive item from the list does not establish a substance abuse disorder.  Rather, the diagnosis rests on a pattern of behavior that includes several positive findings (see Reference 4).

• Loss of control of drug use (has no partially filled med bottles; will not bring in bottles for verification).
• Adverse life consequences – use despite harm (legal, work, social, family).
• Indications of drug seeking behavior (reports lost/stolen meds, requests for high-street value meds).
• Drug taking reliability (frequently takes extra doses, does not use meds as prescribed).
• Abuse of other drugs (current/past abuse of prescription or street drugs).
• Contact with drug culture (family or friends with substance abuse disorders).
• Cooperation with treatment plan (does not follow-up with referrals or use of non-drug treatments).

Differential Diagnosis       The differential diagnosis for a patient reporting “pain” includes physical causes (broken leg, sciatica, pseudoaddiction – see Fast Fact #69); psychological causes (depression, anxiety, hypochondriasis, somatization disorder, etc.); spiritual causes (impending death, grief); substance abuse; and secondary gain/malingering/criminal intent (desire for attention, disability benefit, or financial gain from pain medications). 

References

1. Sees KL, Clark HW.  Opioid use in the treatment of chronic pain: assessment of addiction. J Pain Symptom Manage. 1993; 8:257-264.
2. Savage SR. Addication in the treatment of pain: significance, recognition and management. J Pain Symptom Manage. 1993; 8:265-278.
3. Eisendrath SJ. Psychiatric aspects of chronic pain. Neurology. 1995; 45:S26-S34.
4. Passik SD, Kirsh KL, Portenoy RK.  Understanding aberrant drug-taking behavior: addiction redefined for palliative care and pain management settings.  Principles and Practice of Supportive Oncology Updates. 1999; 2:1-12.

Version History:  This Fast Fact was originally edited by David E Weissman MD. 2nd Edition published July 2006; 3rd Edition May 2015. Current version re-copy-edited April 2009; then again May 2015.