Overview
Treating a substance use disorder can be challenging. Potentially complicating the treatment of an SUD is the presence of a comorbid chronic medical condition. Not only can problematic alcohol or substance use cause the onset or acquisition of some medical conditions, active alcohol and other substance use can exacerbate medical problems, complicate the treatment of medical problems, and have adverse effects on disease course and prognosis. To illustrate these complications and how to effectively address them using cognitive-behavioral interventions, we have organized this chapter into six sections: (1) the prevalence, clinical presentations, and complications of having a comorbid alcohol or other substance use disorder across five significant medical conditions; (2) description of cognitive and behavioral approaches to addressing alcohol and other drug use disorders in medical settings;
(3) a brief overview of the empirical support for CBT approaches for alcohol and other substance use disorders; (4) implementation of CBT in addressing these clinical challenges; (5) implementation of harm reduction approaches to reduce harm caused by substances when abstinence is clinically unfeasible; and (6) a case example that highlights CBT principles and techniques in practice.
Prevalence, Clinical Presentations, and Implications of a Comorbid Substance Use Disorder Among Behavioral Medicine Patient Populations
In this section, we describe the epidemiology and practice implications of addressing alcohol and other substance use disorders across five high volume and/or high burden medical conditions: cancer, HIV/AIDs, hepatitis C, diabetes, and chronic pain.
Cancer. Alcohol use has been linked to an increased risk for developing various types of cancer. Meta-analyses have found that alcohol consumption has been linked to cancer of the mouth, pharynx, larynx, esophagus, liver, female breast, stomach, colon, rectum, and ovaries [27-29]. Further, studies show that the relative risk for developing cancer due to alcohol consumption is associated with quantity of alcohol consumed. For example, Bagnardi and colleagues [27] found that the greatest relative risk of developing cancer occurred for cancers of the oral cavity (i.e., mouth, larynx, pharynx) and esophagus and that the relative risk substantially increased as the quantity of alcohol consumed increased. Specifically, the relative risk of developing cancer of the oral cavity associated with consuming 2, 4, and 8 standard drinks per day was 1.73, 2.77, and 5.75, respectively. In other words, among people who consumed eight standard drinks per day, their relative risk of developing mouth, larynx, or pharynx cancer was nearly six times greater than for abstainers. Similar rates were found by Bagnardi et al. [28] and Rehm et al. [29]. These findings are important given that the rates of an alcohol use disorder among cancer patients is up to five times higher than the general population [30-33].
Alcohol consumption has shown to have a substantial effect on disease progress and mortality for some cancers. Araujo and colleagues [22] found that, among colorectal cancer (CRC) patients, the odds of developing stage III and IV tumors was 2.22 times greater, and the odds of dying were 1.71 times greater, among the patients who consumed alcohol compared to the patients who did not. Maeda et al. [17] found that alcohol consumption was an independent predictor of liver metastases among CRC patients. Findings are similar among patients with lung cancer in that alcohol abuse is associated with increased surgical resection complications, increased risk of postoperative mortality, faster disease progression and worse prognosis [34-36]. The effects of alcohol on breast cancer are mixed. Some studies have found that drinking more than one alcoholic drink per day (i.e., >10 g of alcohol) was associated with a 1 % increased risk of death from breast cancer [37-39]. However, one of the largest pooled investigations examining data from over 9300 breast cancer survivors found no significant associations between post-diagnosis alcohol consumption and breast cancer recurrence or mortality [40].
Last, among patients with cancer, problematic alcohol and/or other substance use has been shown to be associated with increased pain sensitivity [33], difficulties in adequately treating one’s pain [30], limited social supports, and dysfunctional family structures [41] which can negatively affect quality of life and survival [42, 43] and poor treatment adherence [3].
HIV/AIDS. By the end of 2010, the prevalence of HIV in the United States was approximately 1.1 million people. The incidence of HIV in 2010 was approximately 47,745 and injection drug use (IDU) or male-to-male sexual contact in the setting of IDU accounted for 9.7 % of these new infections [44]. Not only are rates of alcohol and drug use, and alcohol and substance use disorders, high among individuals with HIV (at least twice that of the general population; [4, 45, 46]), use of alcohol and other drugs are also associated with an increased risk for HIV infection. Buchacz and colleagues [47] found that HIV incidence among amphetamine users was 6.3 % per year, compared to 2.1 % per year among non-users. Other studies have found that use of “poppers” was associated with increased hazard rates of HIV seroconversion (HR 2.10-3.89; [48,49]). A recent meta-analysis examining the effects of alcohol consumption on HIV incidence found that alcohol consumers were at a 77 % increased risk of HIV infection, those consuming alcohol at the time of or prior to sexual relations were at an 87 % increased risk of HIV, and binge drinkers were twice as likely to become infected with HIV compared to non-binge drinkers [50].
One of the primary reasons for the higher HIV incidence among people who engage in alcohol and substance use is engaging in risky sexual practices due to the disinhibitory effect that alcohol and drugs cause. Mimiaga and colleagues found, for example, that those HIV+ individuals who reported engaging in unprotected anal sex had higher odds of polydrug, marijuana, amphetamine, opiate, and injection drug use. Similarly, they found that unprotected vaginal sex was associated with polydrug and crack-cocaine use [4]. Further, research has found that any alcohol consumption, problematic drinking, and alcohol use in sexual contexts were associated with a 63 % increase, 69 % increase, and a 95 % increase, respectively, in engaging in unprotected sex among people living with HIV/AIDS [51].
Finally, there is substantial evidence demonstrating the various adverse consequences that alcohol and substance use can have on HIV treatment adherence, disease progression, and mortality. Specifically, studies show that alcohol and substance use negatively affects CD4 cell counts, viral load, highly active antiretroviral therapy (HAART) uptake and adherence, healthcare utilization, and liver function [4-12,14,52].
Hepatitis C (HCV). Hepatitis C virus (HCV) is the most common chronic blood- borne infection in the United States with 3.2 million people chronically infected [ 105,106]. Chronic HCV infection is the leading cause of cirrhosis and hepatocellular carcinoma, as well as a primary reason for liver transplantation [53]. Injection drug use (IDU) is the most common route of transmission of HCV in the United States and accounts for at least 70 % of all new HCV infections [54] A recent report demonstrated that each HCV+ person who engages in IDU will infect another 20 people with HCV and that this rapid transmission occurs within the first 3 years of infection [55]. Though injection drug use is most highly related to incidence of HCV infection, non-injection use of other substances (i.e., heroin, crack, cocaine) is also associated with HCV incidence rates of 5-29 %, depending on the substance used, gender, and age [56]. Alcohol use is very common among people with HCV, with rates of heavy alcohol use among HCV patients is nearly eight times higher than the general population (41 % vs. 5 %, respectively; [57]).
Few studies have been conducted to examine the effects of ongoing substance use on the course of HCV disease progression, primarily due to the fact that people who engage in injection drug use do not regularly undergo liver biopsy and are difficult to monitor over time [18]. However, one study examining the natural history of disease progression among people who acquired HCV from IDU found that the relative incidence of developing end-stage liver disease (ESLD) significantly increased as frequency of IDU increased [18]. Moreover, injection drug use is associated with low rates of HCV treatment uptake, with approximately only 1-6 % initiating treatment [15,16]. Alcohol use in HCV has been shown to increase severity and progression of liver disease, increase incidence and prevalence of cirrhosis, decrease effectiveness of interferon treatment, decrease immune response, increase viral load, increase liver fibrosis, and increase treatment discontinuation [58-60]. Generally, given that heavy alcohol use and HCV infection independently are known to potentially cause cirrhosis, when combined together they produce a synergistic effect that hastens liver fibrosis and cirrhosis [18-21]. In fact, Corrao and Arico [19] found that, among HCV-infected heavy drinkers (i.e., consuming between 9 and 12 alcoholic drinkers per day), the risk for developing cirrhosis was 100 times greater than for HCV-infected individuals who did not consume alcohol.
Diabetes. The prevalence of diabetes has increased substantially in recent years [61]. In 2013, an estimated 382 million individuals globally were living with diabetes, and that number is expected to rise to 592 million by 2035 [62]. Substance use, specifically heavy alcohol use, is associated with an increased risk for type 2 diabetes [63]. Although some evidence suggests that mild to moderate alcohol use is associated with a decreased risk for type 2 diabetes [63-65], more rigorous recent research suggests this research was confounded by lack of control of important explanatory variables. Recent studies suggest there is likely no alcohol-related health benefit even from mild-moderate amounts of alcohol consumption [66, 67].
Despite these facts, for patients with diabetes, rates of co-occurring alcohol and other substance disorders are higher among patients with diabetes than the general population. A study by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) reported that, among primary care patients diagnosed with diabetes, 13.4 % met criteria for at-risk drinking, and 11.1 % of these risky drinkers met criteria for current alcohol dependence [68], compared to estimated prevalence rates of heavy alcohol use of 6.3 % in the general population [25]. A review of diabetic young people (age 17-24, mean age 21) using substances found that more than 50 % of participants reported using cannabis (80 %), ecstasy (60 %), and heroin (30 %); 70 % were poly-drug users [69].
Elevated rates of substance and alcohol use within diabetic patients are of particular concern as they are associated with poorer medication adherence, which is essential for maximizing one’s prognosis in diabetes [70]. Consequently, alcohol abuse and dependence is likely associated with increased morbidity and mortality in diabetes, especially given the complications of non-adherence [71].
Non-cancer Chronic Pain. Chronic pain is a widely prevalent and interfering disease and co-occurs with substance use at a high rate [72]. As many as five to seven million patients with a substance use disorder also report pain [73] although this number may not be fully representative of the full population [72].
A significant issue with regard to treating chronic pain, especially among patients with a substance use disorder, is that the opioids used to treat the pain (e.g., morphine, codeine, oxycodone) may be posited as “the problem,” “the solution,” or a combination of both [73]. Patients tend to misuse opioids for a number of reasons that are linked to various implications and consequences. Individuals may misunderstand the correct use of opioids, including using opioids to obtain relief from depressive or anxious symptoms, insomnia, or a host of other symptoms. Additionally, patients dependent on opioids may overuse opioids even once the pain has subsided to reduce withdrawal symptoms [74]. Regardless, if a substance use disorder predominates within a clinical setting, aggressive management of an underlying pain problem is likely to be ineffective if not coordinated appropriately with treatment for the concurrent SUD [73].
Substance use proves to be problematic to individuals living with chronic pain as it has been shown that persons with substance use disorders are less likely to receive effective pain treatment [75]. The stress of a lack of adequate treatment of pain may itself serve as a trigger to relapse to substance use [73]. Along these lines, research has shown that a large proportion of patients with chronic pain underuse their opioid prescription medications [76,77], often citing concerns about adverse effects, particularly addiction [78, 79]. Though little research exists that specifically examines reasons for underuse among chronic pain patients with a history of a substance use disorder, one study found that half of the “under-users” were concerned about addiction which was reflective of their history with substance use disorders [79]. Underuse of medication can leave pain untreated, which, as stated previously, is a potential trigger for relapse. It is therefore important for clinicians treating patients with chronic pain to be aware of whether a patient is in recovery from a substance use disorder in order to anticipate and prevent potential relapse. It is also imperative to discuss the possibility of relapse and associated consequences with patients over the course of therapy, especially when the use of prescription opioids are incorporated within the treatment regimen as they may lead to physical dependency and possible misuse (either overuse or underuse). However, the clinician should also be sensitive not to inadvertently minimalize the patient’s complaints of pain, and see the patient’s willingness to discuss past (or current) substance problems as an opportunity for readiness for change. This will also aid in stigma reduction, harm reduction, and overall patient care [73].
It is important to note that opioid medications tend to be the first-line approach to treating pain. However, research has shown that, patients who continue to take opioid medications at least 2 months post-trauma tend to have higher rates of psychological distress, less effective coping strategies, and higher scores on disability compared to patients who do not take opioids [80].
Given that long-term use of an opioid increases one’s risk of developing physical dependency and misuse/abuse, it is important for a clinician working with patients with chronic pain and a history of a substance use disorder to also consider prescribing psychosocial treatments for pain management, such as CBT or other efficacious skills-based interventions.
In summary, problematic alcohol and substance use is related to a wide variety of negative outcomes, including mortality. However, particularly among medically ill individuals, alcohol and substance use are related to disease acquisition, hastening of disease progression, increased mortality, and poor medical treatment adherence. Consequently, if the underlying substance use disorder can be effectively treated, this would translate to improved disease outcomes. Accordingly, we will now describe a cognitive behavioral approach for the treatment of substance use disorders, with particular attention paid to individuals with a co-occurring medical condition.
