Do motives for substance use during methadone treatment vary by substance type?

The reasons underlying alcohol use – such as coping with unpleasant feelings and enhancing pleasant experiences – have been widely studied, offering insight into common motives for drinking among the general population. It is unclear if the reasons underlying alcohol and other drug use differ according to substance type. Given the importance of characterizing motivations for substance use to inform treatment and recovery, this study investigated whether drug class plays an important role in the motives that drive different types of substance use during methadone treatment.

WHAT PROBLEM DOES THIS STUDY ADDRESS?

Research on individual motives for alcohol use has identified four broad motives, including drinking to enhance positive moods (internal approach motivations), drinking to cope with negative internal states like negative emotions (internal avoidance motives), drinking to improve social interactions and gatherings (external approach motives), and drinking to conform to social pressure or a desire to fit in (external avoidance motives). Though the motives for alcohol use are well characterized, this area of study has largely focused on healthy populations without alcohol use disorder or other substance use disorders. This literature is also lacking research on the motives underlying use of other substances and it is unclear if the major motives identified for alcohol differ from those of other drugs. In addition, little is known about motives underlying polysubstance use despite many individuals with addiction engaging in the use of more than one substance. Given that motives are thought to be one of the key contexts to a personalized understanding of someone’s substance use, characterizing motives for using substances, particularly in clinical substance use disorder populations, can help inform new drug use prevention, intervention, and treatment strategies. One of these clinical populations that are important to examine are individuals who are receiving methadone treatment for opioid use disorder, because methadone is an effective treatment that addresses the motives underlying opioid misuse but does not directly target other substance use. Identifying motives for other substance use might help inform new therapies that address non-opioid substance use, while methadone helps to address opioid misuse, so that patients engaged in polysubstance use can achieve recovery. To better characterize motives for drug use and identify whether motives differ across various drug types, this study evaluated common motives for engaging in the use of various substances among individuals who recently used substances and were receiving methadone treatment for opioid use disorder.

HOW WAS THIS STUDY CONDUCTED?

This study was a survey-based investigation of 138 individuals who were receiving methadone treatment for opioid use disorder and had engaged in substance use within the past 30 days. Participants were recruited from four methadone clinics in Halifax Regional Municipality and Montreal, Canada between 2015 and 2016. Participants completed a novel brief questionnaire (called the polysubstance motives measure) of motives underlying the use of 6 substance categories: (1) tobacco/nicotine, (2) alcohol, (3) cannabis, (4) stimulants, (5) opioids, and (6) tranquilizers. The questionnaire was developed by leveraging and adapting the four-factor motivational model, the Drinking Motives Questionnaire-Revised, and the Marijuana Motives Measure. The Questionnaire consisted of 7 items addressing 7 motive dimensions: (1) enhancement, (2) social, (3) conformity, (4) coping with depression, (5) coping with anxiety, (6) expansion, and (7) coping with withdrawal (see the figure below, which shows the motive dimensions and their corresponding questionnaire items). Participants rated the frequency of each motive’s contribution to their past 30-day use of each substance on a scale from zero (never) to ten (always). The researchers examined whether ratings for these 7 motives varied by drug categories. Motives were also ranked within each drug category from the most to least frequently endorsed, as a proportion of substance use occasions over the past 30 days.

The study sample primarily consisted of mostly white individuals (80%), two-thirds of whom were men (66%) in their early-forties (mean age: 40 years). About half of the sample was employed and all participants had attended their methadone clinic for 30 or more days prior to participating in the study. On average, participants were receiving 79 mg of methadone per day and reported using a median of 3 drug types in the past 30 days.

WHAT DID THIS STUDY FIND?

Enhancement motives were ranked highly for all substances, with this motive being most strongly endorsed for stimulants.

“Enhancement” was ranked as the number 1 motive for use of stimulants and was one of the top 3 motives for use of all drugs except tobacco (ranked 4th). When drugs were examined for differences, enhancement motives for using cannabis, stimulants, and opioids were more strongly endorsed than enhancement motives for tobacco and tranquilizer use.

Coping with withdrawal was reported as the most frequent motive for opioid use and the dose of methadone received influenced endorsement of this motive.

Coping with withdrawal symptoms was ranked as the number one motive for use of opioids, which was ranked higher for this motive than all other substances. Withdrawal management was also endorsed more greatly for cannabis, tobacco, and tranquilizers relative to alcohol and stimulants. When the authors looked at the influence of methadone dose on motives for opioid use, higher methadone doses were associated with a reduced likelihood of withdrawal symptoms being reported as a motive for opioid use.

In general, social motives and conformity were not highly ranked reasons for substance use.

Conformity was ranked as the least endorsed motive for use of all substances and did not differ by substance type. Social motives for substance use were ranked toward the middle of the pack for all substances (4th or 5th). When substance categories were examined for differences, social motives were more strongly reported for cannabis relative to tobacco and tranquilizers.

Coping with anxiety was ranked as the number one motive for use of most substances, except opioids and stimulants, and was most strongly endorsed for tranquilizer use. Coping with depression was ranked as one of the top three motives for use of all substances but was most strongly endorsed as a motive to use opioids, followed closely by cannabis and tranquilizers.

Coping with anxiety was ranked as the number 1 motive for use of tobacco, alcohol, cannabis, and tranquilizers. When drugs were compared for significant differences, coping with anxiety was less frequently reported as a motive to use stimulants, compared to all other substances. Moreover, coping with anxiety was more greatly endorsed as a motive for tranquilizer use relative to alcohol, cannabis, stimulant, and opioid use.

Coping with depression was ranked as the second or third motive for all substances. For most substances, coping with depression was endorsed similarly to coping with anxiety as a motive for use, except for tobacco and tranquilizers for which coping with depression was reported as a less frequent motive. Coping with depression was more strongly endorsed as a motive for opioid and cannabis use when compared to tobacco and stimulants. It was also reported as a more frequent motive for tranquilizers compared to stimulants.

Though expansion motives were ranked low for all substances except stimulants, greater endorsement was observed for cannabis, stimulants, and opioids relative to alcohol, tobacco, and/or tranquilizers.

Expansion was ranked as the sixth most frequently reported motive for all substance use except for stimulants, for which this motive ranked third. Expansion motives were more greatly endorsed for cannabis and stimulant use relative to alcohol, tobacco, and tranquilizer use. This motive was also more greatly endorsed for opioids compared to tobacco and tranquilizers.

Table 1. The table above depicts the rankings for motives (shown in the far left column), within each drug class (shown in the top row). The most strongly endorsed motive was (1) coping with anxiety for alcohol, cannabis, tobacco, and tranquilizers, (2) coping with withdrawal for opioids, (3) and enhancement for stimulants. The least frequently endorsed motive was conformity for all substances.

WHAT ARE THE IMPLICATIONS OF THE STUDY FINDINGS?

Studies like this help us better understand the reasons underlying substance use among methadone patients. This can ultimately help inform new substance-specific strategies for preventing a return to substance use and promoting successful treatment, by targeting motives for use and addressing/preventing maladaptive behaviors in response to various motives. This study found that the motives underlying alcohol and other drug use among individuals receiving methadone treatment for opioid use disorder do indeed vary according to the substances in question. This is important because, although methadone is an effective treatment, it specifically targets receptors in the brain that bind opioids and does not directly target other substance use. Thus, people seeking recovery who use both opioids and non-opioid substances may be able to stop using opioids as a result of methadone treatment but their use of other substances could continue without addressing the motives that drive the use of these other substances. Identifying motives for other substance use might help inform additional therapeutic methods for addressing concomitant substance use disorders to better support patients receiving methadone treatment.

These results suggest that targeting withdrawal symptoms and motivation to misuse substances as a result of withdrawal may be particularly important for preventing opioid use among methadone patients, but are less important for other substances.

A higher dose of prescribed methadone was also associated with less withdrawal-associated motives to use opioids. This finding is consistent with is known about the importance of dose when it comes to opioid use disorder medication, not only for withdrawal mitigation but also for effective treatment and positive recovery outcomes (e.g., reduced illicit opioid misuse occurs with greater than 60 mg of methadone).

Coping with negative emotions was a common motivator for use of most substances. More specifically, coping with anxiety was the most greatly endorsed motivator to use tranquilizers, alcohol, cannabis, tobacco, and, to a somewhat lesser degree, opioids. A particular bias was seen for tobacco and tranquilizers, for which coping with anxiety largely outranked all other use motives. However, stimulants were much less often used due to anxiety-related motives, which is consistent with stimulant’s physiological effects (e.g., increased heart rate) that often increase anxiety-related symptoms, as well as prior research findings in other treatment samples (e.g., inpatient populations).

Enhancement motives might be particularly relevant for addressing stimulant misuse, given that other motives emerged as substantially less important contributors to the use of this substance. This is consistent with the pleasure and excitement sought with enhancement motives and offered by stimulants’ effects. For cannabis, alcohol, and opioids, both enhancement and coping with negative emotions (anxiety and depression) appear to play similarly important roles in driving their use. This overlap in motives between substances offers opportunity to address the use of multiple substances with a single strategy or approach.

Given the important role of one’s social circle in recovery outcomes, the relatively limited role of social motives and conformity in substance use here may seem counterintuitive. However, the survey item concerning social motives in this study emphasized the role of substances in enhancing one’s own sociability and enjoyment of social gatherings, as opposed to peer influence on use of a given substance. Furthermore, this was an adult sample and the influence of peers often plays a more significant role in substance use and initiation in youth and younger adults, emphasizing age as another important factor when considering the reasons underlying drug and alcohol use.

Interestingly, conformity and social motives showed the least variability across different substances used by a given individual, suggesting that these external motives might be trait-like motivations that tend to be stable in individuals regardless of drug type. Alternatively, enhancement, expansion, as well as coping with negative emotions and withdrawal showed greater variability by substance type within a given individual, suggesting these internal motives may be more state-like, changing according to the substance in question.

Given the variety of ostensibly “self-medicating” reasons attributed to continued use of alcohol or other drugs among these methadone patients, clinical interventions that are designed to redress these challenges, such as mindfulness-based cognitive-behavioral relapse prevention therapies, might be helpful to implement to boost these patients’ non-chemical coping strategies. This may give methadone patients a potentially less hazardous and salubrious option if they want to reduce or refrain from use of these other substances.

LIMITATIONS

1. This study focused on a population of individuals undergoing methadone treatment for opioid use disorder and additional research is needed to determine if these findings apply to other clinical populations using other medication treatments (e.g., buprenorphine) and who have other primary substance use disorders (e.g., stimulant use disorder). This study was also conducted in Canada and it is unknown if outcomes would apply to other countries with different treatment infrastructures and/or sociocultural milieus.
2. Motivations for substance use were evaluated during the early stages of treatment and motivations identified here may not apply to those that underly a return to substance use after long term treatment and abstinence from substance misuse.
3. Not all classes of drugs were examined here (e.g., hallucinogens, designer/club drugs), demanding further investigation to determine motives underlying additional substance use. The majority of participants were white males and it is unclear if findings would apply to individuals with other gender or racial/ethnic identities.

BOTTOM LINE

Studies like this may help us better understand motives for substance use during addiction treatment, which can help inform substance-specific and substance-general interventions that target motives potentially driving ongoing substance use and relapse during and after treatment. This study found that motives for recent substance use in patients receiving methadone for opioid use disorder treatment varied by the type of substance. For stimulant use, enhancement appeared to be a particularly important motive, with other motives being less frequent contributors to use. For alcohol, cannabis, and opioids, coping with negative emotions (anxiety and depression) and enhancement motives both emerged as frequent contributors to their use. Importantly, withdrawal symptoms were the most common and substantial motive for opioid misuse, with lower daily doses of methadone increasing the occurrence of this motive for opioid misuse.

CITATIONS

Mahu, I. T., Barrett, S. P., Conrod, P. J., Bartel, S. J., & Stewart, S. H. (2021). Different drugs come with different motives: Examining motives for substance use among people who engage in polysubstance use undergoing methadone maintenance therapy (MMT). Drug and alcohol dependence, 229, 109133. doi: 10.1016/j.drugalcdep.2021.109133