Updated: Jan 16, 2019
by Clinical Director Dr. Leddi Fraser, PH.D
Craving, or the intense desire to reinitiate drug usage is a learned response that has corresponding neurological implications. In general terms, craving is the struggle between the older instinctual part of the brain that is driven toward the acquisition of natural rewards such as nourishment and procreation, and the newer part of the brain that focuses on the inhibition of drives due to potential repercussions. The increased dopamine synthesis and release caused by psychoactive substances significantly heighten sensations that are normally produced by natural rewards, increasing motivation to repeat the experience. On the other hand, some substances appear to impair the function of brain regions that control impulses and behavioral responses, diminishing the individual’s ability to restrain behaviors. Craving has been correlated with the process of withdrawal, the physical reintroduction of the addictive substance, and with external cues or “triggers”. These cues include individuals, locations and items that have been connected with the drug user’s substance of choice. Cue response temporarily increases dopamine levels, which lower when substances are withheld, depressing affect. As well, baseline dopamine levels and mood are often depressed for a significant time period due to diminution of neurons and receptors after protracted substance use. In addition, the inability to cope with “stress, anger and depression” without the use of substances has been found to facilitate craving and relapse (Jaffe & Jaffe, 2004, p. 27; Julien et al., 2008; Goldstein & Volkow, 2002).
Goldstein and Volkow (2002) indicated that memories alone cannot induce craving, but reward motivated excitement or expectancy connected with past recollections appear to be the combination of factors that initiates craving. These authors argued that the frontal cortex is involved in craving. In an fMRI study they conducted, the level of craving experienced by recently abstinent users was linked with corresponding increases in orbitofrontal cortex and striatum activation. Childress et al. (1999) utilized positron emission tomography (PET) in a study exploring the effects of craving on brain structures implicated in cocaine usage. These authors postulated that the physiological symptoms of craving are linked with similar brain response mechanisms evoked during the use of cocaine. “Cerebral blood flow (CBF)” was measured in abstinent cocaine users and control group members. The results of their research indicated that craving only occurred in subjects with a history of cocaine usage. As hypothesized, the experience of craving correlated with the activation of some of the same brain structures stimulated during substance use, including the anterior cingulate, the amygdala and the temporal pole. Although the baseline blood flow in the anterior cingulate was significantly lower in the abstinent cocaine users prior to stimulation, their blood flow levels elevated significantly more than controls following a video depicting features of cocaine use. Baseline amygdala levels were also slightly lower and elevated significantly compared with controls and post stimulation temporal pole levels were higher in subjects than controls. In addition to elevated CBF in these regions, decreased CBF was found in the hippocampus and basal ganglia.
The significance of these findings is based on the function of each of these brain regions. The amygdalae are involved in connecting biologically consequential events with external precipitants and the anterior cingulate is connected with early learning, emotional modulation and motivation. The hippocampus is involved with the translation of facts and experiences into memory and the basal ganglia are connected with the prioritization or selection of behaviors. Stimulation of the amygdala and anterior cingulate, as well as their connection with the nucleus accumbens, suggests that the rewarding sensations elicited by dopamine elevation in the brain are incorporated into learning, motivation, and responsiveness to cues, facilitating a powerful connection to the precipitating stimulus or substance. Reduced CBF in the basal ganglia and hippocampus indicate a potential craving-induced disruption of the ability to control behaviors based on the consideration of known repercussions (Childress et al., 1999; Goldstein & Volkow, 2002; Julien et al., 2008). Goldstein and Volkow (2002) indicate this interaction between the mesolimbic and mesocortical dopamine systems increase craving and diminish restraint through triggering these two systems, evoking emotive memory stimulation, reward expectations and the activation of neurons that synthesize and release dopamine. Childress et al., (1999, p. 15) stated,
The developing brain signature of cue-induced craving is thus consistent with its clinical phenomenology: the drug user is gripped by a visceral emotional state, experiences a highly focused incentive to act, and is remarkably unencumbered by the memory of negative consequences of drug taking.
Berridge and Aldridge (2008) differentiated between “wanting” and “liking” in relation to addiction and craving. These researchers argued that although these two phenomena primarily co-occur within subjective awareness, they are distinguishable events that are controlled by different brain systems. Berridge and Aldridge (2008, p. 625) argued that “wanting” is influenced by the mesolimbic dopamine network and is “the attribution of incentive salience to reward stimuli, which makes them be perceived as attractive incentives.” These researchers further delineated between “conscious” and “core” wanting, suggesting that the wanting most salient to craving is “core wanting” that is less rational, and not fully within consciousness, controlled by “subcortical systems”. These researchers indicate that cues or triggers become attached with a conditioned response through “learned incentive motivation”, which causes cues to almost directly represent the reward, activating an intense desire for both. In addition, a substance-induced sensitization of the mesolimbic system causes long-term susceptibility and heightened activation to these cues as well as increased dopamine release upon substance use. Adding an additional complication is that the “brain mesolimbic dopamine system” is reactive to both stress and reward. Knowing the repercussions of future substance use, not liking the results, particularly when tolerance reduces the “high” or level of enjoyment, diminishes conscious wanting and might induce stress in addicts. The activation of the dopamine system due to a combination of stress, sensitization and core wanting while coping with external triggers significantly influences decision-making. Therefore, Berridge and Aldridge (2008) argue that craving and relapse is not primarily driven by logical choices or conscious wanting, but by a mesolimbic-mediated compulsion.
Strategies To Cope With Cravings:
Smart Recovery, cognitive behavior therapy (CBT), and 12 Step Recovery provides some strategies on how to cope with cravings that individuals often find helpful.
In treatment individuals are prompted to identify their external triggers, which often comprise of people, places, and situations, as well as internal triggers, which typically are emotionally evocative thoughts, leading to uncomfortable or undesirable feelings.
One strategy related to triggers is to avoid or escape the stimuli that is evoking cravings. Our patients are encouraged to connect in with sober supports and peers, rather than re-engaging with people whom they have used substances with before. We also encourage individuals to avoid locations where they have used, or exposure to their substance of choice. If they cannot completely avoid these triggers, we support them in creating an exit strategy, so that if they are triggered, they can quickly leave the vicinity, situation, or the company of another before they relapse.
We also talk about riding out the craving rather than giving in to it immediately. Cravings typically do not last more than 15 minutes if the individual does not ruminate or dwell on them. The analogy that is often used is surfing, where the craving builds up into a crest but then quickly dissipates just like a wave on the ocean. If an individual gives into a craving and uses, typically what happens is that their cravings will increase in intensity and duration, but if they do not give in, then the wave gets smaller and shorter. Just like in surfing, practice makes perfect. If patients ride out the wave, they build efficacy in knowing that they can manage the cravings and that they have the strength to do it.
Another strategy is related to acceptance, which is a concept that is discussed in both 12 Step Recovery as well as Smart Recovery. Acceptance is recognizing that we as humans cannot control everything. There are times when we have to accept uncomfortable experiences or emotions. Knowing that the discomfort is temporary and not something that we can control or judge oneself over often allows individuals to get through cravings.
There are active measures in Smart Recovery that might assist individuals in managing cravings as well. The DISARM and ABC exercises are tools to identify and challenge cognitive distortions, including those that exacerbate cravings. These tools allow individuals to utilize evidence to generate new rational beliefs that will often reduce cravings and foster the perception that the individual can tolerate the craving without giving in to it.
Fun is also an important tool in combatting cravings. In treatment, we encourage patients to begin to rebuild interests and engage in positive sober activities to learn to have fun in abstinence. When a craving occurs, it is an effective tool to redirect attention to other activities that provide fun and pleasure rather than attending to cravings or giving into them. It is crucial to build a list and have access to these activities so that individuals can quickly engage in something that provides pleasure when a craving occurs.