Although loss of control over drinking is central to anecdotal accounts of alcoholics’ impaired ability to control their drinking once they have started or to stay stopped from drinking for intended periods of time as this excellent review suggests “Impaired control, defined as “a breakdown of an intention to limit consumption” (Heather et al. 1993; p. 701) has historically been considered an important aspect of addiction. Despite recognition of its importance to addiction and potential value as an early indicator of problem drinking risk, we argue that impaired control over alcohol use has not received sufficient research attention.”
We agree completely with the assertion that this most fundamental aspect of alcoholism and addictive behaviour generally as received scant attention in research over the decades namely because scientists have not been sure which parts of the brain may be responsible for this loss of control.
In recent decades, the insular cortex has been suggested to be instrumental to how well an individual can “read” if they have had enough and how this acts as a signal for future behaviours.
In simple terms if the insula is impaired, it may not properly read out our physiological need, whether current consumption has met that need (whether we have had enough) or the effects this continued consumption will have on future consequence.
The insula and it’s involvement in letting us know when to stop is the most likely candidate in the loss of control phenomenon that exists in alcoholism and addictive behaviours more generally.
Here we borrow widely from this review (1).
“We discuss briefly two potential mechanisms that may help to explain why some drinkers experience impaired control while others do not: neurobiological dysfunction and family history/genetics.
Impaired control over alcohol use involves “a breakdown of an intention to limit consumption” (Heather et al., 1993). Difficulty adhering to limits may be manifested as failure to avoid alcohol use completely (i.e., persistent desire or unsuccessful efforts to cut down or control use [“quit/control”]) or to control alcohol consumption once it has begun (i.e., use in larger amounts or for a longer period of time than intended [“larger/longer”]) (Kahler et al., 1995)… impaired control is a pattern of alcohol use that supersedes conscious intentions to limit use on specific occasions (Heather et al., 1993). Impaired control has been viewed historically as an important aspect of addiction (see Kahler et al., 1995). Its continued clinical relevance is reflected in the fact that two criteria for substance dependence in the 4th edition text revision of the DSM (DSM-IV-TR, APA, 2000) relate to two main facets of impaired control: “larger/longer” (LL) and “quit/control” (QC) (Hasin and Beseler, 2009). More frequent endorsement of LL than QC (e.g., Saha et al., 2007) can be taken as evidence for distinctness of the two main facets of impaired control. However, psychometric findings suggest impaired control is essentially a unitary construct (Heather et al., 1993; Kahler et al. 1995; Read et al., 2006; see Leeman et al. 2012 for discussion).
Evidence suggests impaired control is one of the earliest-developing signs of problem drinking and thus has value as a characteristic of alcohol dependence and potential predictor of more serious problem drinking (see Leeman et al., 2012). Adolescent (Gelhorn et al., 2008; Martin et al., 2006) and young adult (Patock-Peckham et al., 2001; 2011) drinkers frequently endorse impaired control.
Further, alcoholic adults often cite impaired control retrospectively as the dependence symptoms that developed earliest (Langenbucher and Chung, 1995). Limited prospective results show that impaired control predicts subsequent alcohol involvement and related problems.
Discussion of impaired control as an early-developing dependence characteristic implies progression along a continuum of severity (Heather et al., 1993; Heather 1995). This progression may parallel the impulsivity-to-compulsivity shift that has been described in the addictions (Everitt et al., 2008). People may initially have difficulty adhering to limits because they feel compelled to drink even if negative consequences are possible (i.e., impulsive use), due to rewarding effects of alcohol. After a long period of use, people may shift to a habitual pattern in which they feel incapable of stopping even if serious problems may occur (i.e., compulsive use) (Modell et al., 1993).
…enhanced response to alcohol compared to control beverage taste cues in several regions, particularly the insula, precentral gyrus and putamen. Notably, activity in all three regions was associated with riskier task performance in another study (Claus and Hutchison, 2012). Another research group found that alcoholic patients showed decreased activation in the insula and other prefrontal areas in response to fearful facial expressions. Moreover, negative correlations were found between self-reported impaired control and strength of connectivity between the insula and areas of the brain involved in emotion regulation (e.g., inferior frontal cortex) during observation of fearful facial expressions (O’Daly et al., 2012). Taken together, these findings could mean that impaired control is associated with heightened responsiveness to alcohol cues, along with insensitivity to aversive stimuli and these tendencies may be partially mediated by insula dysfunction.
The aforementioned impulsivity-to-compulsivity shift that characterizes addiction has been linked to a change in predominance from cortical to striatal activity and within the striatum, from primarily ventral to dorsal activity (Everitt et al., 2008). A relationship between self-reported impaired control and activity in the putamen (located in the dorsal striatum) in the presence of alcohol cues may be suggestive of compulsive alcohol use among some heavy drinkers with impaired control (Claus et al., 2011a).
… it is well-established that those with a positive family history are at increased risk for developing alcohol use disorders (e.g., Bucholz et al., 1996). There is also precedent for a link with self-control difficulties. Constructs like impulsivity share a common genetic liability with substance use disorders (Kendler et al., 2003). Given this precedent, family history positive individuals may also tend toward impaired control over alcohol use.”
We will be returning to the issue of impaired control in the following blogs.
If science continues to match insular cortex activity to alexithymia, loss of control, risky decison making, lack of insight about future consequence and emotion dysregulation, it may be one of the likely brain impairments which intiate and maintain addictive behaviour.
This the importance of this type of research hardly needs reinforcing.
- Leeman, R. F., Beseler, C. L., Helms, C. M., Patock‐Peckham, J. A., Wakeling, V. A., & Kahler, C. W. (2014). A brief, critical review of research on impaired control over alcohol use and suggestions for future studies. Alcoholism: clinical and experimental research, 38(2), 301-308.