The Effects of Substance Abuse on Memory and Decision Making

The following is a brief analysis of research studies that have attempted to explain the effects of substance abuse on both memory and decision making. A short summary of each area will be covered as well as the possible implications of the finding on psychology and mental health fields. Finally, overall implications, as well as any specific aspects, uncovered within the studies that may be included in future practice.

Memory

According to Galotti (2017, p. 3), memory is the storage and retrieval processes of cognition. The studies assessed specifically focus on the encoding processes involved in forming memories as well as the retrieval or reactivation processes that allow memories to be recalled. The first study focusses on blackouts associated with extreme alcohol intoxication, particularly fragmentary, or partial, and en bloc, or total blackouts. En bloc blackouts are defined by their specified and noticeable start and finish and characterized by permanent amnesia for all events that occur during the interim (Hartzler & Fromme, 2003). Conversely, fragmentary blackouts are less defined and are the result of retardation of the functions associated with the frontal lobe (Hartzler & Fromme, 2003). Working memory seems to be the most affected type of memory in fragmentary blackouts, likely due to the affected prefrontal cortex (Galotti, 2017). Additionally, Hartzler & Fromme (2003) found that there was a significant link between en bloc blackouts and the use of other illicit drugs in addition to alcohol. The resulting interim amnesia remained permanent throughout the course of the study and follow-up (Hartzler & Fromme, 2003).

Conversely, Gisquet-Verrier & Le Dorze (2019), studied the hyperactivity of reminders associated with memory recall and the blocks to memory reconciliation. They compared the similarities and differences between post-traumatic stress disorder (PTSD) and substance use disorder (SUD) and found an extreme number of similarities in their presentations. However, a stark difference was noted in that substance use disorder the likelihood was that the specific events associated with the disorder occurred in the positive, unlike the negative, traumatic events typically associated with PTSD (Gisquet-Verrier & Le Dorze, 2019). Regardless, there was an interesting correlation between the reactivity of seemingly innocuous reminders, triggers not directly associated with the substance use event, and the intensity of cravings (Gisquet-Verrier & Le Dorze, 2019). Intense emotions were also noted and validated by increased activity in the amygdala area of the brain (Gisquet-Verrier & Le Dorze, 2019).

The reminders showed increased activation in the prefrontal cortex (Gisquet-Verrier & Le Dorze, 2019). The study posits that the dysfunctions are the result of abnormal learning and memory processes (Gisquet-Verrier & Le Dorze, 2019). To offset these deficits, the authors suggest that prolonged exposure therapy can produce new pathways within the brain to form connections between new reminders and the areas of the brain most affected (Gisquet-Verrier & Le Dorze, 2019). As an alternative to drug therapies, this study shows promise for some SUD suffers.

Decision Making

As mentioned previously, en bloc blackouts resulting in retardation of the frontal lobes of the brain, specifically the prefrontal cortex (Hartzler & Fromme, 2003). Therefore, it should come as no surprise that this retardation in function of the prefrontal cortex can result in complications with executive functions, such as decision making (Galotti, 2017). Delibas, Akseki, Erdogan, Zorlu, & Gulseren, (2017) describe poor decision making as “deciding against one’s best interests and inability to learn from previous mistakes, with repeated decision leading to negative consequences,” (p. 315). As such, it is no surprise that substance use that has at least some effect on the prefrontal cortex would result in not only a decrease in decision making at the time, but could potentially have a lasting effect on the ability to make rational and positive decisions in the future (Delibas, Akseki, Erdogan, Zorlu, & Gulseren, 2017).

The study used the Iowa Gambling Task and the Barratt Impulsiveness Scale. They did note that while cannabis is the most popular illicit drug in most of the industrialized world, it still contains a number of chemical compounds that have an acute negative effect on the impulse regulation areas of the brain (Delibas, Akseki, Erdogan, Zorlu, & Gulseren, 2017). The study specifically targeted individuals who were identified as ‘long-term abstinent’, these participants had previously been identified as cannabis dependent but had been abstinent for a minimum of 1 month (Delibas, Akseki, Erdogan, Zorlu, & Gulseren, 2017). The reason this is significant is that the study shows that decision-making abilities are still affected even after cessation of drug use. This reiterates the impact of immediate gratification on long-term consequences (Delibas, Akseki, Erdogan, Zorlu, & Gulseren, 2017).

Conversely, Biernacki, et al. (2015), tested the hypothesis that somatic markers caused by the reward and punishment aspect of making decisions illicit abnormal emotional responses. Further that these abnormal responses interfere with arousal (Biernacki, et al., 2015). In this study, opiate users in a treatment program and a control group were evaluated using the Iowa Gambling Task and skin conductance responses were recorded. Unlike Delibas, Akseki, Erdogan, Zorlu, & Gulseren (2017), there was no significant difference found between the opiate user group and the control group (Biernacki, et al., 2015). What these authors suggest is that this is due to the type of treatment that opiate users receive, most typically an opiate blocker and lower dose opiate to reduce or eliminate cravings (Biernacki, et al., 2015). Further studies on post-treatment participants are suggested in the conclusion of the study.

Applications for the field of Psychology

As these studies have shown, substance abuse can and does have a direct link to impairments in memory, both formation and recall, and decision-making abilities. Clients seeking psychological assessment and treatment will likely have to accept that in some cases, specifically en bloc blackouts, there are likely memories that can never be accessed. In cases where trauma or similar situations occurred while the client was under the influence of some substance, there is likely to be symptoms like those associated with post-traumatic stress disorder. In especially tragic situations, extreme depression and feelings of helplessness, guilt, and even suicidal ideation are areas clinicians need to be specifically aware.

These can be present even in situations where memory is not affected, but the consequences associated with poor decision making has occurred. Many individuals suffer substantive psychological distress from actions resulting from poor decisions. Mental health professionals need to be well versed in dealing with such situations as to assist their clients in finding the best way to move forward, through acceptance and understanding.

Conclusion

In summary, the studies included have shown that substances, specifically alcohol, cannabis, and opiates may have a significant impact on memory and decision-making abilities. This is likely a result of decreased function associated with the frontal lobes of the brain, specifically, the prefrontal cortex. Additionally, the impact of substance use can last an extended period, permanently in the case of en bloc blackout associated amnesia. Finally, clinicians need to be aware of the extenuating conditions and comorbidities associated with substance use and the associated substance use disorder.