From what we know, this is the first study to investigate the relationships between resilience and impulsivity, cognitive function as well as emotion among METH-dependent patients during protracted METH withdrawal. We primarily found that high levels of resilience are associated with lower degrees of impulsivity and cognitive impairments and a lower level of depression. Early intervention to provide drug addicts with tools to encourage resilience is essential.
Cognitive functions will generally be impaired in patients addicted to drugs [33, 34]. The cognitive impairment will seriously affect the rehabilitation treatment for METH-dependent patients, especially during withdrawal. Therefore, it is necessary to find a way to improve cognitive deficit in METH dependence patients undergoing withdrawal. This study shows the relationship between high level of resilience and good cognitive function in METH dependent patients during protracted withdrawal, which indicated that psychological resilience might enable a breakthrough. Such data infers that METH-dependent patients with relatively high resilience may have improved delayed memory and attention. Understanding the impact of mental resilience on cognitive function impairment is relatively limited at this stage, and there is little direct evidence on their relationship. Despite this, the correlation can be broadly understood using the cognitive reserve hypothesis. Cognitive reserve is the ability to maintain cognitive function even if the brain injury occurs [35]. Harmonious relationship can improve cognitive reserve, and continuous positive stimulation can enhance the prevalent development of nerve tissue, promote new nerve pathways generation, and compensate for neurocognitive function impairment[36]. Generally, people with good mental resilience can better deal with situations, creating a supportive psychological environment and promoting cognitive function. In contrast, people with low mental resilience levels cannot quickly restore balance when facing adverse events and exist in a state of chronic stress[37], such as protracted withdrawal. Chronic pressure can induce dendrites of the medial prefrontal cortex and hippocampal vertebral body neurons to retract, thereby causing damage to spatial memory and learning ability[38, 39]. Additionally, chronic stress can reduce brain-derived neurotrophic factor (BDNF) in the brain, affecting the memory processing by the hippocampus[40].
During early withdrawal, drug abusers will show a high frequency of impulsivity[41]. However, few studies have explored impulsive behaviors during the protracted withdrawal. The current study also found the connection between resilience and impulsivity during the protracted withdrawal. Although impulsivity may be a pre-existing characteristic that makes an individual prone to start taking drugs, it may also be a consequence of drug abuse[42, 43]. Previous METH use may cause changes in the brain, which in turn has a long-term impact on the changes within the typical decision-making process framework[44]. Thus, during the protracted withdrawal, METH users will show varying degrees of impulsivity. Many studies have investigated the relationship between resilience and impulsivity[45, 46]. The negative correlation between resilience and impulsivity in the period of protracted METH withdrawal may be explained by interconnections between specific neural circuits associated with resilience and impulsivity. The activation of ventromedial prefrontal cortex (vmPFC) has something to do with the promotion of resilience in response to stress[45]. Besides, impulsivity is inversely correlated to gray matter volume in the vmPFC[46, 47]. Thus, we inferred that long-term effect of METH abuse during the protracted withdrawal may result in abnormal activity or volume in vmPFC. High level of resilience may enhance the repair function of vmPFC and reduce the impulsivity[48].
What’s more, the relative higher resilience was associated with lower degree of depression during protracted withdrawal. And the three dimensions of CD-RISC (hardness, strength and optimism) were all negatively related to SDS scores. The result was in line with previous research that resilience is correlated with the symptoms of depression[38] and high scores of mental resilience correspond to lower depressive symptoms[49]. However, the main underlying connection was still unknown. Even though, the possible mechanism can be explained as follows. Wang et al. found that resilience was negatively associated with perceived stress and depression[50]. And several studies suggested that perceived stress was positively correlated to depression in drug users[51, 52]. Perceived stress is defined as an individual’s cognitive assessment of their stress level[53], and effective stress management play a vital role in reducing the degree of depression in drug users[54]. In general, the perceived stress on drug users’ depression depends on their processing ability, while resilience is a coping ability, constantly adapting and rebounding in unfavorable environments. Compared with people with poor resilience, those with good resilience tend to feel less stress under challenging environments and are more likely to overcome stressful situations. Furthermore, when adjusted to a stressful environment, the symptoms of depression will naturally diminish. As for METH-dependent patients, we know, symptoms of depression usually coincide with substance use and withdrawal[55]. Besides, the craving for drugs is related to depression[56]. Thus, it’s crucial to cultivate an individual’s resilience in order to better deal with the symptoms of depression caused by a stressful environment.
Drug addiction is a complex process in which stress plays a crucial role[57]. Addiction and stress responses have a common neurobiological pathway that can be altered by environmental stressors[58]. Even after a long period of abstinence, it is easy to fall back into drug-seeking situations after a stressful experience[59]. Besides, the symptoms appeared in the withdrawal may add difficulties of intervention. Resilience refers to the relative protection of individuals against stress. Therefore, the current study postulated that improving resilience was necessary. For drug addicts, the barriers to resilience may include an imbalance between work and personal life, excessive exposure to stressful events, insufficient time and space to deal with negative emotions, and social isolation[60]. Effective interventions promoting resilience should ideally positively impact one or more of these barrier features, which may be available from the following three strategies. Firstly, training, experience, and perception seem to be essential for enhancing resilience. For example, METH addicts can learn "mindfulness", which focuses on the present mental process, to avoid irrelevant, harmful external stimuli. Secondly, social support appears to be protective. When social support is lacking, METH users may choose to escape and become muffled. Thus, establishing a correct concept of interpersonal communication is an excellent to obtain social support, because it is the basis for establishing good communication between people. Finally, effective coping styles may affect social adaptation in drug addicts, enabling them to become re-engaged with society[61]. For example, teaching stress management for drug addicts. Besides, this study found that the scores of SDS had a significant negative effect on resilience. Another way to increase an individual’s resilience level may be to improve the symptoms of depression. All in all, compulsory isolation of drug treatment centers can ensure that drug users are well-trained, thereby improving their adaptability and providing support designed to encourage better coping skills. Some combination of all or some of these strategies will increase the likelihood of more successful rehabilitation of METH-dependent users and may reduce the probability of relapse.
Some limitations of this research to be considered are that the sample size is relatively small and it will be increased in future research. Secondly, this survey was a retrospective study and did not rule out recall errors and observer bias. Thirdly, the causality cannot be confirmed in this research. In the future, we will explore the direction of cause and effect. Fourthly, certain pre-abstinence factors (for example, early stressful life events) which might predict future recovery or deterioration were not evaluated. Finally, only male METH-dependent patients were participants, and so female METH-dependent patients will be investigated in the future.