The present study explored the mediator role of stigma between social support and depressive symptoms among SUDs patients by a moderated mediation model, which showed that stigma partially (38.51%) mediated the relationship between perceived social support and depressive symptoms. More specifically, less social support increased depressive symptoms by bringing about higher stigma. We also found that self-efficacy significantly alleviated the effect of stigma on depressive symptoms, suggesting that SUDs patients with high self-efficacy are less affected by stigma.
An exciting finding indicated that the SUDs-related stigma mediates the relationship between perceived social support and depressive symptoms, which confirmed our H1(H1)—in line with previous studies, suggesting that a poor social network could induce severe internalized stigma in schizophrenics [37, 38]. It has been widely reported that social support can be used as a predictor of depressive symptoms and stigma [14, 15, 35, 67, 68]. A study in a population of women infected with Acquired immunodeficiency syndrome (AIDS) found that stigma could mediate the relationship between social support and depressive symptoms [69]. Similar results were also found in substance abuse patients [40]. Therefore, given that the above results indicate that a supportive environment, including equal acceptance of SUDs patients and providing necessary help and care, can help patients build self-esteem and alleviate depression.
On the contrary, a hostile environment can cause SUDs patients to believe that they are primarily responsible for the disease, therefore exacerbating the stigma. This finding highlights the importance of social support for SUDs patients. SUDs patients with reliable social support are accompanied by lower stigma, which can help reduce the mental stress associated with SUDs, such as depression symptoms. Our finding emphasized the necessity to provide more social support for SUDs patients and reduce their stigma. We also found that self-efficacy moderated the relationship between stigma and depressive symptoms, which supported former studies showing that stigma can lower self-efficacy among individuals with alcohol addiction [32]. However, the study results about internet addiction did not prove that self-efficacy could influence stigma [70]. This is inconsistent with our results. The discrepancy could come down to the different samples. We speculate that people with internet addiction would perceive less stigma from their family members and peers than patients with SUDs.
Individuals with a high sense of self-efficacy have strong beliefs to accomplish the goals. Therefore, they are rarely interfering with ed by the negative evaluation of others, such as stigma. The labeling theory proposed by Link et al. could help us further explain this result, suggesting that stigma affects mental health by destroying the evaluation dimension of self-, concept which is mainly related to self-efficacy [71]. Decreased self-efficacy has been shown to weaken personal empowerment, and reduced power can lead to a higher level of depression [72].
Additionally, Bandura. et al. put forward that self-efficacy relieves depressive symptoms in SUDs patients because depression may stem, in part, from conditions that induce a belief that they cannot overcome the difficulties [73]. Hence, Curran. et al. also explain why self-efficacy can be a strong predictor of abstinence [74]. Earlier studies have shown that self-efficacy can reduce the recurrence rate of substance use patients [75, 76]. We speculate that this may be achieved by reducing depressive symptoms.
These findings emphasize that both stigma and social support should be considered when treating SUDs patients with depression. A prior clinical trial applied acceptance and commitment therapy to reduce the stigma on SUDs patients, and the results showed that decreasing the stigma could improve emotions, cognitions, and behaviors [77]. Psychotherapy research found a relatively enduring and robust effect of stigma on well-being, indicating that if therapists wish to maximize the well-being of the people they treat, they must pay more attention to addressing stigma [78]. The social support network is an essential factor that should be considered in reducing SUDs related stigma [37, 38], which can be subdivided into multiple dimensions according to the source (e.g., peers, family) and type (e.g., general support or specific support for abstinence [79]. For example, peers in mutual aid groups are the primary support source outside of the conventional treatment of alcohol addiction [80]. A clinical study explored the efficacy of 12-step group therapy in 121 patients diagnosed with SUDs and mental disorders showing that self-help groups help reduce mental health and the severity of drug abuse symptoms [81]. Another source of social support is family [82]. Family members, such as parents, play a crucial role in helping patients meet basic demands. Good family support could help patients reduce the impact of stigma [37, 38]. However, if the patient brings a high level of stress and tension, which overwhelming the family’s ability to cope, it may lead to reduced family support [83]. Therefore, psychiatrists should pay more attention to increase social support and reduce the stigma of SUDs.
In addition to conventional interventions, doctors should also improve patients' self-efficacy, thereby reducing the adverse effects of stigma on patients and improving mental health. For example, some research has indicated that applying Zen or Tao can resist the urge to drink or take drugs by enhancing self-efficacy [84]. In addition, psychotherapy research, cognitive-behavioral stress management (CBSM) on self-efficacy and relapses into a form of SUDs, shows that CBSM training contributes positively to increasing self-efficacy and lowering the risks of relapse into once again showing SUDs symptoms [85]. A system review that contained 37 interventions on self-efficacy showed that physical activity interventions might be an excellent choice to enhance self-efficacy [86]. Therefore, when treating SUDs patients with high levels of stigma, clinicians can consider encouraging patients to do more regular physical exercises to improve self-efficacy, reducing the negative emotions of drug patients being affected by stigma.
We should not ignore some limitations in the present research. First of all, the study is a cross-sectional study that contains some weaknesses, such as the inability to measure the incidence, difficulty making causal inferences, and making a causal inference [87]. In addition, this study did not control the influence of other confounding variables, for example, whether participants are accompanied by other mental illnesses (e.g., schizophrenia, bipolar disorder, depression, etc.). Moreover, while the model fits patients with drug use disorder, it is unknown whether the result could be expended to other populations, such as alcohol addiction.
Despite these limitations, this study contains some strengths. First of all, this is the first study to explore social support mechanisms affecting depression in a large sample of SUDs patients in China. We also consider the moderating effect of self-efficacy in the mediation model, which was ignored in previous studies [40, 69]. Second, our research established a mediation model and chose a more reliable statistic-1000 bootstrapping, to get robust results. Third, this study also provides some advice for clinical psychiatrists to improve treatment effects.