This study aimed to investigate the effectiveness of ACT in depression and anxiety in people with substance use disorder in Urmia. Based on the results, ACT had a significant effect on depression and anxiety in people with substance use disorders. The present research results showed that ACT was effective in reducing depression in people with substance use disorders in the experimental group. Subjects in the experimental group reported a significant reduction in their depression after receiving the therapeutic intervention compared to the control group. This finding is consistent with the results of previous research (
33,
34). Hemmat et al. (
8) showed that group ACT could effectively reduce anxiety and depression in methadone addicts. Depression is one of the most common causes of dementia in people with substance abuse. This psychological disorder leads to decreased energy levels and interest, persistent guilt, difficulty concentrating, anorexia, suicidal ideation, and changes in cognitive abilities. Drug users also suffer from depression, which adds to their previous problems. People with more depression tend to chew on depressive thoughts. This rumination is often accompanied by the patient trying to find the cause of depression. This will divert the understanding of the current situation (
35).
In this regard, the goal of treatment is acceptance and commitment as an alternative to the four factors of psychological flexibility (fusion, evaluation, avoidance, and reasoning). These alternatives are as follow: (1) accept it as it is, not as they show it; for example, accepting a thought (I am not attractive) only as a thought and not what that thought says (worthlessness); (2) choice: it means that instead of dealing with adverse events, one chooses important and valuable directions and goals in life; and (3) action: it means that after choosing the goals, the person is committed to moving towards them. The basis of ACT is based on the belief that the acceptance of inner experiences is a practical alternative approach to dealing with thoughts and feelings. Acceptance and commitment therapy and other mindfulness-based approaches challenge the idea that inner experiences need to be adjusted to improve psychologically. According to ACT, clients do not have to change their inner experiences to achieve what they want; instead, they are helped to see how trying to control internal experiences is ineffective (
36). Perhaps the reason for the effect of ACT on the symptoms of depression is that this approach targets the functioning of cognitions and emotions rather than the transformation and frequency or situational sensitivity of cognitions. Changing the function of cognition and excitement seems simpler than changing their form and content, perhaps because functional change is more objective than changing the form and content of cognition and emotion, and one can feel in control of the function of cognition and emotion.
The present study results showed that ACT was effective in reducing anxiety in people with substance use disorders in the experimental group. Subjects in the experimental group reported a significant decrease in their anxiety after receiving the treatment intervention compared to the control group, consistent with similar studies' findings (
8,
33,
34,
37,
38). In the present intervention, the concept of acceptance was learned through metaphors and exercises, and the patients were asked to practice acceptance in the face of different situations, especially situations related to their illness, and report the results in sessions. In fact, non-acceptance means that the person seeks to control his inner events (illness, feelings, and thoughts that follow) and causes psychological inflexibility. In each patient, the concept of desire was introduced as an alternative to control and understand related exercises. Being inclined to experiences increased the connection to the present and thus reduced anxiety. Another critical component of ACT is the values. Patients were asked to identify their values, set goals for those values in their lives, and commit to living their lives to achieve those goals based on values. In fact, this part of the treatment helps consumers regain their motivation for life, a rich and valuable life that is primarily the goal of ACT. As a result, patients with substance abuse, by performing cognitive fault drills, were disillusioned with the disease-related thoughts and became less associated with them, leading to anxiety reduction. The self as a context, which is one of the six factors of ACT, is a transcendent sense of self that can be accessed through the processes of mindfulness and cognitive failure (
39). This treatment helped consumers see themselves as independent of their illness, not to identify with the thoughts and feelings of the illness and with their body, or more precisely, with their illness. This was facilitated by the observer practice, which helped the consumer to be merely an observer, an external observer separated from the body, thoughts, and feelings, thus facilitating acceptance as a context.
The current study results indicated that the therapeutic intervention affected other components by affecting psychological resilience. Psychological resilience is the ability to communicate fully with the present as a conscious human being and change or perpetuate behavior in the service of one's worthwhile goals, using the six primary processes of acceptance and commitment therapy: Acceptance, self-failure as a context, connection with the present, values, and committed action. The purpose of acceptance is to reduce the need for thought retention, although it should not be mistaken for tolerance or submission; in fact, with awareness of inner experiences and active acceptance without an attempt to reduce them, clients are empirically confronted with the paradoxical effects of controlling thoughts and emotions, and the difference between the dysfunctional results of controlling thoughts and emotions. Through various metaphors and exercises, clients learn the difference between acceptance and tolerance and practice acceptance skills in complex internal events. With various exercises, they learn to experience intense emotions or pay attention to intense physical emotions without being harmed. Thus, instead of controlling and avoiding the symptoms of anxiety and depression, by changing the context and turning it into acceptance of all internal events, they can be experienced without being harmful (
39). The purpose of this treatment is not to change the signs and symptoms but to change people's relationship with their thoughts and feelings so that they no longer see them as signs. According to a functional context that is the theoretical basis of ACT, the ultimate goal is to change the painful thoughts and feelings of the old problem, the abnormal traumatic signs that prevent a meaningful and rich life into a newer form, and the natural human experiences that are part of a rich and meaningful life. In fact, instead of just focusing on reducing the symptoms, we changed the context in which these disturbing thoughts (symptoms of depression) or avoidance (symptoms of anxiety) occurred, and then we helped them act in a way that is more in line with their values (
36). In an ACT model, addressing empirical needs is not necessarily the client's goal; the goal is to help the client discover and clarify his/her values, and to some extent, to avoid scary situations, and it is argued to some extent that avoiding scary situations may interfere with moving in the direction of values.
Acceptance helps clients choose activities in line with their values and abandon control strategies. In the ACT, setting goals and clarifying values are essential. Values are introduced as a general way of life. Goals and values are the client's own choices. This therapeutic phase serves two practical purposes: First, it encourages clients to choose their own goals and values, and second, it highlights goals that may not be clear (
40). In the field of working with values in this research, clients were also trained to examine their values in different areas and determine their necessity in each area to finally focus on abandoned problems and move in the direction of values, and finally, identify goals in the direction of values. It seems that the present intervention improved the symptoms of depression and other psychological components by affecting the values of addicted people. In general, according to the characteristics of depressed people, which include avoiding or escaping from mixing with depressing thoughts and memories, trying to control thoughts and feelings, cognitive fusion, ruminating and repetitive thought patterns, negative cognitions, self-underestimation, pursuit of inconsistencies with values and mistakes in the pursuit of value goals, intervention based on ACT in the present study could help clients change the initial avoidance patterns, increase full acceptance of a wide range of objective experiences, improve quality of life and flexibility, change judgments, eliminate the power of depressive thoughts, reduce rumination, gain a sense of change, and identify their goals and values, which are effective in depression reduction in these people.
This treatment first tries to increase the person's psychological acceptance of mental experiences (thoughts and feelings) and reciprocally reduce ineffective control practices. Clients are taught that any action to avoid or control these unwanted mental experiences is ineffective or has the opposite effect and exacerbates them and that these experiences should be accepted without any internal or external reaction to eliminate them entirely. In the second step, the person's psychological awareness is increased in the present moment; that is, he/she becomes aware of all his/her mental states, thoughts, and behavior in the present moment. In the third stage, the person is taught to separate him/herself from these mental experiences (cognitive fault) so that he/she can act independently of these experiences. Fourth, the therapy tries to reduce the excessive focus on the visual self of the personal story (such as being a victim) that one may create in mind. Fifth, the therapy helps the individual to know and clearly identify his/her personal values and turn them into specific behavioral goals (clarifying values), ultimately motivating him/her to take committed action, that is, to work towards specific goals and values. That is, to work towards specific goals and values along with accepting mental experiences, these mental experiences can be depressive, anxious, obsessive thoughts, etc. This method increases the effectiveness due to its underlying mechanisms such as acceptance, awareness-raising, desensitization, presence at the moment, observation without judgment, confrontation, and release while reducing the symptoms of depression and anxiety (
41).
In general, the present study focused on the effectiveness of ACT on depression and anxiety in people with substance use disorders. According to this research, ACT reduced depression and anxiety in people with substance use disorders. As a result, it can be inferred that emotional control strategies, behavioral commitment exercises, value clarification, failure, and acceptance can reduce depression and anxiety in substance abusers. The purpose of the study was to help people who were suffering from psychological problems in addition to substance abuse. As a result, this training helped them accept their thoughts and commit to making changes. In this treatment program, addicts were helped to recognize the nature of the inefficiency of their disturbing thoughts and ultimately move towards their values.
One of the limitations of this study was the lack of a follow-up due to time constraints for measuring the effectiveness of this approach after treatment. Another limitation was using self-reporting tools (questionnaires) to measure depression and anxiety, which may have made patients present a good image. In general, despite the existing limitations, due to the effectiveness of this therapeutic approach, a practical step in this study was taken to improve the psychological problems of people with substance abuse. Due to the mutual relationship between mental health and physical health, the favorable mood of people with substance abuse could help them reduce their consumption and encourage them to quit. It is suggested that the effectiveness of ACT in depression and anxiety be compared with other third-wave therapies, including metacognitive therapy, dialectical behavior therapy, meta-diagnostic therapy, mindfulness therapy, etc. Also, due to the positive effect of ACT on reducing depression and anxiety symptoms in people with substance use disorder, it is suggested that this program be used to treat substance use disorder.