Introduction

If a person has a recognizable mental, behavioral, or emotional disorder during the past year that leads to a significant functional impairment in one or more of his daily activities, he is called a chronic mental patient. The most common diagnoses of chronic mental disorders that cause serious impairment of occupational performance include schizophrenia spectrum disorders, bipolar disorders, and major depressive disorders. Psychological symptoms cause the deviation of mental, emotional, social, perception, cognitive, thinking, and motor functions, which are required to participate in daily activities and provide mental health to humans [1]. Lack of motivation changes lifestyle routines increases self-harming behaviors, and decreases mobility and physical activity leading to substance dependence, obesity, and following an unhealthy diet [2]. These people experience homelessness, lack of employment, arrest more than others, and cause huge economic and social costs to society. They also have a shorter life expectancy. The unwillingness of chronic mental patients to participate in daily activities has destructive effects on their autonomy and self-identity and reduces their quality of life. However, people with chronic mental disorders can still manage their chronic symptoms and engage in a healthy and meaningful life. Positive mental health is seen in people who participate in social and productive activities, face daily demands, and participate in society [1].
Assertive community treatment, supported employment, cognitive behavioral therapy, family-based services, token economy, skills training, psychosocial interventions for alcohol and substance use disorders, and psychosocial interventions for weight management are eight evidence-based interventions recommended for long-term hospitalizations or residential care where most people live with chronic mental illness. Among these, the token economy intervention has been effective in improving personal health, social interactions, and other adaptive behaviors related to daily life skills [3]. The token economy is an intervention based on social learning and operant conditioning, which is governed by the two principles of the law of effect and contiguity so that reinforcers are systematically used to reinforce positive behavior or eliminate negative behavior, Reinforcers are used systematically to reinforce positive behavior or eliminate negative behavior, and tokens that are simple, accessible, and affordable are considered immediate reinforcers conditioned on the performance of the behavior, and later, they are exchanged with back-up reinforcers [4]. Just like the economy in the world, where people receive a generalized conditional reinforcer of money in exchange for performing their job duties, which they later use to buy various desirable reinforcers, and with this hope, they continue to perform their duties to make money again and spend it and this cycle goes on [5]. Contingency management, which is similarly based on operant conditioning, is an intervention that reinforces appropriate behavior with vouchers or prizes or punishes deviant behaviors. This intervention has the largest effect on substance abuse management compared to other psychosocial treatments [6]. Another intervention, behavioral activation, deposits that increasing a person’s activity and confronting him with the pleasant consequences of his action can increase positive behavior in that person [7]. 

In 2016, APA & Jansen. in a review article examined the impact of the token economy on the management of symptoms and behavior of people hospitalized in the psychiatric ward. They concluded that the token economy is effective in behavioral changes to reduce violence and aggression, but due to the lack of studies on the effect on negative symptoms, the effect of the token economy on negative symptoms cannot be generalized. There is a need for more studies not only on the impact of the token economy on behavior but also on the participation of people with mental illness [8].
 In this study, we tried to review the studies that investigated the impact of token economy intervention on people with chronic mental illness.

Materials and Methods

This study was conducted to review the studies related to token economy intervention in people with chronic mental illness.
Search strategy
 In this study, a search was made in PubMed and Google Scholar databases using the keywords “token economy” OR “token reinforcement” OR “contingency management”, AND “severe mental disorder” OR “serious mental illness” OR “chronic psychiatric disorder”, AND participation in the articles published from 2002 to 2022.
Inclusion criteria 
Controlled clinical trials, quasi-experimental studies with a pre-test and post-test design, pilot studies, and case reports that used behavioral reinforcement intervention in the form of token economy or approaches originating from token economy (contingency management and short-term behavioral activation) on people with severe mental illness were included to review.

Results

In the initial search, 92 articles were obtained. After reviewing and removing duplicates, 44 articles related to token economy in people with severe mental illness remained. However, 15 studies met the inclusion criteria and were selected for review (Figure 1).


Figure 1. Included studies

Table 1 summarized the study results.







Participants
 People with severe mental illness, schizophrenia, bipolar disorder, anxiety, and major depression, as well as people with substance abuse co-occurring with severe mental illness in the contexts of inpatient in hospital or residential settings, outpatient, home, and prison, were examined. The age range of participants was 17-81 years and most of them were in their late 40s and early 50s. The sample size of the articles ranged from 1 to 176, and the number of male participants was more than female counterparts (67%). 
Interventions
In the reviewed studies, first, the target behaviors that should be developed and maintained or removed were determined. Then, the type of token and backup reinforcer was determined, which is desirable for the client. 
The quality and quantity of the person’s performance, for which tokens are awarded, is stated. The program for producing and exchanging tokens was developed in a time-based or response-based manner, and the number of tokens required for exchange with the desired backup reinforcer was determined. Behavioral interventions in the form of token economy, contingency management, and short-term behavioral activation based on the principles of token economy, alone or combined with psychotherapy intervention, occupation-based intervention, psychoeducation, and individual counseling were implemented.
Outcomes
The examined results included self-care skills, such as bathing, dressing, eating, hygiene, grooming, toileting [9-12, 17], reducing alcohol use [6], drug abstinence, and smoking secession [13, 14, 19], symptoms of diseases, such as catatonia [15], negative symptoms of schizophrenia [18], depression [7], and violence and aggression [13, 20, 21].

Discussion

Token economy is a behavioral modification system based on operant conditioning, which modifies and shapes behavior using worthless tokens that can be exchanged for valuable reinforcers as an external motivator for clients who are unmotivated and should be hospitalized. This method can increase patients’ participation in treatment by increasing their motivation [22].
According to the mentioned studies, the impact of the token economy on the symptoms of diseases, occupation, drug and alcohol abstinence, smoking cessation, and violence has been investigated [7, 9-21] In the basic daily life activities, Token economy alone [11, 12, 17] or in combination with occupation-based interventions [9] and occupational therapy based on the MOHO model [10] showed significant changes in bathing, dressing, toileting, eating, and grooming of people with severe mental illness compared to other interventions implemented for the control groups.
Regarding mental illness symptoms, the short-term behavioral activation intervention showed a significant reduction with a high effect size compared to other interventions in the control group [7]. Gholipour et al. (2012) concluded that the token economy is more effective than exercise in reducing the negative symptoms of schizophrenic patients [18]. The combined interventions of token economy and activity-based occupational therapy reduced the symptoms of catatonia in a schizophrenic patient and occupational therapy based on the Moho model showed a reduction in the symptoms of depression and psychosis in chronic mental patients [10, 15]. McDonnell et al. (2013) suggested that contingency management along with abstinence from drugs, can reduce the psychological symptoms of addicts with co-occurring severe mental illness [16].
The results obtained in violence and aggression are contradictory. Park and Lee (2012) stated that the token economy caused a significant reduction in aggression in the form of verbal and physical attacks and property damage compared to the control group, which showed an increase in these behaviors [20]. In LePage et al.’s study (2003) on psychiatric patients hospitalized in the acute ward, harm to other patients and the severity of harm to staff decreased significantly, but no significant changes were found in self-harm behaviors and frequency of harm to staff [21]. Meyers et al. (2018) assessed chronically mentally ill prisoners and showed that minor violence, including failure to maintain grooming requirements, being out of place, littering, clowning, smoking, or the use of tobacco in an unauthorized area increased with contingency management intervention [13].
The contingency management intervention, which is implemented with the aim of drug abstinence, smoking, and alcohol use reduction for addicts with severe mental illness, caused more abstinence in the intervention group than the control group in alcohol usage, smoking, and psycho-stimulant drugs. The period of abstinence from alcohol and smoking was maintained longer in comparison to the control group [6, 13, 14, 16]. The only study by Adams et al. (2012) on the schizophrenic soldier with alcohol and cocaine abuse did not show this effect, which according to the authors’ statement, abstinence behavior was not their direct goal [19].
Using the token economy method can be a means to reduce the symptoms of mental illness and drug abstinence and improve performance in the basic daily living activities of people with chronic mental illness. This method increases the client’s life skills and independence by improving the motivation to participate in functional activities and causes reorientation of the lost sense of identity and self-efficacy due to the occurrence of the disease, which leads to improvement of the client’s quality of life. However, the correct implementation of this method is very important, and if the principles are not followed, it may be misused and undesired behaviors may be reinforced [19].
Considering that only five of the 15 reviewed studies were randomized clinical trials mostly on drug abstinence, it is recommended that higher quality research be done on basic activities of daily living, mental psychological symptoms, and violence management. Also, the ability to maintain the results obtained from the intervention and transfer them to society should be investigated. For violence management, the necessary changes in the protocol implementation should be considered to increase the motivation to make the token economy more effective. It is also recommended to conduct wider studies on the effect of this method in combination with other interventions on occupational performance and mental illness symptoms.

Conclusion

The review of studies in this research supports the effectiveness of the token economy in improving self-care activities, reducing disease symptoms, and smoking, alcohol, and drug abstinence in people with chronic mental illness. However, the effect of this method on the management of violence has not been achieved. This reward-based approach should be considered by practitioners who work with people with mental illness to improve adaptive behavior and performance in everyday life. During the implementation of the token economy method, the client-centered approach should be considered to recover from the client’s point of view [9]. because there have been few studies on the impact of the token economy on basic daily living activities, disease symptoms, and violence, the results indicated the need for higher-quality research on these factors and the occupational performance of people with chronic mental illness. 

Ethical Considerations
Compliance with ethical guidelines

There were no ethical considerations to be considered in this research.

Funding

This research did not receive any grant from funding agencies in the public, commercial, or non-profit sectors.

Authors' contributions

Conceptualization and supervision and methodology: Elahe Hojati Abed and Mitra Khalafbeigi; Investigation, writing-review & editing and writing original draft: Fatemenh Ghojoghi.

Conflict of interest

The authors declared no conflict of interest.

Acknowledgments

This research was completed in partial fulfillment of the third author`s Master`s Thesis in the occupational therapy by the third author from the Department of occupational therapy at Iran University of Medical Sciences. The author would like to give particular thanks to the personnel and clients of The OmidFarda Rehabilitation Center, where the research first started based on a clinical need.

References