The American Journal on Addictions, 23: 249–256, 2014 Copyright © American Academy of Addiction Psychiatry ISSN: 1055-0496 print / 1521-0391 online DOI: 10.1111/j.1521-0391.2014.12090.x
Prevalence of Psychiatric Disorders among Heroin Users Who Received Methadone Maintenance Therapy in Taiwan Chiung‐Yueh Fan, MD,1 Happy Kuy‐Lok Tan, MPH,1 I‐Chia Chien, PhD,1,2 Sun‐Yuan Chou, MD1 1 2
Department of Health, Taoyuan Mental Hospital, Taoyuan, Taiwan Department of Public Health and Institute of Public Health, National Yang‐Ming University, Taipei, Taiwan
Background: Many patients under methadone maintenance treatment are present with comorbid psychiatric symptoms. Objective: We wish to examine the prevalence of psychiatric disorders among heroin users who received methadone maintenance therapy (MMT) in Taiwan. Methods: By combining the National Health Insurance Research database and Center for Disease Control database, 18,271 heroin users who received MMT were defined as the subject group and after matching age and sex, 73,084 patients were randomly selected as the control group. Results: The 1 year prevalence of any psychiatric disorder, any psychotic disorder, neurotic and other nonpsychotic disorder among MMT patients and control group were 13.14% versus 2.50% (OR 5.89, CI 5.53–6.27), 4.21% versus 1.29% (OR 3.38, CI 3.07–3.72), and 9.89% versus 1.31% (OR 8.25, CI 7.62–8.94), respectively. Conclusion: The prevalence of any co‐morbid psychiatric disorder among MMT patients is almost six times higher than the control group. Scientific Significance: A thorough psychiatric screening and appropriate aggressive intervention should be incorporated into an effective methadone treatment program. (Am J Addict 2014;23:249– 256)
INTRODUCTION Coexisting psychiatric disorder among heroin users has been frequently mentioned in previous literature. Among the MMT patients, Callaly et al.1 found that lifetime prevalence of psychiatric disorder is up to 10 times higher than the general population, and even 2–3 times higher than those diagnosed with substance abuse history. These studies have consistently
Received January 7, 2013; revised May 6, 2013; accepted June 1, 2013. Address correspondence to Dr. Chou, Department of Health, Taoyuan Mental Hospital, No. 71, Longshou Street, Taoyuan City, Taoyuan County 330‐58, Taiwan. E‐mail: [email protected], [email protected].
shown that heroin users suffer high rates of nonsubstance use psychiatric disorder, with major depression the most prevalent current Axis I disorder (approximately 6–55%) and antisocial personality disorder (approximately 25–72%) the most common current Axis II disorder.1–7 The high prevalence of psychopathology among heroin users has direct implications for treatment outcome and clinical practice. Psychiatric co‐morbidity among heroin users has been found to have higher dependence on nonopiate drugs,2,5,8 a higher level of HIV risk‐taking behavior, increased suicide attempts,9–11 greater psychosocial problems,2 and lower quality of life.12–15 Therefore, incorporating a thorough psychiatric evaluation and treatment plan within the MMT is suggested.16–17 Major changes have occurred over the past years in Taiwan on the pathway of viewing heroin users from prisoners to patients. To use or to possess heroin is still illegal, however instead of incarceration in a residential detoxification or rehabilitation center administered by the Taiwan Ministry of Justice, deferred prosecution has recently become another option, which is to receive methadone maintenance therapy (MMT) for at least 1 year as an outpatient in the hospital. This option increases the opportunity for heroin users to get in contact with the mental health service. This is a remarkable improvement. It not only decreases the spread of HIV from a harm reduction point of view,18 but more importantly, from a public health perspective, health practitioners gain access to a group of patients who suffer up to 10 times more psychiatric disorders than the general population.16 MMT was introduced to Taiwan in 2005 and it expanded rapidly as a part of the harm‐reduction policy that was implemented due to the spread of HIV. By the end of 2008, 100 MMT clinics were set up in Taiwan to treat around 12,000 heroin users and the harm‐reduction programs successfully resulted in a decreased number of injecting drug users newly infected with HIV.18 Despite the evidence that patients on MMT have high psychiatric co‐morbidity, the emphasis of the MMT program in Taiwan was mostly on preventing the spread 249
of HIV. Limited efforts have been put into the patients’ mental health or addiction treatment, including a thorough psychiatry evaluation, detecting and treating psychiatric co‐morbidity, providing further psychosocial interventions and rehabilitation resources, and setting up individualized treatment plans to prevent further relapse. Despite widely published studies on the characteristics of MMT patients in western countries, there is limited information of such patients in Taiwan. Due to differences in government policies, health‐care delivery systems, and ethnic groups, we need more information about Taiwan’s MMT patients in order to improve our treatment. Chen et al.19 started the psychiatric co‐morbidity research in Taiwan among heroin patients and found that 83% of the hospital subjects and 66% of the incarcerated subjects had a least one coexisting DSM axis I or II disorder. Similar to western literature, additional substance use disorder, mood disorder, and antisocial personality disorder were the most prevalent diagnoses. Chiang et al.20 followed up 155 MMT patients and found that 43% of the males had antisocial personality disorder and 37.5% of the females had mood disorder. Wang et al. further pointed out predictors of the severity of depressive symptoms, such as female gender and concurrent methamphetamine use. Lee et al.21 reported in a sample of 576 patients that a substantial number of patients reported anxiety (21.0%), depression (27.2%), and memory loss (32.7%) and had been given psychotropic medication (16.1%). However, these data were limited to local hospitals and due to the limitation of face to face interviews, the sample size was relatively small. Further research should focus on the psychiatric symptoms and characteristics of the MMT patients on a national level to provide better relevant psychiatric treatment. Taiwan launched its National Health Insurance (NHI) program in March 1995, offering a comprehensive, unified, and universal health insurance program to all citizens. Since then, the National Health Insurance Research Database (NHIRD) has been an important source to further explore the prevalence, treatment, co‐morbidity rate, and costs of different diseases. The completeness and accuracy of the NHI claims databases have been audited by the Department of Health and the Bureau of NHI. Diagnostic codes in the database are in the format of the International Classification of Diseases, Revision 9, Clinical Modification (ICD‐9‐CM). Psychiatric diagnoses were made by board‐certified psychiatrists after interview in order to apply for health coverage by the NHI. The NHIRD has been used extensively in many epidemiological studies in Taiwan. Chien et al.22 published a series of studies on the prevalence and incidence of psychiatric illness in Taiwan using the NHI data, which reflect real world treatment practice. By combining the database of MMT and NHI, we wish to further explore the prevalence of psychiatric disorders among heroin users who received MMT in Taiwan. This would be the first study from a national perspective to reflect the prevalence of psychiatric disorders among heroin users who received MMT. 250
MATERIALS AND METHODS Overall Design This is a cross‐sectional study design. The CDC national database recorded all MMT enrollees since Taiwan adopted the MMT model. The NHIRD, which provides health care for over 99.5% of the residents in Taiwan, consists of ambulatory care and inpatient records as well as the registration files of the NHI enrollees. The CDC database was transferred by VPN and linked with NHI database. The ID numbers were encrypted before the analysis. The process of the linkage and analysis of the CDC and NHIR databases were performed directly by the NHI staff and handed to us afterwards. The Institutional Review Board of the Toayuan Mental Hospital approved the study. Subjects We included patients who were MMT enrollees and also enrolled in the NHI for over 6 months in the year 2008. A total of 18,271 patients were identified and demographic variables, including age, sex, insurance amount, and residential area were obtained. Control Group Among the enrollees in the NHIRD 2008, we excluded those who were identified as MMT users in 2008 and excluded those who participated in the NHI for less than 6 months. The ratio of subjects to controls is 1:4 and 73,084 controls were randomly selected. The randomization was carried out by a SAS program. We selected all samples from the NHI database with matched gender and age with each of our cases, and used the SAS function RANUNI with seed is 0. The process is repeated for every single case and the control group is formed. Definition of Psychiatric Disorder Data for subjects and controls who had at least one service claim in 2008 for either ambulatory or inpatient care, with the principle diagnosis of a psychiatric disorder, were categorized into one of the psychiatric disorder classifications according to International Classification of Diseases, 9th Revision, Clinical Modification (ICD‐9‐CM) diagnostic criteria. We divided psychiatric disorders into psychotic disorder and neurotic disorder and other nonpsychotic disorder. Psychotic disorder included ICD‐9‐CM codes senile and presnile organic psychotic conditions (290), alcoholic psychoses (291), drug psychoses (292), transient organic psychotic conditions (293), other organic psychotic conditions (294), schizophrenic disorders (295), affective psychoses (296), paranoid states (297), and other nonorganic psychosis (298). Neurotic disorder and other nonpsychotic disorder included neurotic disorder (300), personality disorder (301), sexual deviations and disorders (302), physiological malfunction arising from mental factors (306), special symptoms or syndromes not elsewhere classified (307), acute reaction to stress (308), adjustment reaction (309), specific nonpsychotic mental disorder due to organic brain damage (310), depressive disorder not elsewhere
Psychiatric Comorbidity among MMT Patients
May–June 2014
classified (311), and psychic factors associated with diseases classified elsewhere (316). The NHI does not reimburse patients for treatment when the diagnosis is solely substance use disorder (303–305) unless patients also suffer from other psychiatric comorbidity, withdrawal delirium (291.8x or 292.8x), or when the diagnosis meet the criteria of substance induced disorders (291.xx or 292.xx). Therefore, the prevalence of other substance use disorder (303–305) among MMT patients is unavailable from the NHI database. When claim data showed a person had two or more types of psychiatric disorder, we followed the algorithm previously mentioned by Chien et al.22 to decide which diagnosis should be considered the primary diagnosis to be used in the study. In summary, psychiatrists can help certain psychiatric patients who suffer from chronic and severe psychiatric illness to apply for catastrophic illness registration (CIR) card under the strict regulation of the Bureau of NHI. Using these cards, enrollees do not make copayments for receiving mental health care. For patients with two or more psychiatric disorders listed in the claim data, the diagnosis listed on the CIR card is used. For persons without CIR cards, we chose the diagnosis associated with inpatient treatment according to frequency. For persons without inpatient stays, we chose the diagnosis with outpatient care according to frequency. Statistical Analysis The differences between the demographic data of psychiatric prevalence among MMT patients and controls were analyzed using chi‐square tests. The significance level was set at .01.
RESULTS Table 1 shows the demographic data of MMT patients and control group. Over 80% of the patients receiving MMT in 2008 in Taiwan were male and over 70% were 25–44 years. Over half (59.8%) of the patients who received MMT were grouped in the fixed insurance premium, indicating the lowest socioeconomic status, while forty percent of the patients in the control group were grouped in the insurance amount U.S.$ 640–1,280, reaching a significant difference (p < .0001). Table 2 shows the comparison of current prevalence of psychiatric disorders between MMT patients and the control group. The MMT patients had significantly higher current prevalence of any psychiatric disorder, any psychotic disorder, and any neurotic and other nonpsychotic disorder 13.14% versus 2.50% (OR 5.89, CI 5.53–6.27), 4.21% versus 1.29% (OR 3.38, CI 3.07–3.72), and 9.89% versus 1.31% (OR 8.25, CI 7.62–8.94), respectively, when compared to the control group. The most significant difference between the MMT patients and the control group was the current prevalence of drug psychoses (292) .56% versus .01% (OR 58.61, CI 27.25– 126.07).
DISCUSSION Main Finding This study revealed MMT patients in Taiwan had high psychiatric co‐morbidities. The prevalence of any co‐morbid
TABLE 1. Demographic data of patients receiving MMT and matched control group
MMT patients
Control
Demographic characteristics
Number (%)
Number (%)
N Sex Male Female Age (years) 17 and younger 18–24 25–44 45–64 65 and older Insured amount (U.S.$) Fixed insurance premium Dependent Less than U.S.$ 640 U.S.$ 640–1,280 U.S.$ 1,281 and more Residential area Metropolitan Urban Rural
18,271
73,084
p‐value (chi‐square) 1.0000
15,272 (83.59) 2,999 (16.41)
61,088 (83.59) 11,996 (16.41) 1.0000
4 526 14,148 3,515 78
(.02) (2.88) (77.43) (19.23) (.43)
10,926 1,532 1,094 4,584 135
(59.80) (8.38) (5.99) (25.09) (.74)
16 2,104 56,592 14,060 312
Prevalence of Psychiatric Disorders among Heroin Users Who Received Methadone Maintenance Therapy in Taiwan Chiung‐Yueh Fan, MD,1 Happy Kuy‐Lok Tan, MPH,1 I‐Chia Chien, PhD,1,2 Sun‐Yuan Chou, MD1 1 2
Department of Health, Taoyuan Mental Hospital, Taoyuan, Taiwan Department of Public Health and Institute of Public Health, National Yang‐Ming University, Taipei, Taiwan
Background: Many patients under methadone maintenance treatment are present with comorbid psychiatric symptoms. Objective: We wish to examine the prevalence of psychiatric disorders among heroin users who received methadone maintenance therapy (MMT) in Taiwan. Methods: By combining the National Health Insurance Research database and Center for Disease Control database, 18,271 heroin users who received MMT were defined as the subject group and after matching age and sex, 73,084 patients were randomly selected as the control group. Results: The 1 year prevalence of any psychiatric disorder, any psychotic disorder, neurotic and other nonpsychotic disorder among MMT patients and control group were 13.14% versus 2.50% (OR 5.89, CI 5.53–6.27), 4.21% versus 1.29% (OR 3.38, CI 3.07–3.72), and 9.89% versus 1.31% (OR 8.25, CI 7.62–8.94), respectively. Conclusion: The prevalence of any co‐morbid psychiatric disorder among MMT patients is almost six times higher than the control group. Scientific Significance: A thorough psychiatric screening and appropriate aggressive intervention should be incorporated into an effective methadone treatment program. (Am J Addict 2014;23:249– 256)
INTRODUCTION Coexisting psychiatric disorder among heroin users has been frequently mentioned in previous literature. Among the MMT patients, Callaly et al.1 found that lifetime prevalence of psychiatric disorder is up to 10 times higher than the general population, and even 2–3 times higher than those diagnosed with substance abuse history. These studies have consistently
Received January 7, 2013; revised May 6, 2013; accepted June 1, 2013. Address correspondence to Dr. Chou, Department of Health, Taoyuan Mental Hospital, No. 71, Longshou Street, Taoyuan City, Taoyuan County 330‐58, Taiwan. E‐mail: [email protected], [email protected].
shown that heroin users suffer high rates of nonsubstance use psychiatric disorder, with major depression the most prevalent current Axis I disorder (approximately 6–55%) and antisocial personality disorder (approximately 25–72%) the most common current Axis II disorder.1–7 The high prevalence of psychopathology among heroin users has direct implications for treatment outcome and clinical practice. Psychiatric co‐morbidity among heroin users has been found to have higher dependence on nonopiate drugs,2,5,8 a higher level of HIV risk‐taking behavior, increased suicide attempts,9–11 greater psychosocial problems,2 and lower quality of life.12–15 Therefore, incorporating a thorough psychiatric evaluation and treatment plan within the MMT is suggested.16–17 Major changes have occurred over the past years in Taiwan on the pathway of viewing heroin users from prisoners to patients. To use or to possess heroin is still illegal, however instead of incarceration in a residential detoxification or rehabilitation center administered by the Taiwan Ministry of Justice, deferred prosecution has recently become another option, which is to receive methadone maintenance therapy (MMT) for at least 1 year as an outpatient in the hospital. This option increases the opportunity for heroin users to get in contact with the mental health service. This is a remarkable improvement. It not only decreases the spread of HIV from a harm reduction point of view,18 but more importantly, from a public health perspective, health practitioners gain access to a group of patients who suffer up to 10 times more psychiatric disorders than the general population.16 MMT was introduced to Taiwan in 2005 and it expanded rapidly as a part of the harm‐reduction policy that was implemented due to the spread of HIV. By the end of 2008, 100 MMT clinics were set up in Taiwan to treat around 12,000 heroin users and the harm‐reduction programs successfully resulted in a decreased number of injecting drug users newly infected with HIV.18 Despite the evidence that patients on MMT have high psychiatric co‐morbidity, the emphasis of the MMT program in Taiwan was mostly on preventing the spread 249
of HIV. Limited efforts have been put into the patients’ mental health or addiction treatment, including a thorough psychiatry evaluation, detecting and treating psychiatric co‐morbidity, providing further psychosocial interventions and rehabilitation resources, and setting up individualized treatment plans to prevent further relapse. Despite widely published studies on the characteristics of MMT patients in western countries, there is limited information of such patients in Taiwan. Due to differences in government policies, health‐care delivery systems, and ethnic groups, we need more information about Taiwan’s MMT patients in order to improve our treatment. Chen et al.19 started the psychiatric co‐morbidity research in Taiwan among heroin patients and found that 83% of the hospital subjects and 66% of the incarcerated subjects had a least one coexisting DSM axis I or II disorder. Similar to western literature, additional substance use disorder, mood disorder, and antisocial personality disorder were the most prevalent diagnoses. Chiang et al.20 followed up 155 MMT patients and found that 43% of the males had antisocial personality disorder and 37.5% of the females had mood disorder. Wang et al. further pointed out predictors of the severity of depressive symptoms, such as female gender and concurrent methamphetamine use. Lee et al.21 reported in a sample of 576 patients that a substantial number of patients reported anxiety (21.0%), depression (27.2%), and memory loss (32.7%) and had been given psychotropic medication (16.1%). However, these data were limited to local hospitals and due to the limitation of face to face interviews, the sample size was relatively small. Further research should focus on the psychiatric symptoms and characteristics of the MMT patients on a national level to provide better relevant psychiatric treatment. Taiwan launched its National Health Insurance (NHI) program in March 1995, offering a comprehensive, unified, and universal health insurance program to all citizens. Since then, the National Health Insurance Research Database (NHIRD) has been an important source to further explore the prevalence, treatment, co‐morbidity rate, and costs of different diseases. The completeness and accuracy of the NHI claims databases have been audited by the Department of Health and the Bureau of NHI. Diagnostic codes in the database are in the format of the International Classification of Diseases, Revision 9, Clinical Modification (ICD‐9‐CM). Psychiatric diagnoses were made by board‐certified psychiatrists after interview in order to apply for health coverage by the NHI. The NHIRD has been used extensively in many epidemiological studies in Taiwan. Chien et al.22 published a series of studies on the prevalence and incidence of psychiatric illness in Taiwan using the NHI data, which reflect real world treatment practice. By combining the database of MMT and NHI, we wish to further explore the prevalence of psychiatric disorders among heroin users who received MMT in Taiwan. This would be the first study from a national perspective to reflect the prevalence of psychiatric disorders among heroin users who received MMT. 250
MATERIALS AND METHODS Overall Design This is a cross‐sectional study design. The CDC national database recorded all MMT enrollees since Taiwan adopted the MMT model. The NHIRD, which provides health care for over 99.5% of the residents in Taiwan, consists of ambulatory care and inpatient records as well as the registration files of the NHI enrollees. The CDC database was transferred by VPN and linked with NHI database. The ID numbers were encrypted before the analysis. The process of the linkage and analysis of the CDC and NHIR databases were performed directly by the NHI staff and handed to us afterwards. The Institutional Review Board of the Toayuan Mental Hospital approved the study. Subjects We included patients who were MMT enrollees and also enrolled in the NHI for over 6 months in the year 2008. A total of 18,271 patients were identified and demographic variables, including age, sex, insurance amount, and residential area were obtained. Control Group Among the enrollees in the NHIRD 2008, we excluded those who were identified as MMT users in 2008 and excluded those who participated in the NHI for less than 6 months. The ratio of subjects to controls is 1:4 and 73,084 controls were randomly selected. The randomization was carried out by a SAS program. We selected all samples from the NHI database with matched gender and age with each of our cases, and used the SAS function RANUNI with seed is 0. The process is repeated for every single case and the control group is formed. Definition of Psychiatric Disorder Data for subjects and controls who had at least one service claim in 2008 for either ambulatory or inpatient care, with the principle diagnosis of a psychiatric disorder, were categorized into one of the psychiatric disorder classifications according to International Classification of Diseases, 9th Revision, Clinical Modification (ICD‐9‐CM) diagnostic criteria. We divided psychiatric disorders into psychotic disorder and neurotic disorder and other nonpsychotic disorder. Psychotic disorder included ICD‐9‐CM codes senile and presnile organic psychotic conditions (290), alcoholic psychoses (291), drug psychoses (292), transient organic psychotic conditions (293), other organic psychotic conditions (294), schizophrenic disorders (295), affective psychoses (296), paranoid states (297), and other nonorganic psychosis (298). Neurotic disorder and other nonpsychotic disorder included neurotic disorder (300), personality disorder (301), sexual deviations and disorders (302), physiological malfunction arising from mental factors (306), special symptoms or syndromes not elsewhere classified (307), acute reaction to stress (308), adjustment reaction (309), specific nonpsychotic mental disorder due to organic brain damage (310), depressive disorder not elsewhere
Psychiatric Comorbidity among MMT Patients
May–June 2014
classified (311), and psychic factors associated with diseases classified elsewhere (316). The NHI does not reimburse patients for treatment when the diagnosis is solely substance use disorder (303–305) unless patients also suffer from other psychiatric comorbidity, withdrawal delirium (291.8x or 292.8x), or when the diagnosis meet the criteria of substance induced disorders (291.xx or 292.xx). Therefore, the prevalence of other substance use disorder (303–305) among MMT patients is unavailable from the NHI database. When claim data showed a person had two or more types of psychiatric disorder, we followed the algorithm previously mentioned by Chien et al.22 to decide which diagnosis should be considered the primary diagnosis to be used in the study. In summary, psychiatrists can help certain psychiatric patients who suffer from chronic and severe psychiatric illness to apply for catastrophic illness registration (CIR) card under the strict regulation of the Bureau of NHI. Using these cards, enrollees do not make copayments for receiving mental health care. For patients with two or more psychiatric disorders listed in the claim data, the diagnosis listed on the CIR card is used. For persons without CIR cards, we chose the diagnosis associated with inpatient treatment according to frequency. For persons without inpatient stays, we chose the diagnosis with outpatient care according to frequency. Statistical Analysis The differences between the demographic data of psychiatric prevalence among MMT patients and controls were analyzed using chi‐square tests. The significance level was set at .01.
RESULTS Table 1 shows the demographic data of MMT patients and control group. Over 80% of the patients receiving MMT in 2008 in Taiwan were male and over 70% were 25–44 years. Over half (59.8%) of the patients who received MMT were grouped in the fixed insurance premium, indicating the lowest socioeconomic status, while forty percent of the patients in the control group were grouped in the insurance amount U.S.$ 640–1,280, reaching a significant difference (p < .0001). Table 2 shows the comparison of current prevalence of psychiatric disorders between MMT patients and the control group. The MMT patients had significantly higher current prevalence of any psychiatric disorder, any psychotic disorder, and any neurotic and other nonpsychotic disorder 13.14% versus 2.50% (OR 5.89, CI 5.53–6.27), 4.21% versus 1.29% (OR 3.38, CI 3.07–3.72), and 9.89% versus 1.31% (OR 8.25, CI 7.62–8.94), respectively, when compared to the control group. The most significant difference between the MMT patients and the control group was the current prevalence of drug psychoses (292) .56% versus .01% (OR 58.61, CI 27.25– 126.07).
DISCUSSION Main Finding This study revealed MMT patients in Taiwan had high psychiatric co‐morbidities. The prevalence of any co‐morbid
TABLE 1. Demographic data of patients receiving MMT and matched control group
MMT patients
Control
Demographic characteristics
Number (%)
Number (%)
N Sex Male Female Age (years) 17 and younger 18–24 25–44 45–64 65 and older Insured amount (U.S.$) Fixed insurance premium Dependent Less than U.S.$ 640 U.S.$ 640–1,280 U.S.$ 1,281 and more Residential area Metropolitan Urban Rural
18,271
73,084
p‐value (chi‐square) 1.0000
15,272 (83.59) 2,999 (16.41)
61,088 (83.59) 11,996 (16.41) 1.0000
4 526 14,148 3,515 78
(.02) (2.88) (77.43) (19.23) (.43)
10,926 1,532 1,094 4,584 135
(59.80) (8.38) (5.99) (25.09) (.74)
16 2,104 56,592 14,060 312
