G Model
AJP-671; No. of Pages 10 Asian Journal of Psychiatry xxx (2015) xxx–xxx
Contents lists available at ScienceDirect
Asian Journal of Psychiatry journal homepage: www.elsevier.com/locate/ajp
Review
Course and Outcome of Schizophrenia in Asian Countries: Review of Research in the Past Three Decades Bharath Holla, Jagadisha Thirthalli * Department of Psychiatry, National Institute of Mental Health & Neurosciences (NIMHANS), Bangalore
A R T I C L E I N F O
A B S T R A C T
Article history: Received 7 October 2014 Received in revised form 5 January 2015 Accepted 18 January 2015 Available online xxx
Considerable variation has been observed in the course and outcome of schizophrenia. With regard to epidemiology of schizophrenia, papers from different Asian countries have reported findings which are in contrast with literature from the western countries. In this background we undertook a narrative review of literature regarding course and outcome of schizophrenia in Asian countries. We conducted Medline search for English-language papers on long-term course and outcome of schizophrenia conducted in Asia in the past 3 decades. We also reviewed data pertaining to Asian countries from the World Health Organization’s International Study of Schizophrenia (ISoS). In addition to ISoS, we retrieved 14 reports from 9 Asian countries. While ISoS used comparable methodology across the countries, non-ISoS studies differed substantially in their aims, sampling, follow-up rates and assessment tools used for studying the course and outcome. Overall, the percentage of patients who experienced clinical and functional outcome in the Asian countries were largely comparable to those in the western studies. We observed significant variations in the long-term outcome and mortality in schizophrenia even among the Asian countries. In conclusion, there is substantial variation in the longterm course and outcome and mortality across different Asian countries. The reason for this remains unexplored. Cross-national studies exploring biological and cultural explanations for this variation may provide clues, which may have heuristic, translational and public-health significance. ß 2015 Elsevier B.V. All rights reserved.
Keywords: Schizophrenia Asia Course Outcome Mortality
Contents 1. 2. 3.
4.
5.
Background . . . . . . . . . . . . . . . . . . . . . . . . Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . ISoS centres (Tables 1 and 2) . . . . . 3.1. Non-ISoS studies (Tables 3 and 4) . 3.2. Mortality . . . . . . . . . . . . . . . . . . . . . 3.3. Substance use comorbidity. . . . . . . 3.4. Predictors of outcome. . . . . . . . . . . 3.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . Mortality . . . . . . . . . . . . . . . . . . . . . 4.1. Substance use comorbidity. . . . . . . 4.2. Antipsychotic treatment . . . . . . . . . 4.3. Limitations . . . . . . . . . . . . . . . . . . . 4.4. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000
* Corresponding author. Additional Professor, Department of Psychiatry, National Institute of Mental Health & Neurosciences (NIMHANS), Bangalore, India. Tel.: +918026995350; fax: +918026564830. E-mail address: [email protected] (J. Thirthalli). http://dx.doi.org/10.1016/j.ajp.2015.01.001 1876-2018/ß 2015 Elsevier B.V. All rights reserved.
Please cite this article in press as: Holla, B., Thirthalli, J., Course and Outcome of Schizophrenia in Asian Countries: Review of Research in the Past Three Decades. Asian J. Psychiatry (2015), http://dx.doi.org/10.1016/j.ajp.2015.01.001
G Model
AJP-671; No. of Pages 10 2
B. Holla, J. Thirthalli / Asian Journal of Psychiatry xxx (2015) xxx–xxx
1. Background Kraepelin described dementia precox as a disorder characterized by a chronic, progressive course with minimal chances of clinical improvement (Kraepelin, 1899). Since then, course and outcome of this disorder, which later came to be popularly known as schizophrenia, has drawn considerable research interest. In fact, in an influential systematic review and meta-analysis conducted 2 decades ago (Hegarty et al., 1994), the authors identified 320 studies that met their fairly stringent inclusion criteria. This and other reviews (McGlashan, 1988; Stephens, 1978) have indicated that the outcome of schizophrenia is not uniformly poor; it is rather highly heterogeneous, and, on an average, substantially high proportion of persons who receive a diagnosis of schizophrenia experience reasonably good clinical and functional outcome. The heterogeneity stems from several sources: nature of sampling, criteria used to diagnose schizophrenia, use of modern treatment, particularly antipsychotic medications, provision of psychiatric services, etc. In the World Health Organization (WHO) follow up studies – International Pilot Study of Schizophrenia (IPSS) (WHO, 1979), Determinants of Outcome of Severe Mental Disorder (DOSMeD) (Jablensky et al., 1992) and International Study of Schizophrenia (ISoS) (Harrison et al., 2001) – another important factor influencing the course and outcome was noticed–patients belonging to the ‘developing’ countries had more favorable overall outcome than those in the ‘developed’ countries. The reason for this differential outcome has not been studied well. What is it in the developing countries that could favourably influence the course and outcome? A number of hypotheses have been put forth, but these have remain untested. Differences in the level of industrialization, urbanization, social support, family structure, expressed emotions, explanatory model for causation of the illness, societal challenges, etc., have been proposed to explain the differential outcome. Though countries were divided as ‘developed’ and ‘developing’ on economic status, it is not clear as to whether the economic status per se could be responsible for the differential outcomes. The differences observed may be better described as ‘regional’ differences, which encompass differences due to racial (genetic) environmental and sociocultural differences. Indeed, even within the ‘developed’ and ‘developing’ countries included in the WHO studies, substantial differences have been noted (Cohen et al., 2008). Studies from several Asian countries have documented many findings, which are in contrast to that of the rest of the world. For instance, prevalence of schizophrenia has been reported to be more in women than in men in Chinese studies (Cooper et al., 1996). Studies from India (Gangadhar et al., 2002; Murthy et al., 1998; Venkatesh et al., 2008) and Pakistan (Naqvi et al., 2005) have failed to find earlier age of onset of schizophrenia that is so well replicated elsewhere (Hafner et al., 1993). Substance use comorbidity, which can adversely influence the course and outcome of schizophrenia (Volkow, 2009), is found to be lower in India (Chand et al., 2014; Isaac et al., 2007); this reflects a fairly low occurrence of substance use and psychiatric disorders in many Asian countries (Thirthalli et al., 2012). Similarly, family expressed emotions, which also can adversely influence the course of schizophrenia is found to be lower in Indian families than in some of the western countries (Leff et al., 1990). There is an argument that repeated exposure to severe famines have possibly eliminated severest forms of schizophrenia and there is a natural selection in the favour of milder forms of schizophrenia in some Asian countries (Thirthalli and Jain, 2009). A recent study has also found that the proportion of patients who had longer than 6 months of prodrome was less than 10% (Kare et al., 2009) in contrast to the typical course of prodrome described in text books
(Sadock, 2000). With several studies showing that different dimensions of schizophrenia are different in the Asian countries, it is of interest to see if course and outcome of schizophrenia is different in these countries. 2. Methods In this narrative review, we attempt to provide an overview of the past three decades of research studies on course and outcome of schizophrenia in Asian countries. We conducted Medline search using the following combinations of keywords: ‘schizophrenia’, ‘psychosis’, ‘outcome’, ‘course’, ‘follow-up’, ‘Asia’ along with names of individual Asian countries. We further conducted author searches and used cross-references from the identified research reports. Papers published in English language, presenting results of research conducted in an Asian country since 1980 were reviewed if the follow-up period was at least 2 years. We reviewed only such follow-up studies, where either clinical/functional outcomes and/or mortality were reported (i.e., we did not review papers where other outcomes like stigma, quality of life, medication adherence, etc., were studied) In addition, we also reviewed data of Asian centres from the World Health Organization’s (WHO) influential ISoS project. The ISoS is a transcultural investigation coordinated by the WHO in 18 centres in 14 countries. It included cohorts from three earlier WHO studies, the IPSS (WHO, 1979), DOSMeD (Jablensky et al., 1992), Reduction and Assessment of Psychiatric Disability (RAPyD) (Wiersma et al., 1996) and three other centres not involved in these three studies. For this review, if more than one paper was published from a cohort, then we considered the data from the longest follow-up period; we also reviewed significant results from other related papers from those studies. We reviewed each study specifically with regard to the following characteristics: primary aim of the study, method of sampling, number of subjects included in the original cohort, percentage of subjects whose data was considered for outcome analysis, system and method of diagnosis, tools used for assessing clinical, functional, course-related and overall outcomes and mortality. Predictors of outcome were also reviewed. We specifically reviewed the papers for data on substance use comorbidity because of the following reasons: (a) it is known to adversely affect the outcome of schizophrenia (Volkow, 2009); (b) earlier long-term studies of schizophrenia have not specifically examined its influence on the course and outcome of schizophrenia and (c) substance use comorbidity is relatively lower in the Asian countries (Chand et al., 2014). Finally, we carefully examined the treatment details, which could influence the course and outcome of schizophrenia. 3. Results In addition to ISoS, we retrieved 14 studies which met our inclusion criteria. ISoS employed uniform method of assessing the course and outcome of the included cohorts, though the individual cohorts themselves were formed using substantially different methods. Hence, it would be useful to consider the results of all ISoS cohorts and non-ISoS cohorts separately. The results of the ISoS and non-ISoS studies are shown in Tables 1 and 2 and Tables 3 and 4 respectively. 3.1. ISoS centres (Tables 1 and 2) There were seven Asian sites in the ISoS, including four from India. The samples included community-dwelling patients, inpatients and outpatients with recent onset schizophrenia. The duration of follow-up ranged from 12 years to 26 years – centres from the DOSMeD study had 15 years of follow-up. There were wide variations in the percentage of the original cohort that was
Please cite this article in press as: Holla, B., Thirthalli, J., Course and Outcome of Schizophrenia in Asian Countries: Review of Research in the Past Three Decades. Asian J. Psychiatry (2015), http://dx.doi.org/10.1016/j.ajp.2015.01.001
G Model
AJP-671; No. of Pages 10 B. Holla, J. Thirthalli / Asian Journal of Psychiatry xxx (2015) xxx–xxx
3
Table 1 Details of cohorts in the International Study of Schizophrenia (ISoS; see text for details). Location Prevalence cohortsa Agra, India Beijing, China
Sampling details
Original cohort (n)
% followed-up
Duration of follow up (yr)
Males: Females (%)
Outpatients of mental hospital; 15-45 ears of age,
AJP-671; No. of Pages 10 Asian Journal of Psychiatry xxx (2015) xxx–xxx
Contents lists available at ScienceDirect
Asian Journal of Psychiatry journal homepage: www.elsevier.com/locate/ajp
Review
Course and Outcome of Schizophrenia in Asian Countries: Review of Research in the Past Three Decades Bharath Holla, Jagadisha Thirthalli * Department of Psychiatry, National Institute of Mental Health & Neurosciences (NIMHANS), Bangalore
A R T I C L E I N F O
A B S T R A C T
Article history: Received 7 October 2014 Received in revised form 5 January 2015 Accepted 18 January 2015 Available online xxx
Considerable variation has been observed in the course and outcome of schizophrenia. With regard to epidemiology of schizophrenia, papers from different Asian countries have reported findings which are in contrast with literature from the western countries. In this background we undertook a narrative review of literature regarding course and outcome of schizophrenia in Asian countries. We conducted Medline search for English-language papers on long-term course and outcome of schizophrenia conducted in Asia in the past 3 decades. We also reviewed data pertaining to Asian countries from the World Health Organization’s International Study of Schizophrenia (ISoS). In addition to ISoS, we retrieved 14 reports from 9 Asian countries. While ISoS used comparable methodology across the countries, non-ISoS studies differed substantially in their aims, sampling, follow-up rates and assessment tools used for studying the course and outcome. Overall, the percentage of patients who experienced clinical and functional outcome in the Asian countries were largely comparable to those in the western studies. We observed significant variations in the long-term outcome and mortality in schizophrenia even among the Asian countries. In conclusion, there is substantial variation in the longterm course and outcome and mortality across different Asian countries. The reason for this remains unexplored. Cross-national studies exploring biological and cultural explanations for this variation may provide clues, which may have heuristic, translational and public-health significance. ß 2015 Elsevier B.V. All rights reserved.
Keywords: Schizophrenia Asia Course Outcome Mortality
Contents 1. 2. 3.
4.
5.
Background . . . . . . . . . . . . . . . . . . . . . . . . Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . ISoS centres (Tables 1 and 2) . . . . . 3.1. Non-ISoS studies (Tables 3 and 4) . 3.2. Mortality . . . . . . . . . . . . . . . . . . . . . 3.3. Substance use comorbidity. . . . . . . 3.4. Predictors of outcome. . . . . . . . . . . 3.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . Mortality . . . . . . . . . . . . . . . . . . . . . 4.1. Substance use comorbidity. . . . . . . 4.2. Antipsychotic treatment . . . . . . . . . 4.3. Limitations . . . . . . . . . . . . . . . . . . . 4.4. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000
* Corresponding author. Additional Professor, Department of Psychiatry, National Institute of Mental Health & Neurosciences (NIMHANS), Bangalore, India. Tel.: +918026995350; fax: +918026564830. E-mail address: [email protected] (J. Thirthalli). http://dx.doi.org/10.1016/j.ajp.2015.01.001 1876-2018/ß 2015 Elsevier B.V. All rights reserved.
Please cite this article in press as: Holla, B., Thirthalli, J., Course and Outcome of Schizophrenia in Asian Countries: Review of Research in the Past Three Decades. Asian J. Psychiatry (2015), http://dx.doi.org/10.1016/j.ajp.2015.01.001
G Model
AJP-671; No. of Pages 10 2
B. Holla, J. Thirthalli / Asian Journal of Psychiatry xxx (2015) xxx–xxx
1. Background Kraepelin described dementia precox as a disorder characterized by a chronic, progressive course with minimal chances of clinical improvement (Kraepelin, 1899). Since then, course and outcome of this disorder, which later came to be popularly known as schizophrenia, has drawn considerable research interest. In fact, in an influential systematic review and meta-analysis conducted 2 decades ago (Hegarty et al., 1994), the authors identified 320 studies that met their fairly stringent inclusion criteria. This and other reviews (McGlashan, 1988; Stephens, 1978) have indicated that the outcome of schizophrenia is not uniformly poor; it is rather highly heterogeneous, and, on an average, substantially high proportion of persons who receive a diagnosis of schizophrenia experience reasonably good clinical and functional outcome. The heterogeneity stems from several sources: nature of sampling, criteria used to diagnose schizophrenia, use of modern treatment, particularly antipsychotic medications, provision of psychiatric services, etc. In the World Health Organization (WHO) follow up studies – International Pilot Study of Schizophrenia (IPSS) (WHO, 1979), Determinants of Outcome of Severe Mental Disorder (DOSMeD) (Jablensky et al., 1992) and International Study of Schizophrenia (ISoS) (Harrison et al., 2001) – another important factor influencing the course and outcome was noticed–patients belonging to the ‘developing’ countries had more favorable overall outcome than those in the ‘developed’ countries. The reason for this differential outcome has not been studied well. What is it in the developing countries that could favourably influence the course and outcome? A number of hypotheses have been put forth, but these have remain untested. Differences in the level of industrialization, urbanization, social support, family structure, expressed emotions, explanatory model for causation of the illness, societal challenges, etc., have been proposed to explain the differential outcome. Though countries were divided as ‘developed’ and ‘developing’ on economic status, it is not clear as to whether the economic status per se could be responsible for the differential outcomes. The differences observed may be better described as ‘regional’ differences, which encompass differences due to racial (genetic) environmental and sociocultural differences. Indeed, even within the ‘developed’ and ‘developing’ countries included in the WHO studies, substantial differences have been noted (Cohen et al., 2008). Studies from several Asian countries have documented many findings, which are in contrast to that of the rest of the world. For instance, prevalence of schizophrenia has been reported to be more in women than in men in Chinese studies (Cooper et al., 1996). Studies from India (Gangadhar et al., 2002; Murthy et al., 1998; Venkatesh et al., 2008) and Pakistan (Naqvi et al., 2005) have failed to find earlier age of onset of schizophrenia that is so well replicated elsewhere (Hafner et al., 1993). Substance use comorbidity, which can adversely influence the course and outcome of schizophrenia (Volkow, 2009), is found to be lower in India (Chand et al., 2014; Isaac et al., 2007); this reflects a fairly low occurrence of substance use and psychiatric disorders in many Asian countries (Thirthalli et al., 2012). Similarly, family expressed emotions, which also can adversely influence the course of schizophrenia is found to be lower in Indian families than in some of the western countries (Leff et al., 1990). There is an argument that repeated exposure to severe famines have possibly eliminated severest forms of schizophrenia and there is a natural selection in the favour of milder forms of schizophrenia in some Asian countries (Thirthalli and Jain, 2009). A recent study has also found that the proportion of patients who had longer than 6 months of prodrome was less than 10% (Kare et al., 2009) in contrast to the typical course of prodrome described in text books
(Sadock, 2000). With several studies showing that different dimensions of schizophrenia are different in the Asian countries, it is of interest to see if course and outcome of schizophrenia is different in these countries. 2. Methods In this narrative review, we attempt to provide an overview of the past three decades of research studies on course and outcome of schizophrenia in Asian countries. We conducted Medline search using the following combinations of keywords: ‘schizophrenia’, ‘psychosis’, ‘outcome’, ‘course’, ‘follow-up’, ‘Asia’ along with names of individual Asian countries. We further conducted author searches and used cross-references from the identified research reports. Papers published in English language, presenting results of research conducted in an Asian country since 1980 were reviewed if the follow-up period was at least 2 years. We reviewed only such follow-up studies, where either clinical/functional outcomes and/or mortality were reported (i.e., we did not review papers where other outcomes like stigma, quality of life, medication adherence, etc., were studied) In addition, we also reviewed data of Asian centres from the World Health Organization’s (WHO) influential ISoS project. The ISoS is a transcultural investigation coordinated by the WHO in 18 centres in 14 countries. It included cohorts from three earlier WHO studies, the IPSS (WHO, 1979), DOSMeD (Jablensky et al., 1992), Reduction and Assessment of Psychiatric Disability (RAPyD) (Wiersma et al., 1996) and three other centres not involved in these three studies. For this review, if more than one paper was published from a cohort, then we considered the data from the longest follow-up period; we also reviewed significant results from other related papers from those studies. We reviewed each study specifically with regard to the following characteristics: primary aim of the study, method of sampling, number of subjects included in the original cohort, percentage of subjects whose data was considered for outcome analysis, system and method of diagnosis, tools used for assessing clinical, functional, course-related and overall outcomes and mortality. Predictors of outcome were also reviewed. We specifically reviewed the papers for data on substance use comorbidity because of the following reasons: (a) it is known to adversely affect the outcome of schizophrenia (Volkow, 2009); (b) earlier long-term studies of schizophrenia have not specifically examined its influence on the course and outcome of schizophrenia and (c) substance use comorbidity is relatively lower in the Asian countries (Chand et al., 2014). Finally, we carefully examined the treatment details, which could influence the course and outcome of schizophrenia. 3. Results In addition to ISoS, we retrieved 14 studies which met our inclusion criteria. ISoS employed uniform method of assessing the course and outcome of the included cohorts, though the individual cohorts themselves were formed using substantially different methods. Hence, it would be useful to consider the results of all ISoS cohorts and non-ISoS cohorts separately. The results of the ISoS and non-ISoS studies are shown in Tables 1 and 2 and Tables 3 and 4 respectively. 3.1. ISoS centres (Tables 1 and 2) There were seven Asian sites in the ISoS, including four from India. The samples included community-dwelling patients, inpatients and outpatients with recent onset schizophrenia. The duration of follow-up ranged from 12 years to 26 years – centres from the DOSMeD study had 15 years of follow-up. There were wide variations in the percentage of the original cohort that was
Please cite this article in press as: Holla, B., Thirthalli, J., Course and Outcome of Schizophrenia in Asian Countries: Review of Research in the Past Three Decades. Asian J. Psychiatry (2015), http://dx.doi.org/10.1016/j.ajp.2015.01.001
G Model
AJP-671; No. of Pages 10 B. Holla, J. Thirthalli / Asian Journal of Psychiatry xxx (2015) xxx–xxx
3
Table 1 Details of cohorts in the International Study of Schizophrenia (ISoS; see text for details). Location Prevalence cohortsa Agra, India Beijing, China
Sampling details
Original cohort (n)
% followed-up
Duration of follow up (yr)
Males: Females (%)
Outpatients of mental hospital; 15-45 ears of age,
