Meta-analysis of stigma and mental health

Abstract

Recent research has emphasized the adverse effects of stigma on minority groups’ mental health. Governments and service agencies have put much effort into combating stigma against a variety of conditions. Nevertheless, previous empirical research on the stigma–mental health relationship has yielded inconclusive findings, varying from strong negative to zero correlations. Thus, whether stigma is related significantly to mental health is yet to be confirmed. Using meta-analysis, the associations between stigma and mental health from 49 empirical studies were examined across various stigmatized conditions and mental health indices. Possible moderators were also explored. The mean correlation between stigma and average mental health scores corrected for sampling error, unreliability, and other artifacts was −.28 (N=10,567, k=52). No strong moderators were found, yet meaningful patterns were observed. Implications of the results are discussed.

Introduction

Social stigma has been identified and recognized as a major concern in health care and human services across societies worldwide. It was first defined as a spoiled identity that discredits a person in society (Goffman, 1963). Individuals being relegated to this stigmatized status are believed “to possess some attribute that conveys a social identity that is devalued in a particular social context” (Crocker, Major, & Steele, 1998, p. 505). From the general public's view, stigma represents the endorsement of a set of prejudicial attitudes, negative emotional responses, discriminatory behaviors, and biased social structures towards members of a subgroup (Corrigan, 2000). It involves labeling, stereotyping, separation, status loss, and discrimination of the stigmatized individuals in a power situation (Link & Phelan, 2001).

Stigma can also be perceived by minority members and their associates. Termed as self-stigma, it is the internalization of the stigma responses from the general public by the target individuals. It occurs when members of a subgroup internalize the prejudicial attitudes and apply these attitudes toward themselves, leading to negative emotional responses and behaviors (Corrigan & Watson, 2002). Similar internalization of stigma can occur among the associates. Affiliate stigma is the psychological responses and identification of individuals who are closely associated with the target individuals (e.g., caregivers, family, and friends). Through association, these affiliates may internalize the stigma attached to the target, affecting their own well-being. It should be noted that although we have made a fine distinction among different concepts of stigma, the term stigma is used indiscriminately in the literature. For the purpose of this study, stigma is operationalized as internalized stigma construed by the minority members (a.k.a. self-stigma) and their associates (a.k.a. affiliate stigma) across different stigmatized conditions. In this meta-analysis we examine the relations between stigma and various positive and negative indicators of mental health.

Although the concept of stigma has been around for decades, only in the past decade has it gained increasing attention in research and in policy-making. A PsycINFO and PubMed search with the keyword stigma found more than 4278 related articles, with more than half of the articles being published between the years 2000 and 2005. This indicates a growing interest in the concept of stigma and its influence on psychological and medical research. Research on stigma encompassed a wide range of conditions, including mental illness, intellectual disability, HIV/AIDS, ethnicity, and sexual orientation, to name only a few.

In the Surgeon General's Report on Mental Health (US Department of Health and Human Services, 1999), strong emphasis was put on understanding the roots of stigma, its effects on mental health, and ways to overcome stigma. Following the issuance of this landmark report, in 2001, the National Institute of Mental Health (NIH) organized a major international conference, “Stigma and Global Health: Developing a Research Agenda,” to arouse attention and research efforts in examining the causes and consequences of stigma. Following the NIH's organizational restructuring in 2002, a new Stigma and Health Disparities Program under the Health and Behavior Research Branch in the Division of AIDS and Health and Behavior Research was formally established. The program focused on the issues of stigma; such as supporting research to understand its mechanisms, developing strategies to reduce stigma and examining media influences on mental illness perception. In 2003, about US$2.5 million was committed to the program supporting up to 12 new competitive grants. From the advancements in public policies, it could be shown that the influence of stigma on mental health has been widely recognized and regarded as important in the government policy-making process.

In addition to the growing research showing the potential impact of stigma on a variety of health conditions, health agencies have begun taking initiatives to combat stigma. The World Health Report (WHO, 2001) discussed possible ways to reduce stigma, including organizing anti-stigma activities and campaigns through partnerships with non-government organizations. The International HIV/AIDS Alliance identified stigma as a barrier to HIV/AIDS prevention and began stigma reduction programs in some developing countries. The Global Health Council also conducted research and provides resources to AIDS stigma prevention programs across the world. Various virtual campaigns against stigma of mental illness were also developed. These campaigns attempted to use the Internet and media to overcome stigma and monitor acts of discrimination at both the local and the global level.

It is evident from these efforts that stigma has been generally recognized as a global concern that must be addressed and overcome at multiple levels (e.g., individual, institutional systems, community, and regional). Governments, agencies, organizations, and research put resources into combating stigma. However, the empirical research evidence shows an inconsistent relation between stigma and mental health, ranging from non-significance to strong correlations. Some researchers argued that stigma does not necessary affect mental health (Corrigan & Kleinlein, 2005; Crocker & Major, 1989). Moreover, research suggests that stigma varies in degree, depending on the specific diagnosis and sociocultural group to which the target group belongs (e.g., Lau & Cheung, 1999; Lee, Lee, Chiu, & Kleinman, 2005). Therefore, before concluding that stigma and its effect on mental health are as important as we have been ardently suggesting, we need to empirically integrate and consolidate these findings to examine their association and to seek out possible moderators that could help us understand the relationship.

One means of aggregating research findings is through meta-analysis, a statistical analysis of previous studies quantitatively to integrate findings (Glass, 1976). It helps researchers to integrate and interpret primary research findings, which may diverge both in strength and direction, and make a more stringent conclusion about the subject of interest. Meta-analysis outweighs traditional narrative review methods in several ways. First, it is based on shared subjectivity of primary research rather than the reviewer's own stance. Second, statistical artifacts affecting the reported results of primary research can be corrected before aggregating and making judgments. Moreover, moderators can be examined through statistical methods in meta-analysis.

The purpose of our study is to synthesize previous findings on stigma and mental health in understanding the overall association between these two constructs. In addition to examining the integrated effects between stigma and mental health, we conducted a quality assessment of the studies. According to Khan, ter Riet, Popay, Nixon, and Kleijnen (2001) and Moher, Cook, Eastwood, Olkin, Rennie, and Stroup (1999), assessment of study quality is an important aspect in synthesized reviews and its rigor is an indication of the quality of the meta-analysis itself. Based on Wortman (1994), the present study assessed study quality along four dimensions: theory, publication bias, design, and sources of heterogeneity. Theory evaluates construct validity, or whether the study focuses on testing the relationship between stigma and mental health and whether an operational definition is provided for the theoretical constructs. Publication bias assesses external validity or the extent to which the results can be generalized to the population. Design evaluates internal validity, or the extent to which certain threats may systematically bias the results. Sources of heterogeneity refer to statistical conclusion validity or attention to types of conditions, settings, and respondents that may produce random heterogeneity.