Prevention of Mental and Behavioural Disorders

Prevention of Mental and Behavioural Disorders

The potential and possibilities for prevention of mental and behavioural disorders have increased substantially in recent years. This paper provides a brief review of the place of prevention within the overall public health strategy for mental and behavioural disorders, summarizes the current evidence for generic prevention interventions, and makes suggestions on how these can become part of policy and practice. For further information, the reader is referred to two publications produced by the World Health Organization (WHO).

Universal, selective and indicated preventive interventions are included within primary prevention. Universal prevention targets the general public or a whole population group that has not been identified on the basis of increased risk. Selective prevention targets individuals or subgroups of the population whose risk of developing a mental disorder is significantly higher than average, as evidenced by biological, psychological or social risk factors. Indicated prevention targets high-risk people who are identified as having minimal but detectable signs or symptoms foreshadowing mental disorder or biological markers indicating predisposition for mental disorder, but who do not meet diagnostic criteria for disorder at that time.

Secondary prevention seeks to lower the rate of established cases of the disorder or illness in the population (prevalence) through early detection and treatment of diagnosable diseases. Tertiary prevention includes interventions that reduce disability, enhance rehabilitation and prevent relapses and recurrences of the illness. This paper focuses on primary prevention of mental disorders.

The distinction between mental health promotion and mental disorder prevention lies in their targeted outcomes. Mental health promotion aims to promote positive mental health by increasing psychological well-being, competence and resilience, and by creating supporting living conditions and environments. Mental disorder prevention has as its target the reduction of symptoms and ultimately of mental disorders. It uses mental health promotion strategies as one of the means to achieve these goals. Mental health promotion, when aiming to enhance positive mental health in the community, may also have the secondary outcome of decreasing the incidence of mental disorders. Positive mental health serves as a powerful protective factor against mental illness. However, mental disorders and positive mental health cannot be described as the different ends of a linear scale, but rather as two overlapping and interrelated components of a single concept of mental health. Prevention and promotion elements are often present within the same programmes and strategies, involving similar activities and producing different but complementary outcomes.


Building the evidence base for Prevention of Mental and Behavioural Disorder:

The call for evidence-based prevention and health promotion has triggered an international debate among researchers, practitioners, health promotion advocates and policy makers. Paraphrasing the definition of evidence-based medicine by Sackett et al, evidencebased prevention and health promotion is defined as the "conscientious, explicit and judicious use of current best evidence in making decisions about interventions for individuals, communities and populations to facilitate the currently best possible outcomes in reducing the incidence of diseases and in enabling people to increase control over and to improve their health". Evidence from systematic research aims to avoid uncertainty in decisions due to lack of information, or decisions based on biased assumptions, which might in turn lead to wasting time and resources or investing in interventions with detrimental outcomes.

In supporting decision making, the use of scientific evidence becomes especially important when the implications of a decision are large, such as the choice of a new preventive programme for national implementation. Given the high costs and the pressure for accountability in spending public money, such a decision needs to be based on solid evidence, showing that the programme works and can produce a return in investment. For this, the use of evidence on the cost-effectiveness of given interventions is also crucial.

Different dimensions need to be taken into account when estimating the value of scientific evidence. First, evidence needs to be evaluated in terms of its quality, defined by the appropriateness of used research methods, to avoid biased observations and invalid conclusions. Several metaanalyses have found higher effect size in studies that use research designs rated as high in quality. Secondly, the value of the outcomes themselves, including the strength and type of effects, will also have to be appraised. Thirdly, the value of scientific evidence should be evaluated in terms of its actual use and impact for decision making. Finally, the value of the evidence will have to be combined with other indicators, also essential when considering the dissemination or adoption of prevention programmes, such as the transferability, feasibility and adaptability of programmes to other situations or cultures.

In evaluating the quality of the evidence, probably one of the "hottest" issues in the debate is whether randomized controlled trials (RCTs) should be considered the best design to warrant internal validity in complex interventions. Although the strength of RCTs is widely recognized and used in prevention research, many scientists in this field have expressed serious objections to accept this design as the one and only gold standard. RCTs are designed to study causal influences at individual level using mono-component interventions in a highly controlled context and thus are primarily suitable for evaluating clinical or preventive interventions at individual or family level. Many preventive interventions address whole schools, companies, communities or populations. They use multi-component programmes in a dynamic community setting, wherein many contextual factors are hardly controllable. The strict RCT design does not fit well in this context and, to retain its advantages in the context of community interventions, randomizations must be done at larger unit levels such as school classes, whole schools or communities. However, the feasibility of such randomized community designs is limited for practical, political, financial or ethical reasons. In those cases where, for example, ethical objections impede the use of randomization, quasi-experimental studies, using matching techniques to reach comparability between experimental and control groups, and time-series designs offer valuable alternatives.

The building of the evidence base requires a stepwise and incremental approach applying different methods depending on the information needed for a given decision. International exchange of evidence through common databases is essential for developing a strong evidence base, and for understanding the impact of cultural factors.

Source of Article: National Center for Biotechnology Information 

Visit: Dr. A. Kalyan Chakravarthy, Psychiatry Specialist.