Special safeguards must be implemented to protect people with mental disorders from genetic testing that would not be beneficial to that person, say the Nuffield Council on Bioethics. In their report, Mental Disorders and Genetics: the ethical context, published today (23 September, 1998), the ethical implications arising from genetic research and how the research is applied are reviewed on the basis of the fundamental need to preserve human respect and human dignity.

The report focuses on mental disorders because conditions such as schizophrenia, Alzheimer's disease, depression and anxiety, and personality disorders carry distinctive ethical, social and legal concerns that bear heavily - not only on the sufferer - but on society as a whole.

To this end, the report deals with the whole person, not simply with their genes. "In response to the recent and frequent discovery of genes associated with a variety of diseases, there is a temptation to rely on 'geneticisation' as the ultimate answer to diagnosis and prevention," said Dame Fiona Caldicott (principal of Somerville College, University of Oxford and chairman of the working party which produced the report). Mental disorders are highly complex, and to attribute the illness or a person's susceptibility to the illness to their genetic make up, distorts attitudes. For instance, men and women who consider having children may place undue emphasis on producing a perfect child rather than the importance of good parenting. Similarly, individuals who believe that their health and longevity are determined by their genes underestimate the array of social circumstances that affect mental health.

The promise of studies into the genetic basis of mental disorders will be enhanced only if research programmes are conducted in parallel with research into the social consequences of mental disorders and the interaction of genetic with environmental factors. "There are many misconceptions and fears about how the results of genetic studies will be used which are not contributing to wider public or scientific understanding of either mental disorders or genetics and which may increase the stigma attached to those with mental illness," Dame Fiona said.

Speaking at the launch of the report, held in central London today, Dr Andrew Wilkie from the University of Oxford (and also a member of the working party) described the contribution of science to the knowledge of mental disorders. Scientists' understanding of how the normal brain functions is still limited, making studies of abnormalities that much more elusive. Huntington's disease and early onset Alzheimer's disease are examples of diseases of the brain with a clear pattern of inheritance through successive generations (known as Mendelian) when a biochemical alteration - a genetic mutation - can be identified. The extent of the genetic component is not so clear cut, however, in more common disorders such as schizophrenia, manic depression or anxiety, even though they tend to run in families. "It has proved difficult to identify the individual gene location. This indicates that there is a familial clustering of variations in several genes which collectively contribute to the risk - or susceptibility - of developing one of these more common mental disorders," said Dr Wilkie.

For scientists, genetic research into mental disorders offers the potential to improve the understanding of the process of the disease that, in turn, may lead eventually to new ways of treating or even preventing some mental disorders. For the moment, at least, however, it is not likely to be useful for diagnosing or predicting the risk of mental disorders.

"Testing for genetic disorders has important ethical implications for families, adults as well as the children," said working party member, Professor Martin Richards from the University of Cambridge . In deciding whether a child should be tested, the over-riding criterion should be whether a test would be in the child's best interests. Therefore, the working party recommends that children should not be tested for carrier status or conditions that develop in adulthood. The information gained about the likelihood or otherwise of a mental disorder would profoundly affect a person and those around them. If children are tested, it denies them the possibility of making their own choice in adulthood.

Many healthy people may carry gene variants associated with mental disorders but usually not develop the condition, for example, late onset Alzheimer's disease. The working party recommends that if a genetic test cannot accurately predict a mental disorder, it should be discouraged, especially while there is no therapy currently available. "Testing allows planning and provides choices," Professor Richards said. "But those choices can be immensely difficult and are entirely personal, such as the decision over whether to continue a pregnancy."

The option of genetic counselling, therefore, to help guide people in their decisions relating to mental disorders requires specific and expert skills. The demand for testing may increase in the light of genetic information that research yields. In providing information about a disorder, however, the counsellor may inadvertently introduce a fear of stigma and challenge the integrity of the individual. The working party, therefore, recommends that research is undertaken to clarify the appropriate aims and outcomes of genetic counselling for mental disorders, together with education, training and support of primary health care teams and genetic counsellors.

Regarding the role of genetic information for insurance and employment, the working party emphasised that insurers should not exaggerate the relevance of genetic information as it relates to mental disorders. To rely on such information would be unethical and counterproductive, leading to the damaging consequences of stigma and unfair discrimination. The working party calls on the Government and the insurance industry to monitor the use of genetic tests for mental disorders to prevent unnecessarily high premiums or refusal of insurance.

People with a recognised mental disorder that does not in itself affect their ability to work often experience great difficulty in finding employment, a problem compounded by discrimination and/or stigma. It is not clear how additional genetic information on a person's susceptibility to a mental disorder would be of benefit to employers and accordingly, the report urges the Human Genetics Advisory Commission to monitor the introduction of screening programmes for employees.

In conducting research into mental disorders, the involvement of patients raises further ethical questions. The working party believes that written consent is essential when an individual is competent to make a decision and that research ethics committees should pay close attention to such research programmes. As is the case with all children, research should be subject to strict safeguards, particularly so in non-therapeutic research involving children and mentally incapacitated people. Nigel Pleming, QC, a member of the working party, said, "The central purpose of the intervention of the law or other forms of control in this difficult area must be to assist in the advance of understanding genetics, to limit any harm and suffering, and to promote respect for human beings and human dignity."