An editorial in the January 2006 issue of the Psychiatric Bulletin reviews the evidence for the effectiveness of gene-based smoking cessation packages, and asks whether they are appropriate for psychiatric patients.
It is well known that the prevalence of smoking among psychiatric patients is far higher than in the general public (70% v. 30%). Smoking in schizophrenia and depression is thought in part to be an attempt to self-medicate symptoms of the illness.
There is also preliminary evidence to support a relationship between eating disorders and smoking, with smoking being used to control weight.
As clinicians working with patients with such high smoking rates, psychiatrists have a duty of care to protect them from the harmful effects of tobacco smoke. This involves informing patients of the best treatment available, and directing them to the appropriate services.
The mainstays of current smoking cessation treatment are nicotine replacement therapy (patches, gum, inhalers, lozenges and spray) and bupropion (Zyban), although behavioural support is also effective.
Gene-based tests for smoking cessation are currently marketed privately to smokers via the internet to help inform them whether they carry gene variants predisposing them to nicotine addiction. The results are given with a personally tailored plan to stop smoking, including medication, behavioural changes and alternative therapies.
Should psychiatric patients be advised to purchase gene-based tests? There are several issues to be considered:
- Genetic association studies are inconclusive with regard to the best genetic candidates in the smoking cessation field
- The responsibilities of general adult psychiatrists, substance misuse service professionals and general practitioners are already significant, without the additional burden of informing themselves about, and providing counselling on, gene-based therapies
- The cost implications for the NHS of this added duty is of concern
- Current privacy laws within the UK fail to protect patients from the misuse of genetic information. Many European countries have laws preventing insurers and prospective employers from gaining access to an individual's genetic profile. When patients spend money on a genetic test for smoking cessation, they are inadvertently generating information about their risk of predisposition to developing or possessing a number of other stigmatising conditions, such as alcohol or cocaine addiction, or pathological gambling
- The majority of people who attempt to give up smoking using genetic tests will fail -success rates are as low as 20% in a year
- Information provided to patients from the test may mislead them into thinking they have a particularly virulent or 'genetic' form of addiction, and are never going to be able to give up.
The authors of the editorial conclude that more research is needed to verify the usefulness of genetic tests for smoking cessation, especially among general medical and psychiatric patients.
Until there is greater understanding of the genetic influences in nicotine addiction, patients being cared for in psychiatric services are best advised to avoid such tests.