Educational initiatives for practicing psychiatrists must be developed to ensure their competence in the application of genetic testing. While pharmacogenomic probe studies are leading to the safer and more effective use of psychiatric drugs, for patients to benefit from this research requires that clinicians learn how to appropriately use pharmacogenomic testing.
The Psychiatric Genomics Course at the Mayo Clinic was developed in 2002 to update both practicing psychiatrists and psychiatric residents on the clinical implications of recent genomic research. The annual course consists of 34 hours of CME credit and is given over the course of 5 days. The course begins with the first day devoted to a review of basic molecular genetics and progresses to systematically define how genetic variation is associated with psychiatric diagnosis and treatment. On the second day, the course highlights psychiatric pharmacogenomic research that provides the evidence base for the prediction of antidepressant and antipsychotic drug responses using clinical genotyping. Pharmacogenomic testing is one of the first illustrations of the clinical utility of genomic research for psychiatric practice. On the morning of the third day, the genetics of the major psychiatric illnesses are systematically presented while the afternoon is devoted to visiting the clinical molecular genetics laboratory and learning about genomic web sites using our computer laboratories. On the fourth day, the genomics of eating disorders, addictive disorders, attention deficit hyperactivity disorder, and autism are covered, and a series of clinical cases are discussed with a focus on relevant ethical issues. At the course dinner that evening, the results of the post-course questionnaire are explored using an audience interactive methodology that allows participants to easily express their opinions anonymously and have the results immediately shown on a screen for the group to discuss. The final morning of the course is devoted to the presentation of new research findings and to the consideration of the implications of new technologies for clinical practice.
The current study was designed to investigate prevailing attitudes toward genetic testing among mental health professionals taking the course in order to better understand possible barriers that might negatively influence the adoption of new genomic technologies. The goal was to use a novel strategy for assessing professional opinion by incorporating systematic inquiry directly within the context of a continuing education program.
The primary goal of the Psychiatric Genomics Course is to teach the basic principles of genomic technology to psychiatrists and other mental health professionals. However, the course also provides an opportunity to explore current attitudes about the uses of genetic testing in providing care to patients. Participants (N=41) of the 2005 course completed both pre- and post-course questionnaires designed to investigate attitudes about the value and appropriate use of clinical genotyping. The pre-course questionnaire collected information about the participants, whether they had been genotyped, and their opinions about clinical genetic testing. The post-course questionnaire evaluated their opinions about clinical genetic testing after participating in the course. Participants were aged between 30 and 85 with a mean age of 52.5 years. There were 16 women and 25 men. Participants were primarily psychiatrists or other physicians interested in psychiatric diagnosis and treatment (see Table 1). The religious affiliations of participants are listed in Table 2.
The questionnaires contained 13 multiple-choice questions designed to address three conceptual issues. The first set of questions assessed the perceived value of pharmacogenomic testing. The second set of questions assessed attitudes about how pre-symptomatic and diagnostic genetic tests should be used. The third set of questions assessed attitudes about the age at which genetic information should be shared with children and adolescents. The survey questions are listed in Table 3.
1. Would participants choose to be genotyped?
The 2D6 gene and the 2C19 gene code for two enzymes in the cytochrome P450 family. These enzymes are involved in the metabolism of many psychotropic medications (1). Only 5% of participants knew their 2D6 or 2C19 genotype at the time that they took the course. However, by the end of the course, a majority of participants (59%) replied that they would be willing to pay for 2D6 and 2C19 genotyping at the current cost of $375. Most of participants (95%) who did not know their genotype responded that they would choose to be tested if the genotyping was available at no cost through participation in a research project.
2. Under what conditions should individuals be able to learn that they may be genetically predisposed to an illness?
Two series of scenarios were presented in which a patient requests that he or she be genotyped. The first series of questions addressed Huntington’s disease and the second series addressed Alzheimer’s disease. Participants were asked to decide whether the physician should order the test that the patient had requested.
Given that the gene that causes Huntington’s disease is virtually completely penetrant, identification of aberrant forms of the gene indicate that a patient will eventually develop the disease in his later years if he lives long enough. In each of the three Huntington’s disease scenarios, the maternal grandmother of the patient had been diagnosed with Huntington’s disease and the mother of the patient had decided that she did not want to be genotyped for the huntingtin gene. These three scenarios all address one specific ethical issue. If the patient tests positive for an aberrant form of the huntingtin gene, this outcome would reveal that her mother also must have this aberrant form of the gene and that she too will ultimately develop Huntington’s disease.
In the first scenario, the patient is 25 years old and would like to tell her fiancé if she is predisposed to the illness. Over 80% of participants thought that, under these circumstances, it was appropriate for the physician of this patient to order the test.
In the second scenario, the patient is only 16 years old. Furthermore, she reports that she feels that she must tell her fiancé whether she will develop the illness. Her mother disagrees with this decision and feels that her daughter is too young to know. Under these circumstances, only 20% of participants indicated that the physician should order the test. Three factors had changed. First, the patient was a minor. Second, she did not have the permission of her mother. Third, the question was written in such a way that some respondents felt that the patient was ambivalent about knowing her genotype and was being somewhat coercively influenced by her fiancé.
In the third scenario, a 16-year-old patient is simply curious about her predisposition and has the support of her mother in requesting the test. In this case, 43% of participants thought that her physician should order the test despite the fact that the patient was a minor and that she had no immediate need to make a decision that would have long term consequences.
The second series of scenarios explored values related to testing the APOE genotype, which is associated with the development of Alzheimer’s disease. This genotyping has not been routinely used to assess the degree of risk for developing the disease. Based on association studies, patients with one copy of the APOE*4 allele are at increased risk for developing the disease and those with two copies are at even higher risk (2). In the first scenario, a 50-year-old man, with a mother who has Alzheimer’s disease, requests to learn whether he has the APOE*4 genotype prior to making a decision about a major financial investment that would require his personal involvement for 10 years. Most participants (80%) believed that his physician should order the test. In the second scenario, a 21-year-old man, who had a grandfather who died of Alzheimer’s disease, has just inherited $100 million. He has decided to donate $10 million to medical research and plans to donate the money to Alzheimer research if he is predisposed to the disease himself. A smaller majority of participants (60%) believed that his physician should order the test under these circumstances.
3. At what age should individuals have the right to know their genotype?
Virtually all of the participants (98%) believed that adults generally have the right to know their genotypes. A majority of participants (63%) believed that parents generally have the right to know the genotypes of their children while the children are still minors. A similar majority (67%) felt that teenagers, aged 13 to 18, should have the right to know their genotype if they either have parental permission or are emancipated minors. A minority (29%), however, reported that school-aged children of 6 to 12 years have the right to know their genotypes if they have parental permission.
4. Responses associated with religious affiliation
Participants who reported a Catholic or Protestant religious affiliation were significantly less likely to believe that teenagers and children have the right to know their genotypes when compared with participants with different religious affiliations. For example, only 48% of Catholic and Protestant participants believed that teenagers, ages 13 to 18, had the right to know their genotype with parental permission, while 89% of participants with other religious affiliations felt that they had this right (p<0.005).
5. Differences associated with age of participants
The age of participants also had a significant effect on attitudes toward the rights of parents to know the genotypes of their children. While a large majority (83%) of participants younger than 50 years of age believed that parents had the right to know the genotypes of their minor children, only 45% of the participants who were older than 50 held this opinion (p<0.02).
6. Differences associated with the sex of participants
A single sex difference emerged in responses to the scenario of a young man wanting to know his APOE genotype before donating funds to medical research. In this case, a majority of male participants (76%) supported his request for genotyping, while only a minority of female participants (40%) felt that this genotyping would be appropriate (p<0.03).
The results of this questionnaire reflect the opinions of a group of mental health clinicians who had just completed 34 hours of continuing medical education specifically designed to help them understand clinical and ethical issues related to both pharmacogenetic testing and diagnostic tests. While the results cannot be generalized to broader categories of clinicians, the responses of these well informed and sophisticated participants are nevertheless of considerable interest. First, a majority of the participants felt that personal genotyping of their 2D6 and 2C19 genes would be of value and replied that they wanted to be tested themselves and were willing to pay the current cost of the genotyping. When participants were given the opportunity to be genotyped at no cost, 95% of the participants indicated that they would be tested. Given that 2D6 and 2C19 genotyping had only been easily available for clinical use for a few years at the time of the survey, only a small minority of participants had been tested. These responses suggest that these informed participants had decided that this genotyping had considerable clinical utility.
The exploration of testing for Huntington’s disease provides new insights into the perception of clinicians about the value of genotyping for this condition. A large majority of the participants felt that an adult woman should have access to her huntingtin genotype even if there was a chance that the knowledge of her own genotype might inadvertently lead to her mother learning about her genotype. This opinion is consistent with recent empirical reviews that have found that the psychological risks of huntingtin genotyping are modest. For example, one review found that patients who learn they do have a pathological variant of the huntingtin gene experience no increase in long-term psychological distress in comparison to similar at-risk patients who learn they do not have the huntingtin gene (3). Related reviews have found that even though there is an increased incidence of suicide in Huntington’s disease patients in comparison to the general population, this risk is not related to genotyping, and some evidence suggests genotyping may actually decrease the risk of suicide (4, 5).
If the patient was a minor, participants were more cautious about genetic testing for Huntington’s disease. Only 20% felt that a patient should be allowed knowledge of her genotype if she was a minor and her mother objected to her knowing this information. However, more participants (43%) supported the genotyping of a 16-year-old patient when her mother approved of testing, even in a situation in which she had no immediate need to make a long term decision.
The results from the two scenarios designed to elicit attitudes about testing for the APOE*4 allele reflected considerable support for this testing. A large majority of participants (80%) felt that a 50-year-old individual, who was approaching the usual age of onset of the disease, should be allowed to know his genotype. When considering a younger individual with many years of life ahead of him before the probable onset of the disease, approximately three-quarters of the male participants still felt that he should be tested, while only a minority of the women considered this to be appropriate. During the group discussion of the results of the survey, some of the participants expressed the opinion that the reason that they did not endorse either request for APOE testing was that they did not believe that variation in this genotype was sufficiently predictive of Alzheimer’s disease to warrant this testing. Given their opinion of the value of the test, they did not support the request of patients who felt that having a better understanding of their genetic predisposition to a disease was valuable despite not being definitive. Further clarification of the degree to which physicians felt that they should be making these kinds of decisions for their patients would be an important area of inquiry for subsequent surveys of physician attitudes.
Finally, it is interesting to note that three quarters of participants ages 30 to 50 felt that parents should have access to the genotyping results of their children, where only slightly less than half of participants older than 50 felt this to be the case. This may reflect the fact that those younger adults may be parents who are more likely to be responsible for the health care decisions of their children. In contrast, older adults may be less likely to have this responsibility. An alternative consideration could be that younger adults may be more sophisticated about recent genetic advances and assess the clinical benefits of genotyping to be greater than their older colleagues.
In summary, clinicians who were enrolled in an intensive 5-day course focused on psychiatric genomics had a range of beliefs regarding when patients should receive genotyping results. A large majority of participants felt that genotyping of drug metabolizing enzyme genes is of value and that in most circumstances adults should be permitted to know their genotype. These results also illustrate that continuing medical education programs provide an underutilized opportunity to develop a better understanding of the perspectives of practicing clinicians. These results should not be generalized to reflect the views of all psychiatrists in practice, as the participants were a subset of psychiatric clinicians with a specific interest in learning about advances in the translation of genomic research to clinical practice.
It would be important to survey a more representative sample of psychiatrists to be able to document the range of beliefs about genetic testing and to replicate the findings related to age, gender, and religious affiliation. Assessing the attitudes of participants in future continuing medical education courses devoted to training psychiatrists how to use genetic testing would also allow for the evaluation of changing attitudes over time.