predictive testing for huntington disease: a psychologist's view

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American Journal of Medical Genetics (Neuropsychiatric Genetics) 54:161-166 (1994) Invited Editorial Predictive Testing for Huntington Disease: A Psychologist’s View Seymour Kessler Department of Pediatrics, University of California, Sun Francisco, California After the discovery of genetic markers closely linked to the gene for Huntington disease (HD) on chromo- some 4 [Gusella et al., 19831,several centers in the U.S. and elsewhere began to offer a presymptomatic test for individuals at risk for this disorder. Since the mid- 198O’s, more than 1,000 persons have undergone test- ing world-wide [World Federation of Neurology Re- search Group on Huntington’s Disease, 19931, and reports from the various testing centers describing their protocols and findings and elaborating on the eth- ical, legal, and psychological problems encountered have gradually made their way into print. The two pa- pers [Codori et al., 1994; Codori and Brandt, 19941 pub- lished in this issue of Neuropsychiatric Genetics, come from The Johns Hopkins University School of Medi- cine, one of the major institutions involved with re- search and clinical services devoted to HD, and are a welcome addition to this literature. Codori et al. [ 19941have put together in one cohesive picture three diverse observations: 1) At-risk individuals have participated in predic- tive testing despite the fact that HD has no cure and no adequate treatment, and in the face of the possibility that the discovery that they carry the HD gene may worsen rather than improve the quality of their lives andor that of their families. 2) In the period before the predictive test was avail- able, several surveys showed that many at-risk indi- viduals expressed an interest in being tested [Stern and Eldridge, 1975; Barette and Marsden, 1979; Teltscher and Polgar, 1981; McCormack and Lazzarini, 1982; Tyler and Harper, 1983; Koller and Davenport, 1984; Schoenfeld et al., 1984; Kessler et al., 1987; Mar- ket et al., 1987; Mastromauro et al., 1987; Meissen and Berchek, 1987;Evers-Kiebooms,19901,yet few actually followed through with testing; in one instance only about 10% of at-risk individuals who had access to pre- dictive testing availed themselves of the test [Quaid and Morris, 19931. Received for publication February 10, 1994; revision received Address reprint requests to Seymour Kessler, Ph.D., P.O. Box March 15,1994. 7702, Berkeley, CA 94707. 0 1994 Wiley-Liss,Inc. 3) Among persons who have participated in predic- tive testing for HD there has been a relatively low rate (at least so far) of psychiatric fallout. Largely, the se- quelae have been among disorders classified in DSM 111-R [Diagnostic and Statistical Manual of Mental Dis- orders, 19871 as adjustment disorders. No one, to my knowledge, has committed suicide because they were found to have an increased risk for HD, and the fre- quency of psychiatric hospitalizations among tested individuals is about 2% in the U.S. [Quaid, 19931. Codori et al. [19941 tie these observations together by suggesting the possibility that the cohort of at-risk persons who have participated in predictive testing programs is comprised of self-selected individuals with relatively good psychological functioning, persons who tend to perceive themselves as being capable of dealing with “bad” news from the test. Their data confirm find- ings of other investigators [Crauford et al., 1989; Jacopini et al., 1992; Simpson et al., 1992;Tibben et al., 1993a1, indicating that individuals who do not proceed with testing tend to perceive themselves as being less capable of dealing with a positive test outcome (or in- creased risk), or possibly feel inadequate to deal with the anxieties that the testing protocols may engender. Conversely, test participants perceive themselves as being able to cope with the situation. The difference between utilizers and nonutilizers of predictive testing appears to be in a factor psycholo- gists once called ego-strength [Barron, 19531,which dif- ferentiates individuals with relatively good self-con- cepts from those with poorer self-concepts. The former tend to have better developed interpersonal skills, as well as the ability to tolerate anxiety and to persevere in the face of adversity; the latter tend to have less well developed social skills and have difficulties managing their fears and anxieties. Wiggins et al. [19921 argue that the psychologically positive outcomes of predictive testing for HD may be due to the counseling and support provided before, dur- ing, and following testing. This assertion is probably true. However, we must not discount or fail to credit the individuals who have volunteered to undergo testing. Their self-perceptions and evaluations, their good judg- ment and resiliency, and their particular coping skills appear to have played a key role in determining the

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Page 1: Predictive testing for huntington disease: A psychologist's view

American Journal of Medical Genetics (Neuropsychiatric Genetics) 54:161-166 (1994)

Invited Editorial

Predictive Testing for Huntington Disease: A Psychologist’s View

Seymour Kessler Department of Pediatrics, University of California, Sun Francisco, California

After the discovery of genetic markers closely linked t o the gene for Huntington disease (HD) on chromo- some 4 [Gusella et al., 19831, several centers in the U.S. and elsewhere began to offer a presymptomatic test for individuals at risk for this disorder. Since the mid- 198O’s, more than 1,000 persons have undergone test- ing world-wide [World Federation of Neurology Re- search Group on Huntington’s Disease, 19931, and reports from the various testing centers describing their protocols and findings and elaborating on the eth- ical, legal, and psychological problems encountered have gradually made their way into print. The two pa- pers [Codori et al., 1994; Codori and Brandt, 19941 pub- lished in this issue of Neuropsychiatric Genetics, come from The Johns Hopkins University School of Medi- cine, one of the major institutions involved with re- search and clinical services devoted to HD, and are a welcome addition to this literature.

Codori et al. [ 19941 have put together in one cohesive picture three diverse observations:

1) At-risk individuals have participated in predic- tive testing despite the fact that HD has no cure and no adequate treatment, and in the face of the possibility that the discovery that they carry the HD gene may worsen rather than improve the quality of their lives andor that of their families.

2) In the period before the predictive test was avail- able, several surveys showed that many at-risk indi- viduals expressed an interest in being tested [Stern and Eldridge, 1975; Barette and Marsden, 1979; Teltscher and Polgar, 1981; McCormack and Lazzarini, 1982; Tyler and Harper, 1983; Koller and Davenport, 1984; Schoenfeld et al., 1984; Kessler et al., 1987; Mar- ket et al., 1987; Mastromauro et al., 1987; Meissen and Berchek, 1987; Evers-Kiebooms, 19901, yet few actually followed through with testing; in one instance only about 10% of at-risk individuals who had access to pre- dictive testing availed themselves of the test [Quaid and Morris, 19931.

Received for publication February 10, 1994; revision received

Address reprint requests to Seymour Kessler, Ph.D., P.O. Box March 15,1994.

7702, Berkeley, CA 94707.

0 1994 Wiley-Liss, Inc.

3) Among persons who have participated in predic- tive testing for HD there has been a relatively low rate (at least so far) of psychiatric fallout. Largely, the se- quelae have been among disorders classified in DSM 111-R [Diagnostic and Statistical Manual of Mental Dis- orders, 19871 as adjustment disorders. No one, to my knowledge, has committed suicide because they were found to have an increased risk for HD, and the fre- quency of psychiatric hospitalizations among tested individuals is about 2% in the U.S. [Quaid, 19931.

Codori et al. [19941 tie these observations together by suggesting the possibility that the cohort of at-risk persons who have participated in predictive testing programs is comprised of self-selected individuals with relatively good psychological functioning, persons who tend to perceive themselves as being capable of dealing with “bad” news from the test. Their data confirm find- ings of other investigators [Crauford et al., 1989; Jacopini et al., 1992; Simpson et al., 1992; Tibben et al., 1993a1, indicating that individuals who do not proceed with testing tend to perceive themselves as being less capable of dealing with a positive test outcome (or in- creased risk), or possibly feel inadequate to deal with the anxieties that the testing protocols may engender. Conversely, test participants perceive themselves as being able to cope with the situation.

The difference between utilizers and nonutilizers of predictive testing appears to be in a factor psycholo- gists once called ego-strength [Barron, 19531, which dif- ferentiates individuals with relatively good self-con- cepts from those with poorer self-concepts. The former tend to have better developed interpersonal skills, as well as the ability to tolerate anxiety and to persevere in the face of adversity; the latter tend to have less well developed social skills and have difficulties managing their fears and anxieties.

Wiggins et al. [19921 argue that the psychologically positive outcomes of predictive testing for HD may be due to the counseling and support provided before, dur- ing, and following testing. This assertion is probably true. However, we must not discount or fail to credit the individuals who have volunteered to undergo testing. Their self-perceptions and evaluations, their good judg- ment and resiliency, and their particular coping skills appear to have played a key role in determining the

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162 Kessler

outcomes seen so far. Barron [1953] and others suggest that individuals with relatively better psychological ad- justment (or high ego-strength) may also profit from counseling more than persons with lower ego-strength. Thus, the person X procedure interaction may be the key to the adaptive adjustments seen so far.

OTHER FACTORS IN SELF-SELECTION One factor which may contribute to the low rate of

utilization of predictive testing for HD concerns the ar- duous protocols used by some centers. In addition to a neurological examination, participants are required to undergo extensive psychological testing and psychi- atric evaluations, and sometimes to complete multiple questionnaires covering knowledge parameters and at- titudes towards a broad range of topics. This generally requires repeated visits to the center by a prospective participant, usually accompanied by an ancillary indi- vidual; in several centers, as many as four or more such visits are required. At another center [Fox et al., 19891, investigators estimated that each participant would have to undergo 3 hr of face-to-face pretest counseling and 2% hr of psychological testing. From the con- sumer’s viewpoint, this may be overkill, excessively de- manding of their time, money, and physical and emo- tional energy. In the Johns Hopkins study, 42% of the group that declined to be tested said that they found the protocol too daunting [Codori et al., 19941. Thus, whatever else such protocols accomplish, they seem to act as a screen to discourage all but the most motivated or determined individuals to proceed with the test.

Another variable not intensively studied by the groups offering linkage testing, but which may limit the participation of some at-risk individuals in predictive tests, has been the need of gathering blood samples from other family members. This requires the potential participant to engage oneself in interactions and family “politics,” dynamics which may not always yield cooper- ation or satisfaction, and which the at-risk individual desiring testing may want to avoid. With the recent de- velopment of a direct test for the HD gene [Huntington’s Disease Collaborative Research Group, 19931, only a blood sample from the participant is needed, and thus the necessity of dealing with potentially troubling or troublesome family dynamics in order to obtain relevant samples from others will largely be obviated. This alone may lead to a significant change in, the composition of the cohort coming for predictive testing in the future.

BENEFITS AND COSTS OF PREDICTIVE TESTING

Codori and Brandt [1994] point out that predictive testing has both psychological benefits and costs. One of the major benefits they found was the reduction of anxiety due to the uncertainty of not knowing whether or not one has inherited the HD gene. This ubiquitous uncertainty among at-risk persons tends to penetrate into, and have an impact on, almost all the major areas of life functioning [Wexler, 19791. Information from pre- dictive testing has helped some individuals and couples make reproductive and other decisions based on knowl- edge rather than on wishful thinking.

Among the costs of predictive testing were an in- crease of worry, a sense of burden of having, so to speak, let the genie out of the bottle (nearly half of the in- creased risk group in the Johns Hopkins study felt this), and of guilt a t having placed their children at risk for HD. Individuals who received low risks from testing and who had affected sibs or ones with increased risks tended to feel guilty about their good fortune. Partners of tested persons tended to bear a disproportionate share of the burden of finding out that the latter will become affected with HD [Tibben et al., 1992; Kessler, 19931. In several cases, Codori and Brandt [1994] re- ported that after predictive testing, the marriages of test participants did not survive.

Even among individuals who received an increase of risk for HD, few in the Johns Hopkins study regretted having taken the predictive test. For at-risk individu- als with children who received a reduced risk for HD from testing, invariably there was a sense of relief that the latter would be spared the angst and terrors of be- ing at risk for this disorder. All in all, the Johns Hop- kins studies are in agreement with studies from other centers [Wiggins et al., 1992; Tibben et al., 1993b,c] in suggesting that so far the net benefits outweigh the costs of predictive testing.

The apparently low rate of major psychiatric seque- lae among individuals who have undergone predictive testing may delude the professional community into be- lieving that such testing is an innocuous procedure which should be treated with no more precaution or concern than any other laboratory test (e.g., cholesterol or blood sugar determinations, etc.). This might have the potential for enormous tragedy for at-risk individu- als and their relatives. Hayden [1991] and other work- ers in the field argue that predictive testing for such disorders as HD may inflict not inconsiderable psycho- logical harm upon at-risk persons and their relatives, especially since no intervention exists to mitigate the inexorable degenerative progress of the disorder. Again, I remind the reader, so far it looks like a rela- tively psychologically well-adjusted group has pro- ceeded through predictive testing. It might be a mis- take to believe that when more problematic persons pursue predictive testing, as they surely will now that direct testing for the HD gene is available, psychiatric casualties can be kept to the relatively low levels cur- rently achieved.

DIRECT TESTING FOR HD We are at a turning point with regard t o predictive

testing for HD. The various centers at which linkage testing was offered are currently retooling to provide the more direct test. Some centers are already offering the latter test, and more presumably will enter the test- ing arena [Nance et al., 1991; Bennett et al., 19931. This may be an opportunity to reassess many things, in- cluding testing protocols, research strategies, counsel- ing procedures, etc., to ascertain what has worked and what has not.

Protocols As I understood it, the original intent of the demand-

ing protocols instituted at the major testing centers

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age the various research groups to publish case reports, similar to those in Huggins et al. [19921 and Bloch et al. [19921, with an eye to providing details so that others with differing theoretical orientations might have a basis upon which to draw their own conclusions.

One thing geneticists have already discovered is that their preconceived notions about what constitutes “good” and “bad news may require reexamination. A lowered risk for HD from predictive testing is not al- ways perceived in a positive way by some individuals, particularly when their expectations and/or conscious or unconscious wishes have not been confirmed. Such disappointments often have psychological conse- quences, including depression, increased anxiety, etc. Many individuals who have lived under the shadow of HD for much of their lives, often organize their beliefs, life activities, and cognitivelaffective functioning into a cohesive system geared, among other things, to learn- ing that they carry the HD gene.’ When contrary infor- mation is given to challenge these organized systems, enormous internal reorganization is required to adapt to the new circumstances and status (this is a common problem seen in the course of psychotherapy). This re- organization often does not occur quickly, and in fact may be resisted for a long period of time, since long- held beliefs tend to dominate our thinking even in the face of contradicting evidence [Ross and Anderson, 19821. Anxiety and feelings of loss often accompany these efforts to adapt, and disbelief is not an uncommon response.

In my own work with persons undergoing predictive testing for HD, I have experienced many of the same things Codori and Brandt [19941 report here. Many in- dividuals who received so-called “good news from test- ing, although elated at first, had emotional difficulties as they came face to face with their limitations, as unanticipated psychological issues surfaced, as they dealt with the lost opportunities of the past, and as they had to answer the question, “Okay, what now?” In some cases, complicating their efforts to adapt, were (in my judgment) the inappropriate or thoughtless responses of other family members to the participants’ test re- sults. Some sibs of the latter were irritated as they mis- takenly thought their own risks for HD were increased. Others scoffed at and belittled the participants’ efforts and feelings, and some relatives were rejecting in re- sponse to what they perceived as violations of implicit family rules. In some instances, relatives did not react at all to the participants’ news, as if to trivialize it. Quaid [1992] and Tibben et al. [1992] report similar experiences at their centers.

Regardless of how relatives might react to the partic- ipants’ news, the latter have a relational history which

was to identify and screen out persons with a high risk for psychiatric distress and disorder. To what extent have the various protocols served this purpose? If the protocols are also designed for research purposes and if they lead to a self-selection of participants, as the Johns Hopkins data suggest they might, then how rep- resentative will the collected data be of the overall at- risk population? This question may have critical impli- cations if one plans to make policy decisions on the basis of the findings. One might also ask, how effective have the counseling components of the various proto- cols been in preparing the participants for the test and its aftermath? What aspects of counseling need to be strengthened in the future? How effective have fol- lowup efforts been and how can these be made more effective? If the direct test for HD becomes subject to greater demand, consumers might become less tolerant of the arduous protocols some centers currently use; there is a growing impression that some individuals are already shopping around for laboratories with minimal costs and demands. This might create pressures on all centers to simplify their protocols. How might this be accomplished without diminishing the quality of services in the process?

Research Chapman 119921 has argued persuasively for the

need for research on the psychosocial aspects of predic- tive testing. Some of the research she recommends would require a major multidisciplinary approach with a long-term commitment of funds and personnel re- grettably far beyond the means of current testing cen- ters. As things are shaping up, there appear to be at least three major centers of research on predictive test- ing for HD: the Johns Hopkins group, which appears to take a cognitivehnformation processing approach, the Vancouver, British Columbia group which seems to be psychodynamically-oriented, and the Netherlands group, which takes an approach combining psychody- namic thinking with cognitive elements. Although there may be minor differences of emphasis and of in- terpretation, the work emanating from these groups largely points in a similar direction. Furthermore, their findings are consistent with those of the broader litera- ture dealing with stress and coping. Whenever re- searchers have stumbled, usually it was due to short- comings in their assumptions about human behavior. The work in progress is largely promising. However, I would like to suggest several things. First off, investi- gators should specify the underlying psychological as- sumptions upon which their research strategies are based. This might help them place their findings into a wider context in so far as the literatures on stress and coping are concerned. This might also avoid the appearance of a “Let’s see what happens” research approach, which seems to be prevalent in some of the work. Second, I would urge investigators to pay greater attention to systems factors, since predictive testing has a major ripple effect on relatives and friends of test participants. Third, I would suggest greater attention to social desirability effects, particularly in interpret- ing self-report ratings. Also, I would strongly encour-

For some, obtaining a positive test outcome or an increased risk for HD is experienced as a relief; the other shoe has finally dropped. Individuals with high dependence needs often have the fantasy that becoming affected with HD might lead to the care- taking they yearn for. Some significant others of persons found to not carry the HD gene may be profoundly disappointed since they might have organized their lives on the assumption that they will be caregivers [Huggins et al., 19921.

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colors their interpretation of the former’s behavior. In one case known to me, when a woman who received a decreased risk from testing told her mother about the results, the latter told her how worried she had been. The woman heard these remarks as proof of her moth- er’s self-centeredness and lack of support. Codori and Brandt [ 19941 are correct to point out that predictive testing may create or exacerbate, as well as alleviate, problems for at-risk persons.

COUNSELING ISSUES Quaid [19921 advances a thoroughgoing discussion of

the counseling issues encountered in predictive testing for HD. Likewise, Codori and Brandt [19941 advance recommendations for counseling professionals based on their own experiences. Most of these recommendations I can endorse. But I have some reservations when they recommend that counselors describe to potential test participants the experiences of “real people” who have preceded them in the testing.2 Every person who goes through predictive testing is, in my view, unique in many ways, certainly in life history and in ways of cop- ing with life. Each person is just “as real” as any other. In their individual ways, they are filled with anxiety, fear, and fantasies about what fate has in store. I am concerned that we may unwittingly substitute anoth- er’s experiences for the participant’s own, thus inter- fering with the latter’s process of self-discovery. Also, we might communicate that there is a right and wrong way to act and respond, and this is simply not true.

I would like to make some additional suggestions to genetic counselors and other professionals involved in predictive testing, which have a bearing on all the is- sues discussed here. Codori and Brandt [1994] point out that after testing, in response to questionnaires, participants tended to endorse items relating to real- izations about the importance of life, to a desire to travel, to make plans, to change many aspects of their functioning, to prioritize their lives and to live life to the fullest, etc. In my experience identical statements are frequently made before testing when the person is asked about their motivations to take the test, and what their thoughts are if the test should show that they carry the HD gene. On inquiry, I find that most of these statements tend to have little substance, and too frequently one is left feeling that many participants are far less prepared for the implications of predictive test- ing than they present themselves to be. Much of what passes as “reasons” or “motivations” for pursuing pre- dictive testing seems to be ephemeral fantasies and wishes. Few individuals seem to be able to articulate

Usually, when asked in pre-test counseling, “How have others reacted to the test?”, I try to focus on the person’s anxieties and uncertainty and, if appropriate, provide them with encourage- ment, emphasizing that others have gone before them to face these uncertainties and survived, and that they will likely do so also. “War stories” or statistics about others often are not com- forting or encouraging. Also, we need to be mindful that all the consequences of predictive testing are not yet known.

what motivates them to proceed with testing (couples whose reproductive plans are dependent on test out- comes are a notable exception) without entering the realms of fantasy and wishful thinking. The reasons given for desiring testing, including the resolution of the uncertainty of not knowing, tend to be rather lim- ited. Inquiries about the persons with whom they have discussed their decision to be tested often reveal that key individuals have not been consulted, that the amount of time spent in discussing the decision and its implications, if done at all, tends to be minimal. The responses to questions of what will be done if the test reveals the person to be a gene-carrier also often turn out to be unrealistic in terms of the preson’s economic and emotional resources3. Some potential participants thought that an increased risk for HD would improve relations within their families, suggesting that there were troubled relations to begin with. Several had the belief that they would attain a closeness with other family members once the test was over. These, too, are wishes and fantasies which, as Codori and Brandt [19941 correctly point out, could be realized whether or not the person took the predictive test. In other instances, participants said that adverse test results would lead to changes in their financial or other plans but, on further inquiry, it became clear that they did not seem to understand or appreciate the intermediary steps necessary to accomplish such changes. Given the enormous difficulties we all have in making changes and adjustments in our lives, even when we know we should, it would not be surprising if most of these pretest intentions and plans remain, over time, largely unfulfilled fantasies.

These comments should not be taken as criticism of at-risk persons, but rather as an acknowledgment of how difficult it is for anyone to prepare in advance for adverse events which have profound personal and interpersonal implications, are threatening to the person’s health and integrity, and are so filled with anx- iety and fear at every step of the way. This is why pretest psychological counseling and follow-up must re- main a central aspect of predictive testing programs. Counseling may help individuals and their significant others prepare for the anxieties and implications of testing, tasks difficult to accomplish on one’s own be- cause of their emotionally evocative nature. Whatever approach the counselor takes, some amount of stress inoculation [Janis, 1958; Meichenbaum, 19771 may be inevitable. In this procedure the participant is exposed to information and is guided to consider and think aloud about what it might “. . . be like to experience the

For example, one young man said that he would spend the next few years traveling around the world if he was found to have the HD gene. When it was pointed out that that might require considerable money, more than he possibly had, he admitted that he did not know what he would do should he receive a positive test outcome. In short, travel was a fantasy that allowed him to avoid dealing head on with the awesome implications of this outcome, and the realities he might then have to face. Counselors might consider that travel may be a metaphor for distancing oneself emotionally from anxiety-provoking thoughts and images.

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Bloch M, Adams S, Wiggins S, et al. (1992): Predictive testing for Huntington disease in Canada: the experience of those receiving an increased risk. Am J Med Genet 32:217-224.

Chapman MA (1992): Canadian experience with predictive testing for Huntington disease: lessons for genetic testing centers and policy makers. Am J Med Genet 42:491498.

Codori AM, Brandt J (1994): Psychological costs and benefits of pre- dictive testing for Huntington’s disease. Am J Med Genet 54: 174-1234,

Codori AM, Hanson R, Brandt J (1994): Self-selection in predictive testing for Huntington’s disease. Am J Med Genet 54: 167-173.

Crauford D, Dodge A, Kerzin-Storrar L, Harris R (1989): Uptake of presymptomatic predictive testing for Huntington’s disease. Lancet 5603-605.

American Psychiatric Association (1987): “Diagnostic and Statistical Manual of Mental Disorders,” Third ed. revised. Washington, DC: American Psychiatric Association.

Evers-Kiebooms G, Cassiman JJ , Van der Berghe H (1990): Attitudes towards predictive testing in Huntington disease: a recent survey in Belgium. J Med Genet 24:275-279.

Fox S, Bloch M, Fahy M, Hayden MR (1989): Predictive testing for Huntington disease: I. Description of a pilot project in British Co- lumbia. Am J Med Genet 32:211-216.

Gusella JF, Wexler NS, Conneally PM, Naylor SL, Anderson MA, Tanzi RE, Watkins PC, Ottina K, Wallace MR, Sakaguchi AY, Young-, Shoulson I, Bonilla E, Martin JB (1983): A polymorphic DNA marker genetically linked to Huntington’s disease. Nature 306:234-238.

Hayden MR (1991): Predictive testing for Huntington disease: are we ready for widespread community implementation? Am J Med Genet 40:515-517.

Huggins M, Bloch M, Wiggins S, Adam S, Suchowersky D, Trew M, Klimek ML, Greenberg CR, Eleff M, Thompson LP, Knight J , MacLeod P, Girard K, Theilmann J , Hedrick A, Hayden MR (1992): Predictive testing for Huntington disease in Canada: ad- verse effects and unexpected results in those receiving a decreased risk. Am J Med Genet 42508-515.

Huntington’s Disease Collaborative Research Group (1993): A novel gene containing a trinucleotide repeat that is expanded and un- stable on Huntington’s disease chromosome. Cell 72:971-983.

Jacopini AG, DAmico R, Frontali M, Vivoan G (1992): Attitudes of persons at risk and their partners toward genetic testing. Birth Defects 28: 113-1 17.

Janis IL (1958): “Psychological Stress.” New York John Wiley. Janis IL (1982): Decisionmaking under stress. In Goldenberger L,

Breznitz S (eds): “Handbook of Stress.” New York The Free Press, pp 69-87.

Kessler S (1993): Forgotten person in the Huntington disease family. Am J Med Genet 48:145-150.

Kessler S, Field T, Worth L, Mosbarger H (1987): Attitudes of persons at risk for Huntington disease toward predictive testing. Am J Med Genet 26:259-270.

Koller WC, Davenport S (1984): Genetic testing in Huntington’s dis- ease. Ann Neurol 16:511-512.

McCormack MK. Lazzarini A (1982): Attitudes of those at risk for

expected negative consequences of the chosen course of action.” [Janis, 19821. Exposure to and mastery of dis- quieting, anxiety-provoking thoughts in a safe, con- trolled environment is believed to help the person deal with the distressing realities later on. It provides an op- portunity for the person to anticipate losses, to grieve, to rehearse their actions, and to make realistic plans that will enable them to cope more effectively in the months and years ahead.

THE FUTURE We do not know what the future may bring and what

major changes might be possible if and when a cure or treatment for HD can be found. Under such conditions, the context of predictive testing will be entirely differ- ent from what it is today, especially in the hope it holds out for at-risk individuals and their relatives. Predic- tive testing would take on different meaning for test participants.

Whether or not the self-selecting process reported by Codori et al. [1994] will continue in the future is not known. I have the impression that since the develop- ment of the direct test, more individuals with clinical and subclinical aspects of HD are asking to be tested, and referrals from physicians in order to make or con- firm the diagnosis of HD have increased. In addition, a small number of persons who have already been through linkage testing are also asking to be retested using the direct procedure. Inevitably discrepancies be- tween the findings of the two procedures will arise and will require technical and psychological reconciliations. Hopefully this will be rare. In any case, even if some self-selection continues, and hopefully it will, because of the changing focus of testing for the HD gene, from prediction to confirmation, one should expect the na- ture of the cohort undergoing testing to change with it.

CONCLUSION As it is currently carried out, predictive testing for

HD is probably a mixed blessing. As individuals with increased risk for HD gradually become affected over the years ahead, a clearer picture of the actual benefits and costs of predictive testing will undoubtedly emerge. For those persons who are found to carry the HD gene, the value and benefits of advance knowledge remain to be seen. It may turn out that the significant others and relevant family members, rather than the test partici- pants, may be the relatively greater beneficiaries of this information. Considering everything, an underly- ing faith continues to exist among many professionals in the field, as well as among many in the at-risk com- munity, that the net benefits of predictive testing for HD will prove to be worthwhile.

REFERENCES Barette J , Marsden CD (1979): Attitudes of families to some aspects of

Huntington’s chorea. Psychol Med 9:327-336. Barron F (1953): An ego-strength scale which predicts response to psy-

chotherapy. J Consult Clin Psychol 17:327-333. Bennett RL, Bird TD, Teri L (1993): Offering predictive testing for

HuntinPton disease in a medical genetics clinic: practical applica-

Huntington’s’disease toward presymptomatic provocative testing. N Engl J Med 305:1406.

Markel DS, Young AB, Penney JB (1987): At risk persons’ attitudes to- ward presymptomatic and prenatal testing of Huntington disease in Michigan. Am J Med Genet 26:295-305.

Mastromauro C, Myers RH, Berkman B (1987): Attitudes toward presymptomatic testing in Huntington disease. Am J Med Genet 26:271-282.

Meichenbaum D (1977): ”Cognitive-Behavior Modification: An Inte- grative Approach.” New York Plenum Press.

Meissen GJ, Berchek RL (1987): Intended use of predictive testing by those at risk for Huntington disease. Am J Med Genet 26: 283-293.

Nance MA, Leroy BS, Orr HT, Parker T, Rich SS, Heston LL (1991): Protocol for genetic testing in Huntington disease: three years of experience in Minnesota. Am J Med Genet 40:518-522.

_ _ Quaid KA (1992): Presymptomatic testing for Huntington disease: rec- tions. J-Genet Counsel 2:123-137: ommendations for counseling. J Genet Counsel 1:277-302.

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166 Kessler

Quaid KA (1993): Presymptomatic testing for Huntington disease in the United States. Am J Hum Genet 53:785-787.

Quaid KA, Morris M (1993): Reluctance to undergo predictive testing: the case of Huntington disease. Am J Med Genet 45:4145.

Ross L, Anderson CA (1982): Shortcomings in the attribution process: on the origins and maintenance of erroneous social assessments. In Kahneman D, Slovic P, Tversky A (eds): “Judgment Under Uncertainty: Heuristics and Biases.” Cambridge: Cambridge Uni- versity Press, pp 12S152.

Schoenfeld M, Myers RH, Berkman B, Clark E (1984): Potential im- pact of a predictive test on the gene frequency of Huntington’s chorea. Am J Med Genet 18:423429.

Simpson SA, Besson J, Alexander D, Allan K, Johnston AW (1992): One hundred requests for predictive testing for Huntington’s dis- ease. Clin Genet 41:326-330.

Stern RS, Eldridge R (1975): Attitudes of patients and their relatives to Huntington’s disease. J Med Genet 12:217-223.

Teltscher B, Polgar S (1981): Objective knowledge about Huntington’s disease and attitudes towards predictive tests of persons at risk. J Med Genet 18:31-39.

Tibben A, Vegter-vd Vlis M, Skraastad MI, Frets PG, Kamp JJP, Niermeijer MF, Ommen GJB v, Roos RAC, Rooijmans HGM, Stronks D, Verhage F (1992): DNA-testing for Huntington disease in the Netherlands: a retrospective study on psychosocial effects. Am J Med Genet 44:94-99.

Tibben A, Frets PG, Kamp JJP vd, Niermeijer MF, Vegter-vd Vlis M, Roos RAC, Ommen GJB v, Duivenvoorden HJ, Verhage F (1993a):

Presymptomatic DNA-testing for Huntington disease: pretest atti- tudes and expectations of applicants and their partners in the Dutch program. Am J Med Genet 48:10-16.

Tibben A, Duivenvoorden HJ, Vegter-vd Vlis M, Niermeijer MF, Frets PG, vd Kamp JJP, Roos RAC, Rooijmans HGM, Verhage F (199315): Presymptomatic DNA testing for Huntington disease: identifying the need for psychological intervention. Am J Med Genet 48: 137-144.

Tibben A, Frets PG, Kamp JJP van de, Niermeijer MF, Vegter-van der Vlis M, Roos RAC, Rooymans HGM, Ommen GJB van, Verhage F (1993~): On attitudes and appreciation 6 months after predictive DNA testing for Huntington disease in the Dutch program. Am J Med Genet 48:103-111.

Tyler A, Harper PS (1983): Attitudes of subjects at risk and their rel- atives toward genetic counselling in Huntington’s chorea. J Med Genet 20:179-188.

Tyler A, Ball D, Craufurd D (1992): Presymptomatic testing for Huntington’s disease in the United Kingdom. Brit Med J [Clin Resl

Wexler NS (1979): Genetic “Russian roulette”: the experience of being a t risk for Huntington’s disease. In Kessler S (ed): “Genetic Coun- seling: Psychological Dimensions.” New York Academic Press, pp

Wiggins S, Whyte P, Huggins M, Adam S, Theilmann J , Bloch M, Sheps SB, Schechter MT, Hayden MR (1992): The psychological consequences of predictive testing for Huntington’s disease. N Engl J Med 327:1401-1405.

304:1593-1596.

199-220.