© 2005 The Royal College of Psychiatrists
Correspondence |
Risk reduction studies in schizophrenia
North Staffordshire Combined Healthcare NHS Trust, Greenfield Centre, Furlong Road, Tunstall, Stoke-on-Trent ST6 5UD, UK.
Correspondence: E-mail: skchatur{at}hotmail.com
Niemi et al’s (2004) report does not truly address the implications of their findings. Their clinical implications (p. 16) summarise their results, but one fails to draw clinical sense of it or be in a position to use the information in clinical practice. One could be cynical about their findings; the offspring of mothers with schizophrenia or psychotic disorders are expected to be at increased risk, which could vary across studies owing to a multitude of factors, so the findings of the study are no surprise. The increased risk could be genetic, psychosocial or both.
The clinical implications of high-risk studies ought to help identify those at high risk and prevent health problems in them. A number of studies on risk reduction strategies have been reported for common medical problems, including diabetes (Parillo & Ricardi, 2004), cardiac disorders (Ferdinand, 2004) and atherosclerotic vascular disease (Heckam & Anand, 2003) and even complex multi-factorial disorders such as hypertension (Sheridan et al, 2003), to name a few. Although little can be done about the genetic component of the risk, the psychosocial and environmental effects can definitely be minimised. Multiple appropriate lifestyle alterations and stress protective strategies may be relevant. Furthermore, one expects that over time, the more recent studies should report relatively lower rates of elevated risk compared with those done decades earlier. Incidentally, Niemi et al found an incidence of 6.7%, lower than the 16.2% found in a study reported in 1993, and 13.1% in one reported in 1995, showing a gradually decreasing receding trend. Niemi et al attribute these differences to methodological factors, but one wonders whether the reduction can be attributed to preventive measures being implemented with those at high risk, advertently or inadvertently.
What is the point of knowing that people are at increased risk of developing a disorder if nothing can be done with this knowledge?
REFERENCES
- Ferdinand, K. C. (2004) The importance of aggressive lipid management in patients at risk: evidence from recent clinical trials. Clinical Cardiology, 27 (suppl. 3), 12 –15.
- Heckam, D. G. & Anand, S. S. (2003)
Emerging risk factors for atherosclerotic vascular disease: a critical review
of evidence. JAMA, 290, 932
–940.
[Abstract/Free Full Text] - Niemi, L. I., Suvisaari, J. M., Haukka, J. K., et al
(2004) Cumulative incidence of mental disorders among
offspring of mothers with psychotic disorder. Results from the Helsinki
High-Risk Study. British Journal of Psychiatry,
185, 11
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[Abstract/Free Full Text] - Parillo, M. & Riccardi, G. (2004) Diet composition and the risk of type-2 diabetes: epidemiological and clinical evidence. British Journal of Nutrition, 92, 7 –19.[CrossRef][Medline]
- Sheridan, S., Pignone, M. & Donahue, K. (2003) Screening for high blood pressure: a review of the evidence for the US Preventive Services Task Force. American Journal of Preventive Medicine, 25, 151 –158.[CrossRef][Medline]
Author’s reply:
Department of Mental Health and Alcohol Research, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland.
Correspondence: E-mail: laura.niemi{at}ktl.fi
Dr Chaturvedi questions the clinical relevance of knowing that offspring of mothers with schizophrenia are at increased risk of developing both psychotic and non-psychotic disorders, particularly because preventive measures are not available. However, preventive measures may be available in the future. Clinical high-risk studies already suggest that using specific preventive interventions, it is possible at least to delay the onset of psychosis in patients at incipient risk of psychosis (McGorry et al, 2002). However, the criteria for being clinically at high risk require that the individual is already showing psychotic-like symptoms or impaired functioning (McGorry et al, 2002). One of the goals in high-risk studies (including ours) is to identify early indicators of emerging psychotic disorders that could be detected before any impairment starts to develop.
Family interventions are rarely targeted at children of mothers with psychotic disorders, who often remain uninformed about their parent’s illness and have to cope alone with their parent’s symptoms and take additional responsibility for the family (Valiakalayil et al, 2004). We hope that the knowledge that the children are themselves at increased risk of developing mental disorders will enhance the planning and implementation of supportive measures and parental education for families where the parent(s) suffer from psychotic disorder. Such support should begin during pregnancy and continue through childhood and adolescence. These measures could also turn out to be preventive: the Finnish Adoption Study showed that the risk of developing schizophrenia-spectrum disorders among adoptees whose biological mothers had schizophrenia was much lower if they were raised in adoptive families with ‘healthy’ rearing patterns (Tienari et al, 2004).
Finally, Dr Chaturvedi suggests that there might be a genuine decline in the risk of developing schizophrenia among high-risk children. We discussed this possibility in our article, but the method of identifying the mothers in our study differs so much from those of the Copenhagen and New York high-risk studies that we still consider it premature to draw such a conclusion.
REFERENCES
- McGorry, P. D., Yung, A. R., Phillips, L. J., et al
(2002) Randomized controlled trial of interventions designed
to reduce the risk of progression to first-episode psychosis in a clinical
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[Abstract/Free Full Text] - Tienari, P., Wynne, L. C., Sorri, A., et al
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[Abstract/Free Full Text] - Valiakalayil, A., Paulsen, L. A. & Tibbo, P. (2004) Burden in adolescent children of parents with schizophrenia. The Edmonton High Risk Project. schizophrenia. The Edmonton High Risk Project. Social Psychiatry and Psychiatric Epidemiology, 39, 528 –535.[Medline]
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