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A C T A I ' S Y C ' l l l A 7'RlC'A .S(',AA'l~l." c'liil ISSN 0902-4441

Editorial

Can suicide research lead to suicide prevention? This issue of Actu Psychiutricu Scundinuvicu adds four papers to the scientific literature on suicide and suicidal behaviour. The four studies arc good examples of the different levels of observation in suicide research. Kalediene's study (1) of time trends in suicide mortality in Lithuania exemplifies macro- epidemiological studies linking societal changes and upheavals to concurrent changes in suicide rates. The study by Jessen et al. (2) links variations in suicide attempts to events of everyday life (in this case public holidays), the paper by Vijayakumar & Rajkumar ( 3 ) studies risk factors for suicide at the individual level, and the study by Nasser & Overholser (4) attempts to discriminate subgroups among suicide attempters. All of these studies in one way or another address suicide predictors. Most researchers in this field would, if asked about the relevance of their research, probably answer that identification of risk factors is crucial in order to point out preventive measures. However, there appears to be a large gap in the literature on suicide. On the one hand, there is an extensive literature replicating many of the key findings with regard to risk factors for suicide. In the last year alone Medline includes almost 400 references to studies of risk factors and the epidemiology of suicide and suicide attempts. On the other hand, there is little empirical knowledge of which preventive interven- tions may be effective in either high-risk groups such as psychiatric patients or suicide attempters, or in the population in general.

The reason for this lack of knowledge is probably due to the extreme difficulties that treatment evaluation research in suicide prevention would face. The low baseline rate of suicide and the low rate of suicide in any high-risk group would require enormous study samples and a long duration of follow-up in order to achieve sufficient statistical power. For example, in groups of high-risk psy- chiatric patients with more than 100-fold increased risk, only a few per cent of the patients will actually commit suicide within a year. This means that it is

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This issue of Actu Psychiatrica Scandinavica also includes a short biography of Preben Bo Mortensen.

difficult to document any reduction produced by an intervention, and it also means that any intervention should be highly acceptable to the 97 -99% of patients who would not commit suicide irrespective of the intervention. How then can onc proceed?

One example of a quasi-experimental design that might be useful in the future is the Gotland study ( 5 ) , in which a training programme for general practi- tioners was implemented on a Swedish island. This study has of course been criticized, and is too small to stand alone, but replications in other settings, possibly increasing the sample size and using a randomized epidemiological design in which differ- ent regions are randomized into different preventive programmes, may provide some of the evidence needed to guide decision-makers on suicide preven- tion. Likewise, studies aimed at psychiatric patients, especially during particularly vulnerable periods, e.g. just after discharge from a psychiatric service (6, 7), could be conducted along similar lines.

Lewis et al. (8) pointed out that suicide prevention might be better aimed at reducing exposure to risk factors rather than targeting any particular high-risk group. In my opinion, the main target risk factor would be mental disorder. In a recent study we found that half of all suicides in Denmark are committed by people who have been admitted to a psychiatric hospital, and almost 30% were committed by people who had been admitted during the last year (9). This, together with other studies which have found that most suicides in a population are committed by people suffering from mental disorder (e.g. lo), would suggest that improved diagnoses and treatment of mental disorders would be a reasonable strategy in order to prevent suicides in the general population. Again, one must bear in mind that in any high- risk group only a small proportion of individuals will commit suicide within a limited time period, meaning that services should be acceptable and if possible also with other beneficial effects in addition to reducing suicide risk. However serious and important a problem a suicide may be, it might be more productive to view it as the extreme end of a quality of life scale, which would mean that suicide preventions could be regarded as an

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Editorial

important spin-off of general improvements in mental health services.

Suicide research has advanced far enough to guide choices of preventive efforts. The next important step will be to evaluate them.

Acta Psychiatrica Scandinavica Prehen Bo Mortenscn

Invited Guest Editor

References

KALEDIENE R. Time trends in suicide mortality in Lithuania. Acta Psychiatr Scand 1999;99:419~422.

suicide and major public holidays in Europe: findings from thc WHO/EURO Multicentre Study on Parasuicide. Acta Psychiatr Scand 1999;99:412 41 8. VIJAYAKUMAR L, RAJKUMAK S. Are risk factors for suicide universal? A casc-control study in India. Acta Psychiatr Scand 1999;99:407 41 1 .

JI:SSL:N G, J E N S ~ N BF, ARENSMAN E ct al. Attempted

4. NASSER EH. Assessing varying degrees of lethality in depressed adolescent suicide attempters. Acta Psychiatr

5. R ~ H M E R Z, RUTZ w, PII-1LGREN H. Dcpression and suicide on Gotland. An intensive study of all suicides before and after a depression-training programme for general practitioners. J Affect Disord 1995;35: 147- 152.

6. GOIDACRE M, SEAGROAI'T v, HAWTON K. Suicide after discharge from psychiatric inpatient care. Lancet 1993;342:283-286.

7. ROSSAU CD, MORTENSEN PB. Risk factors for suicide in schizophrenic patients. A nested case-control study. Br J Psychiatry 1997;171:355 359.

8. LEWIS G, HAWTON K, JONES P. Strategies for preventing suicide. Br J Psychiatry 1997;171:351- 354.

9. MORTENSEN PB, AGERBO E, ERIKSON T, Q i N P, WESTERGKRD-NIELSEN N. Psychiatric illness and other risk factors for suicide in Denmark. Br Med J 1999 (in press).

10. HENKIKSSON MM, ARO HM, MARTTUNEN MJ et a]. Mcntal disorders and comorbidity in suicide. Am J Psychiatry 1993;150:935 -940.

Stand 1999;99:423-431.

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