This is the first attempt to calculate survival curves and standardised death rates for schizophrenia and related psychoses in an epidemiologically complete cohort of admissions from the late 19th and early 20th centuries. It enables us to explore contemporary causes of mortality in a way not possible for other studies, and to assess whether death rates in schizophrenia are getting worse over time.
The survival analysis shows the absolute mortality in the historical period was higher than today, but historical SMRs overlap the SMRs for patients reported in recent studies. The actual years of life lost in our historical cohort are less than those lost now.5
The main hazard of asylum care for younger people, particularly women, a century ago lay in the risk of contracting tuberculosis. Another hazard was lethal catatonia which seems likely to have accounted for most deaths from exhaustion.22
The SMR we report for schizophrenia at the end of the first year of admission is higher than the SMR from the historical cohort but is consistent with reports showing increased death rates for patients with psychotic disorders in the first year of admission today,23
and reports indicating this stems primarily from suicide.1
Our contemporary SMR at 5 years for all psychoses moreover overlaps rates reported in other studies.10
This combination of findings brings out the value of a cohort study and the importance of diagnosis. When the data are examined by diagnosis and time from first admission, the findings reveal patterns not apparent in cross-sectional studies. Cross-sectional studies miss the impact of first admissions which account for less than 15% of admissions for psychosis.
The data on suicide in the historical and contemporary samples are strikingly different. In the historical records, it was mandatory for the admitting clinician to record suicide risk and 25% of the historical patients at admission had threatened or attempted suicide. The lack of subsequent suicides raises a number of questions. Was there a bias against a diagnosis of suicide? In the case of historical patients admitted for severe depressive disorders, a number are clearly recorded as dying from suicide and as attempting suicide both in the asylum and soon after discharge so that there was no reticence about recording such verdicts for other patients at this time.24
Furthermore, the case notes of patients dying from tuberculosis and other causes contain clinical details consistent with these diagnoses. A bias against recording suicide verdicts in the schizophrenia group can probably be ruled out.
To suicide you need to have opportunity to commit suicide. The registration of suicidal tendencies in the historic cohort meant that patients were monitored. Both schizophrenic and affective disorder patients were monitored, but affective disorder patients went on to commit suicide at expected rates whereas the schizophrenic patients did not. In addition, the monitoring of patients in the asylum was by the same methods used today. There was not an undue restriction of liberty by today's standards. Historical patients with schizophrenia spent 99% of their time at liberty working on the hospital farm, in the knitting rooms or kitchens, with ample opportunity to commit suicide.
A second issue is whether patients today are more severely ill than a century ago. This seems unlikely for a number of reasons. First, the more malignant psychoses (hebephrenic and catatonic schizophrenia) were present in the historical cohort but have close to disappeared now. Second, historical patients were detained compulsorily whereas many patients today are voluntary admissions; it is therefore easier for less severely ill patients to get admitted now. Third, patients today have immediate access to medication that for many can be expected to mitigate the most distressing aspects of their disorder. In the case of catatonic syndromes, benzodiazepines eliminate the disorder now, while a higher proportion of these patients died in hospital historically than for any other form of psychosis (60%, see ).
The importance of the historical cohort in this study is that it demonstrates that suicide is not an inherent risk of schizophrenia. The historical data suggest that there is something about the modern delivery of care that contributes to suicide as an outcome. If suicide risk is not inherent in the illness, another possibility lies in deinstitutionalisation. As in our data, Mortensen and Juel1
flagged up the incident year of a schizophrenic illness as problematic. They suggest the high rates of suicide at this time might stem from deinstitutionalisation. However, more recent Nordic data argue against deinstitutionalisation as the cause of the problem, as life expectancies have slightly increased (or at least not fallen further) as deinstitutionalisation has progressed,11
and suicide rates have fallen rather than got worse.25
Moreover, contemporary patients with schizophrenia had a mean duration of admission lasting weeks rather than months and hence institutionalisation cannot have set in.
Patients who have schizophrenia are also subjected to stigma, and lack of family support. It has also been argued that antipsychotics can restore insight and this might lead to suicide. It would clearly be difficult to discount these possibilities if the suicides were happening 5 or 10 years into the illness. But the fact that suicides happen in the first year, before stigma has set in, or supports have been lost, make such factors less likely to be sole determinants of suicides.
Men are in general more likely to commit suicide than women, and in the contemporary schizophrenia sample there was a twofold greater rate of male admissions than in the historical cohort, but the increased suicide rate in the contemporary sample does not stem from this source in that in the contemporary schizophrenia sample there was a greater proportion of female than male suicides.
Suicide in schizophrenia is likely to be multifactorial in origin. One contributory factor may be treatment. A high rate of suicide in the first year of treatment, across diagnostic groups, is consistent with an initial exposure of vulnerable individuals to the dysphoric effects of antipsychotics. The elimination of individuals at risk to such effects would produce precisely the drop in SMR over time found in our study. The antipsychotics are in fact the only element of the picture to have been shown in placebo-controlled trials to be linked to an excess of suicides in psychosis, although the data are of poor quality.26
A recent observational study has also linked benzodiazepine usage to suicidal deaths in psychotic patients.27
Wahlbeck et al11
report SMRs for suicide from national cohorts of patients recruited in Denmark, Finland and Sweden of 20.6 for men and 36.6 for women. These figures map on to the suicide-specific SMR for schizophrenia reported here for years 1–10 of follow-up (35). Removing all suicides from the contemporary cohort gives an SMR for schizophrenia of 1.1 (95% CI 0.01 to 6.4), and of 1.9 (95% CI 1.0 to 3.4) for all psychoses.
An SMR of 1.9 maps onto figures cited for mortality in schizophrenia drawn from samples that contain subjects later in the trajectory of their illness. The deaths in these other studies have been linked to an increase in risk from cardiovascular causes. Our data support this. We have found high death rates in the contemporary patients with acute and transient psychoses (F23) (). Our data are consistent with other studies.2
In this group over half the mortality stems from cardiovascular causes (B).
Two observations stem from this. First, patients with acute and transient psychoses often get diagnoses of schizophrenia. Studies that do not distinguish between these two groups will lead to increased estimates of cardiovascular risk in schizophrenia. Second, it is older patients in our acute and transient cohort who died from cardiovascular causes. Their average age of death was 63 years. Consistent with this, cardiovascular deaths also featured prominently in the contemporary cohort in patients with delusional disorders (F22), where the average age at death was 74 years. Age is therefore a significant contributor to cardiovascular deaths.
Placebo-controlled trials of antipsychotics in the elderly show an excess of mortality primarily from cardiovascular causes in those on active treatment.15
The debate about using antipsychotics in the elderly has focused primarily on their use in dementia patients but our figures suggest the risk may apply in all older subjects.
These data have implications for projected years of life lost in patients with schizophrenia. Our data open up the possibility that estimates based on diagnoses that fail to distinguish between schizophrenia and acute and transient psychoses or delusional disorders may substantially overestimate the years of life lost in schizophrenia proper. For instance all cancers in the contemporary cohort came from the delusional disorder or acute and transient psychosis group. This raises the possibility that these cancers antedated and contributed to the development of rather than stemmed from these mental disorders or their treatment.
While data from the contemporary cohort offer no support for psychosis or its treatment as a cause of cancer, the incidence of gastrointestinal cancers is a striking feature of the historical data. There was only one breast cancer and no lung cancers, while 28 of the 32 cancers were related to the gastrointestinal tract. The official mortality figures for 1910 do not categorise mortality in terms of specific cancers to the extent that would permit a conclusive analysis of these data but it is worth noting that in 1910 the commonest cancers in England and Wales were of the mouth, gut and abdominal organs. Ovarian and breast cancers were commoner than found in our sample. Cancers of other bodily systems were filed under other, and were comparatively rare.
A majority of hospitalised patients with suspected cancers had postmortems and it is possible that a proportion of the increased frequency of cancer diagnosis is an artefact of postmortems. There was, however, concern about food adulteration in the 19th and early 20th centuries raising questions about possible links between this and gastrointestinal cancer as an outcome.
In summary, this study reports elevations in SMRs in schizophrenia and related psychoses over a century with the modern data in some respects worse than the historical data. While it is fashionable to look at mortality as an outcome, it must be emphasised that patients today live outside the asylum. When the antipsychotics were introduced, the benefits of recovery and discharge were widely viewed as warranting a potential reduction in life expectancy.28
Other studies have suggested that patients with schizophrenia are dying prematurely because of lifestyle factors and lack of access to healthcare resources, leading to calls for interventions in these domains. In contrast, the current data point to different hazards arising at different periods of risk, allowing differential interventions. The most striking figure in this study is that eliminating suicide in schizophrenia would restore life expectancy to normal. Checking for dysphoric responses to medication, and being willing to change medication if indicated, is worth pursuing as it might offer one of the greatest possible public health gains in any area of medicine at minimal cost.