Association found between mental disorders diagnosed at the time of military conscription and premature death in a cohort of men over a 22-year period.
TUESDAY, Aug. 7, 2012 (MedPage Today) — Patients with conditions ranging from neurotic disorders to schizophrenia faced an increased risk of premature death, even when their disease wasn’t severe enough to warrant hospitalization, Swedish researchers determined.
Among young men diagnosed with a mental disorder at the time of military conscription, the mortality risk was almost doubled for those with depression and more than five times higher for those with bipolar disorders, according to Finn Rasmussen, PhD, of the Karolinska Institute in Stockholm, and colleagues.
And among those who were diagnosed later, at the time of hospital admission, hazard ratios for mortality ranged from 5.46 for those with adjustment or neurotic disorders to 11.2 for those with substance abuse disorders other than alcohol, the researchers reported in the August issue of Archives of General Psychiatry.
Patients with severe mental illness are known to have an increased risk for death, for various reasons including cardiovascular disease, psychosocial disadvantage, and suicide.
Most information about these concerns has derived from studies of patients with severe disorders such as schizophrenia who were hospitalized, and less has been known about risks among community-dwelling individuals with less serious illnesses.
To consider this, Rasmussen and colleagues examined the records of 1.09 million men who underwent physical and psychiatric examinations at the time of conscription for military service between 1969 and 1994. Most were about 18 years of age.
A total of 5.6 percent at that time were diagnosed with a variety of conditions including schizophrenia, bipolar disorder, depression, personality and neurotic disorders, and alcohol or other substance abuse disorders.
During a mean of 22.6 years of follow-up, 15,110 of the men died.
After adjustment for age, socioeconomic status, blood pressure and body mass index, intelligence, and education achievement, the mortality risks were elevated for all diagnoses.
“Our finding that a clinical diagnosis of a neurotic and adjustment disorder or a personality disorder during a screening examination in early adulthood was associated with an approximately two-fold risk of death, even in those with no evidence of comorbid mental illness, suggests that the mortality risk associated with mental disorder is not limited to those whose disease is severe enough to require inpatient care,” Rasmussen and colleagues observed.
Among the men diagnosed later, during hospitalizations post-conscription, 4,879 had died.
The researchers stratified this group of men according to year of conscription, and found that among men born between 1951 and 1958, there was a five to 11 times greater mortality risk for those hospitalized with mental illness compared with those without mental illness hospitalizations.
In addition, for those born between 1968 and 1976, mortality risks were seven to 29 times greater.
Even after excluding the 20 percent to 32 percent of men whose deaths were considered suicides, the mortality risk remained notably elevated, with hazard ratios of 3 to 9 in the earlier birth cohort and 4 to 17 in the later group.
A total of 60,333 men had admissions for psychiatric reasons after their conscription, 10,665 of whom had already been diagnosed at the time of conscription.
The odds ratio for early death among these men was 12.4, whereas those who were later hospitalized, but had no mental disorders at conscription, had an odds ratio of 8.45.
The greater risk for men with earlier diagnoses might reflect more severe, longstanding disease, according to the researchers.
The factors that appeared to most strongly attenuate the link between mental illness and early death were intelligence, education, and socioeconomic status in later life, the researchers noted.
Limitations of the study included the male-only population and the possibility of an underestimation of psychiatric diagnoses at conscription, since not all conscripts were referred for psychiatric evaluation.
In addition, they acknowledged that there were unmeasured factors that might have contributed to mortality risk in these analyses, including concomitant physical illnesses, diet, physical activity, adverse effects of medications, and lack of access to healthcare.
“If this huge burden of premature mortality is to be reduced, the physical healthcare of people with mental illness needs to be a greater priority for medical care professionals,” they concluded.