Bad boys grow up to be sick men, researchers say.
In a long-running British study of juvenile delinquency in boys, death and disability at age 48 were strongly linked to antisocial behavior in youth, according to Jonathan Shepherd of Cardiff University in Wales and colleagues.
The imbalances in mortality and disability had a range of associations, not just antisocial behavior, Shepherd and colleagues reported in the December issue of the Journal of Public Health.
In fact, the researchers were surprised "that the increase was not limited to substance abuse or other mental health problems known to be linked with an antisocial lifestyle, but included premature death and disability from a wide variety of chronic illnesses, such as heart disease, stroke, respiratory disease, and cancer," Shepherd wrote in a prepared statement.
The so-called Cambridge Study in Delinquent Development (or CSDD), which began in 1961, has followed 411 boys from a working class urban area of south London.
The original sample included all the boys ages 8 or 9 enrolled in six state primary schools within a one-mile radius of the study's research office. For the current study, 365 of the original participants were interviewed, the researchers wrote.
By age 48, a total of 17 men had died, and data on other outcomes at age 48 was available for the 365 men interviewed for the current report, Shepherd and colleagues reported.
Of the 365, Shepherd and colleagues found, 17 were registered as disabled, so that 34 of the participants were either dead or disabled at age 48.
Of the 17 who died, 13 had been convicted of a crime. Three died in accidents (one while intoxicated), two from cancer, two from unknown causes and one each from cerebral hemorrhage, stroke, bronchopneumonia, motor neuron disease, drug overdose, and suicide, the researchers reported.
One of the four not convicted of a crime had died from an industrial injury, one from a cerebral hemorrhage, one from a myocardial infarction and one from suicide, they reported.
The causes of disability were equally scattered, the researchers said. Two were disabled because of injury, and 15 as a result of illness, including seven psychological or neurological illnesses.
Further analyses revealed that six factors were associated with an increased risk of death or disability. Specifically:
Self-reported delinquency at age 32
Any antisocial behaviors at age 10
Any conviction between the ages of 10 and 40
Any parental risk factors (such as a conviction for a crime) at age 10
Conviction between the ages of 10 and 18
Impulsivity at age 18
In a statistical analysis three of those factors -- self-reported delinquency at 32, antisocial behavior at 10, and any parental risk factor at 10 -- were able to identify which participants were most at risk, the researchers reported.
"We were surprised to see such a strong link between these early influences and premature death, and this indicates that things that happen in families at age 8 to 10 are part of a progression towards dying prematurely," Shepherd said in a prepared statement.
Among its limitations, the study relies on data from a homogeneous population of white men from a single region of London and may not generalize to other populations, the researchers noted in the journal.
Other potential limitations included repeated interviews over the course of the study which may have confounded results, infrequency of interviews which may have affected recall, and lack of information about socioeconomic status over time.
The researchers also cautioned that the study provides little causal data on the link between delinquency and poor health outcomes.