First, the good news: Suicide rates among younger and older Americans have been declining since the early 1990s. Now, the puzzling news: No one really knows why .
Those are the findings of a study conducted by researchers at the University of South Carolina and released Thursday (Sept. 28) in the October issue of the American Journal of Public Health.
Dr. Robert McKeown, a professor and associate dean for research at the University of South Carolina's Arnold School of Public Health, presented the findings at the forum, 'Out of the Shadows: Exploring the Barriers to Mental Health, Prevention and Treatment,' at the National Press Club in Washington, D.C.
'For 40 years adolescent suicide rates rose,' said McKeown, who collaborated on the study with the USC pharmacy professor Dr. Richard Schulz and School of Medicine neuropsychiatry professor Dr. Steven Cuffe.
'Then, the rates began to decline in the late 1980s for adults 65 and older and in the early 1990s for adolescents and young adults,' he said. 'But many people weren't aware; they kept saying suicides were increasing when it was no longer true.'
McKeown, who tracked suicide rates for research and teaching, noticed the trends had reversed and that rates were declining among adolescents, young adults (younger than 25) and older adults (65 and older). He recruited Schulz and Cuffe to explore explanations for the changes.
Their study suggests several possibilities why those suicide rates have fallen and raises questions about why suicide rates among the middle groups -- those 25 to 64 -- have not declined.
'In our medical-literature searches, we began finding international studies that suggested a correlation of declining suicide rates with an increase in the use of new-generation antidepressants,' McKeown said. 'But you can't blithely assume that drugs like Prozac have lowered the suicide rate. If that was the reason, why haven't the suicide rates of those in the 25-to-64 age brackets declined, too?'
From 1994 to 2003, suicide rates declined 30 percent in adolescents and young adults. Among older adults, the suicide rate fell 33 percent from 1987 to 2003. Despite the decline, suicide remains the third-leading cause of death among adolescents behind accidents and homicide. Among older adults, suicide is surpassed by several chronic diseases as a leading cause of death.
'We need to understand how something this significant could turn on a dime,' McKeown said.
That understanding is particularly important because the Food and Drug Administration has warned physicians about the risk of increased suicidal ideas and attempts, particularly among children, associated with certain antidepressants that are used for the treatment of depression, anxiety disorders and some types of personality disorders.
'We aren't trying to argue that these drugs are harmless,' McKeown said. 'But the possible correlation between the advent of new antidepressants and the decline in suicide rates needs to be better explored.'
Perhaps there is no association at all, he said.
'It could be that as antidepressants help a patient's depression improve, that person becomes more energetic, less apathetic and better able to make decisions,' McKeown said.
The researchers also believe that the decline in some suicide rates may have nothing to do with antidepressants but with improved medical care. For example, some of the studies they surveyed attributed the decline in American homicide rates to improved trauma care.
'It could be that the number of attempted suicides hasn't gone down. We might just have better trauma care that keeps more people alive after attempting to take their own lives,' McKeown said.
Not enough attention has been given to the trends in suicide over the last 20 to 30 years, McKeown said.
'We need a better understanding of why rates have declined significantly among adolescents/young adults and older adults in order to capitalize on factors that may be effective in prevention,' he said. 'And we need to understand better the relationship between antidepressant therapy and subsequent suicide attempts.'