Many people associate aging with the ongoing process of physical and cognitive decline. But it need not be the case. First of all, science is working on leveraging Metformin to extend our lifespan. Second of all, just 15 minutes of brisk walking every day may literally save your life. Regardless, however, it looks like as we get older, we get happier — even when we need to cope with physical ailments.
A new study by researchers at University of California, San Diego School of Medicine suggests this paradoxical trend in the mental health of aging adults. "Their improved sense of psychological well-being was linear and substantial," said senior author Dilip Jeste, MD, distinguished professor of psychiatry and neurosciences and director of the Center on Healthy Aging at UC San Diego. "Participants reported that they felt better about themselves and their lives year upon year, decade after decade."
The findings are published in this month's issue of the Journal of Clinical Psychiatry.
Conversely, Jeste and colleagues noted high levels of perceived stress and symptoms of depression and anxiety among adults in their twenties and thirties participating in the study. "This 'fountain of youth' period is associated with far worse levels of psychological well-being than any other period of adulthood," he said.
It has been broadly assumed that the mental health of older people mirrors their worsening physical and cognitive function. But Jeste said actual research, though limited, produces mixed findings.
"Some investigators have reported a U-shaped curve of well-being across the lifespan, with declines from early adulthood to middle age followed by an improvement in later adulthood. The nadir of mental health in this model occurs during middle age, roughly 45 to 55. However, we did not find such a mid-life dip in well-being."
The reasons for these differences in results aren't obvious. There is measurement variation across studies, with different researchers emphasizing different indicators that, ultimately, produce different conclusions. Nonetheless, the commonality is in finding improved well-being in the second half of life. Jeste emphasized that this study was not restricted to psychological well-being, but included "mental health," which is broader in definition and also includes satisfaction with life, and low levels of perceived stress, anxiety and depression.
Most epidemiologic studies report lower prevalence of all mental illnesses in older adults, except for dementias. "Some cognitive decline over time is inevitable," said Jeste, "but its effect is clearly not uniform and in many people, not clinically significant — at least in terms of impacting their sense of well-being and enjoyment of life."
In the latest study, Jeste and colleagues examined the physical health, cognitive function and other measures of mental health in 1,546 adults, ages 21 to 100 years, living in San Diego County, who were selected using random digit dialing. Participants were almost evenly split by gender, stratified by age decade, with an oversampling of adults older than 75 years of age.
The linear nature of the findings was surprising, said Jeste, particularly in magnitude. The oldest cohort had mental health scores significantly better than the youngest cohort, though the former's physical and cognitive function was measurably poorer than the latter's.
The reasons for improved positive mental health in old age are not clear. Some previous research has shown older adults become more adept at coping with stressful changes. They learn, said Jeste, "not to sweat out the little things. And a lot of previously big things become little." However, another important explanation may be increased wisdom with age. A number of studies have shown that older individuals tend to be more skilled at emotional regulation and complex social decision-making. They also experience and retain fewer negative emotions and memories. These are all collective elements of wisdom, as defined by the researchers.
Michael L. Thomas, PhD, first author of the paper and assistant research scientist in psychiatry at UC San Diego School of Medicine, cautioned that "like many other investigations of this type, it was a cross-sectional study, and thus a snapshot of data. Also, there may have been a survivor bias — that is, less healthy adults do not survive into old age." Yet, he also pointed out that older adults in this study were physically more disabled than younger ones — so this was not a sample of super-normal healthy adults.
Jeste expressed concern that the rates of psychological distress and mental illness in younger persons seem to be rising. "Inadequate attention has been paid to mental health issues that continue or get exacerbated post-adolescence. We need to understand mechanisms underlying better mental health in older age in spite of more physical ailments. That would help develop broad-based interventions to promote mental health in all age groups, including youth."