My beautiful, fiercely independent grandmother Audrey has always been one of the most positive forces in my life, even as she has endured the death of my grandfather and most of her friends. At the same time, she has faced such mounting challenges as the gradual loss of her hearing and, more lately, the affront of having to walk with a cane. But now, on the eve of her 94th birthday, her vision has deteriorated to the point that she’s having trouble reading her beloved newspaper every morning. For the first time, she seems sort of depressed.

Watching Grams struggle to keep up with the family-dinner chitchat on a recent trip home, I couldn’t help but wonder whether the particular trials of growing older — from the death of loved ones to gradual declines in health, self-sufficiency and control — inevitably lead to this unhappy outcome.

The short answer is that aging does seem to make us more vulnerable to depression, but it’s not a foregone conclusion.

“Even though so many things happen as we get older — lots of losses and physical changes — most people weather those by adapting, and adapting without becoming depressed,” says Susan Lehmann, director of the Geriatric Psychiatry Day Hospital at the Johns Hopkins Hospital. There’s a difference, she adds, between feeling profoundly lonely or blue and true clinical depression, which is a mood state involving physical and behavioral manifestations that does not shift easily.

Lehmann notes that research has shown that major depression occurs in about 2 percent of people 65 and older, while minor depression strikes about a quarter of them, with the number even higher in nursing homes. All forms of the disease can be debilitating: “It might be called minor depression, but it can have a major impact on functioning and quality of life, so we really need to take any signs of a problem seriously,” she stresses.

Depression is much more common in women than men from puberty all the way through the mid 80s, Lehmann says, when occurrence evens out. It’s also worth noting that while heredity can play a role in depression at any age, it seems to be much less of a factor than cardiovascular and other changes in the brain as we get older. “We believe that other biological factors rather than genetics or family history seem to be important in late-life depression,” she says, noting, for example, that imaging studies have found small changes in the white matter of some elderly brains, possible evidence of mini strokes that may be related to depression.

Other medical conditions can also play a role: “Diabetes doubles the risk for depression, and depression may even be a risk factor for developing diabetes — they are feeding each other,” says Lehmann, adding that there’s a similar relationship between depression and coronary heart disease.

Be on the lookout

So how do you know if your parents or grandparents have a real problem, as opposed to fleeting sadness or loneliness? They probably aren’t going to scream “I need help” from the rafters.

“Depending on the generation, culture or context, elderly patients are much less likely to talk about or report a depressed mood,” says Lorenzo Norris, medical director of psychiatric services at the George Washington University Hospital. “This generation, particularly patients now in their 80s and older, grew up at time when the prevailing attitude was ‘You pick yourself up by your bootstraps, keep your chin up and keep your problems quiet,’ so there can be an element of shame, of being afraid that people will think you are ‘crazy’ and also thinking that depression is in one’s head or a sign of personal weakness. They don’t think of it as a neurobiological illness, like most younger people do; they think of it as something you just knuckle up and get over.”