On a raw, dreary January day, Susan welcomed a visitor to her Woodford County horse ranch with warmth and engaging conversation. It was an effort, she said.

“The way I’m acting now is the way I am in summer,” said Susan, 60, who called herself “the poster child” for SAD, or Seasonal Affective Disorder.

Without the hours of strong sunlight that winter months steal, she and other SAD sufferers – an estimated 10 percent of the northern hemisphere’s population – slip into depression at levels mild to severe.

“On days like this,” Susan said as she glanced through her kitchen window at bare fields draped by low, dark clouds, “I’m as lazy as a slug. I don’t feel peppy, don’t feel happy, don’t call friends.”

That’s been the story of her adult life. She was diagnosed with SAD about 20 years ago, at roughly the same time the medical community formally recognized the still-mysterious malady. 

Susan (who asked that her last name remain confidential) retired several years ago after 20 years as an intensive care nurse at a Peoria hospital. She and her husband tend horses they own and board on their 12-acre complex several miles southeast of Eureka. She loves the place they bought a year ago with the same passion she brought to her high-stress career.

While that work helped energize her through past winters, as fall would settle in she’d tell her friends, “I’m sorry, I hibernate, and you won’t hear from me. 

“I’m a totally different person in the summer. I’m outside all the time, riding every day,” she said. But on these January mornings, “especially on a day like this, I have to mentally kick myself to do the chores, to get out and feed the horses.” 

Two decades ago, “I finally asked myself, what in the world is wrong with me?” and began looking for answers. 

By the early ‘80s, studies had begun to show that some forms of depression – later identified as SAD – were eased with light therapy. Susan’s doctor recommended it for her, but its effects were minimal.

That was her fault, at least in part, she said. She struggled to find the patience “to sit for 20 minutes hunched over” an oval-domed therapy lamp at her table.

While light therapy has become more focused and refined over the years. Susan said she treats her SAD with a different approach.

Studies have linked SAD with low levels of Vitamin D, which the skin produces when in contact with light. Susan takes regular, low-level doses of the vitamin in pill form.

It’s a “controversial” form of therapy, she said, and could be dangerous. “If (vitamin D) is taken too much it becomes toxic.”

Susan said she has better days than others during winter’s gloom. She knows she should get outside as much as she can, a true effort “on days like this.”

But she knows the chores are waiting and that spring will come.

Follow Michael Smothers at Twitter.com/msmotherspekin

A related story on SAD can be found by clicking here.