Seasonal affective disorder (SAD) and the "winter blues" could affect 10 to 15 percent of your staff. Colleagues experiencing symptoms of either can have a significant impact on those who do not.

Here are three ways understanding SAD and the winter blues can help you be a more effective leader during these cold months.

1. Heal thyself

Understand the symptoms and causes of SAD and the winter blues is the first step. Dr. Norman Rosenthal first introduced the conditions back in the 1980s, and his book on SAD provides a simple, useful infographic explaining the basics of the conditions (see below).

In general, moods decline, eating patterns take a negative turn, and sleep can become elusive or insufficient. Unfortunately, recognizing this in others may be challenging. Instead, we can take a step back and look at how winter affects our own lives to develop a compassionate eye for those around us who may be suffering.

Specifically, does it seem tougher to get out of bed when it is cold and dark? Does comfort food (like baked macaroni and cheese) sound much more appealing than health food (like kale salad) at lunch? Is caffeine showing up more times per day (coffee in the morning, more tea and hot cocoa throughout the day)?

Even without SAD or the winter blues, many of us can relate to the feelings that regularly plague sufferers.

2. Lead by example

Per Rosenthal and the National Institutes for Health, lack of sunlight is the major issue behind both SAD and the winter blues — both are also more common within families and women. Keeping this information and the symptoms in mind when we schedule team activities can help.

For example, consider holding team meetings in the morning in a conference room with lots of light. Better yet, schedule a lunch meeting nearby enough that everyone can get there without driving. On an individual level, set the stage by walking more, getting outside, eating and sharing healthy food, and talking about the challenges of winter more openly.

As leaders, we are watched by our peers and staff, it is a great opportunity to set a solid example. Plus, extra light, outside time and healthy eating are great habits that can help all of us improve our moods during the dark months of winter and beyond.

3. Provide resources

I am not a doctor, and odds are you are not either. Recognize that, and create an environment that is supportive for those who may need it. Specifically, start by understanding that more than half the population views depression as an individual weakness, and that many of those with depression try to fight it on their own.

SAD and the winter blues, as subsets of depression, may not be taken seriously by many people. Yet the symptoms of both low motivation, negative mood, fatigue, lack of interest can have a significant impact on those surrounding the sufferers.

Ensure proper resources are readily available to your team. Most employee assistance programs (EAPs) and healthcare practitioners can provide information sheets that can be posted in the break room or handed out during a team meeting. If HR is available, they can provide additional resources to help ensure staff can confidentially access appropriate assistance.

In any case, whether we suffer from a clinical condition or post-holiday fatigue combined with tough weather, everyone can benefit from leaders who understand and take active steps to recognize and support their team through the challenges of the season.