Winter Blues or Seasonal Depression? What New Yorkers Should Know About Shorter Days

Every winter, New York looks and feels different. The days grow shorter and grayer, the cold keeps people indoors, and by late December the city gets only about nine and a quarter hours of daylight, nearly six hours less than at the height of summer, according to New York sunrise and sunset data.

For many people, the season brings a familiar slump: less energy, more time under the covers, and less interest in plans. For some, it is something more serious. Here is how to tell the difference between the winter blues and seasonal depression, and what actually helps.

Winter blues vs. seasonal affective disorder

The winter blues are common. In a 2024 American Psychiatric Association poll, 41% of Americans said their mood declines in winter. People reported sleeping more, feeling fatigued, and feeling depressed during the colder months, and 61% said they feel better once spring arrives. Region matters too: in an earlier APA survey, 47% of people in the Northeast reported a winter dip in mood, compared with 26% in the West.

Seasonal affective disorder (SAD) is different. The National Institute of Mental Health describes SAD as a type of depression, not simply a low mood. About 5% of U.S. adults experience it, and the APA notes that January and February tend to be the hardest months. Clinicians generally look for symptoms that return during the same season for at least two consecutive years and then lift when the season ends.

Some people carry more risk. A clinical review of winter-pattern SAD found that women are diagnosed about four times as often as men, that it is more common in younger adults, and that rates tend to rise at more northern latitudes. New York sits squarely in that zone.

A simple way to think about it: the winter blues make life feel heavier, but you keep functioning. SAD gets in the way of work, relationships, and daily routines for weeks or months at a time.

Why shorter days can affect your mood

Researchers have not pinned down a single cause of SAD, but the leading explanation involves your internal body clock. Research on winter depression suggests that with less morning light, that clock can drift out of sync with the actual day-night cycle, most often running late. Light also has to reach the eyes to reset the clock, which is part of why gray, indoor winter days matter.

Brain chemistry plays a role too. In people with SAD, short winter days delay the normal morning drop in melatonin, the hormone that makes you sleepy, according to the National Center for Complementary and Integrative Health. Studies have also found seasonal changes in how the brain handles serotonin, a chemical tied to mood, that tracks with symptom severity.

City life can add to the effect. Long commutes underground, office days that start before sunrise, and tall buildings that block the low winter sun all cut down on the daylight New Yorkers actually see.

Signs to watch for

SAD shares many symptoms with other forms of depression, along with a few that are typical of the winter pattern. Signs flagged by the American Psychiatric Association and the National Institute of Mental Health include:

• Feeling sad, down, or hopeless most of the day

• Losing interest in activities you usually enjoy

• Sleeping much more than usual, yet still feeling exhausted

• Craving carbohydrates, overeating, or gaining weight

• Irritability and pulling away from friends and family

• Feeling worthless or guilty

• Trouble concentrating or making decisions

• Thoughts of death or suicide

One or two of these on a dreary week is normal. Several of them lasting two weeks or longer, or a pattern that shows up every fall, is a signal to take seriously.

What helps

SAD is very treatable, and several approaches have solid evidence behind them.

Light therapy. According to NIH guidance on light therapy, a light box typically delivers 10,000 lux, about 20 times brighter than ordinary indoor lighting, for 20 to 60 minutes a day. Boxes should filter out UV rays, and you should not stare directly into them. Light therapy can also trigger mania in people with undiagnosed or undertreated bipolar disorder, so check with a clinician first. Morning sessions are generally preferred.

Cognitive behavioral therapy for SAD (CBT-SAD). This form of talk therapy helps you identify and reframe negative winter thoughts, and it uses behavioral activation, which means deliberately scheduling activities that feel engaging or enjoyable. In a randomized trial of 177 adults published in the American Journal of Psychiatry, CBT-SAD and light therapy worked equally well the first year. By the second winter, depression had returned in 27.3% of the CBT group versus 45.6% of the light therapy group. In other words, the skills learned in therapy tend to last.

Medication. Antidepressants such as SSRIs can help, and bupropion is used to help prevent winter episodes in people with a history of SAD. These decisions belong with a prescribing clinician.

Everyday habits. Vitamin D on its own is not considered an effective SAD treatment, since the research is mixed. What many people find helpful is simpler. In the APA's 2024 poll, Americans named talking with friends and family and going outside among the top ways they cope with winter, and 27% said good lighting at home lifts their mood. Physical exercise has also shown benefits for mood in SAD. For New Yorkers, that might mean walking part of your commute above ground, taking lunch outside on bright days, or keeping a standing weekend plan with a friend.

When to reach out for support

Consider talking with a mental health professional if your symptoms last more than two weeks, make it hard to get through work or daily life, or seem to return every fall. Because SAD follows a predictable calendar, starting support early in the season can make the darkest months far more manageable. 

Shorter days are a fact of life in New York, but feeling stuck in the dark does not have to be. At Dr. Fallon's Practice, our licensed clinicians provide virtual therapy across New York State, using evidence-based approaches such as cognitive behavioral therapy and mindfulness-based cognitive therapy to help clients manage depression and seasonal mood changes from the comfort of home.