Most people expect seasonal depression to announce itself as sadness. It usually does not start that way. For many people, the first changes are in sleep, appetite, and energy, and those changes can begin weeks before mood drops.
This post lists those early signs in plain language, explains when seasonal depression tends to start and how long it lasts, and describes the point at which a hard winter has become something a psychiatrist should evaluate. If you are reading this in early fall and some of it sounds familiar, that is a good reason to keep reading, not a reason to panic.
When seasonal depression starts
Winter pattern seasonal depression follows the calendar. According to the National Institute of Mental Health (NIMH), symptoms usually begin in the late fall or early winter and go away during the spring and summer. In Colorado, that most often means a slow start between late September and November, the hardest stretch in January and February, and a lift in March or April.
The exact weeks vary from person to person, and they tend to be consistent for the same person year after year. Someone whose slump began in mid-October last year will often feel it begin in mid-October again.
The timing matters because it is one of the clearest clues. A low stretch that starts after a job loss or a breakup can happen in any month. A low stretch that arrives on roughly the same weeks each year, as the days get shorter, is a pattern worth paying attention to.
A smaller number of people have the opposite pattern, with depression that shows up in late spring or summer. That is a real condition with its own signs, and we cover it separately on our summer depression page.
The early signs (before the mood drops)
These are the changes people most often describe in the weeks before they would call themselves depressed. None of them alone means seasonal depression. Several of them together, arriving on schedule, are worth noticing.
- Sleeping more but waking unrefreshed. Nine or ten hours in bed, and still tired at breakfast.
- An afternoon crash. Energy that holds until about 2 p.m. and then falls off, most days.
- Carbohydrate and sugar cravings. Wanting bread, pasta, and sweets in a way that feels different from ordinary hunger.
- Weight change. Usually a gain of a few pounds over the fall, tied to the cravings above and less movement.
- Canceling plans. Saying yes to things and then backing out, more and more often, because it feels like too much effort.
- Trouble concentrating. Rereading the same paragraph, losing the thread in meetings, taking longer to finish routine tasks.
- Irritability. Snapping at family or coworkers over things that would not normally bother you.
NIMH lists oversleeping, overeating with carbohydrate cravings, weight gain, and social withdrawal as the symptoms specific to winter pattern seasonal depression. The list above is those same symptoms in everyday words.
One useful habit in early fall is to write the date next to any of these that you notice. A list with dates is far more useful to a psychiatrist than a general sense that October was hard.
The signs that mean it has become depression
The early signs are about the body and daily habits. The next group is about mood, and it is the group that separates a difficult winter from depression that needs treatment.
Low mood most of the day, nearly every day. Loss of interest in things that used to matter, including hobbies, people, and work. A sense of hopelessness about the winter ever ending. And, for some people, thoughts of not wanting to be here.
Psychiatrists use a specific definition for the seasonal pattern. In plain words, the depression starts and ends in the same season, it has happened at least two years in a row, and it lifts fully in between. The formal criteria are described in the DSM-5-TR and summarized in this clinical review. A psychiatrist will also check that seasonal episodes outnumber any episodes that happened outside the season.
If that last sign applies to you right now, please do not wait for an appointment.
How long it lasts
Untreated, winter pattern seasonal depression tends to run the length of the short days. NIMH reports that symptoms last about four to five months out of the year for most people who have it. That is roughly November through March in Colorado.
Treatment changes that timeline. When light therapy, therapy, or medication begins in the fall, before the worst weeks, many people report a shorter and milder season. That is the main reason this series encourages an evaluation in October rather than a wait-and-see approach in January. Post 4 in this series, on treatment options when seasonal depression keeps coming back, explains what starting early looks like.
Seasonal depression versus other things it gets confused with
Several common conditions share symptoms with seasonal depression, and a good evaluation rules them in or out. Here is how a psychiatrist usually tells them apart.
| Looks like | How it overlaps | How a psychiatrist tells the difference |
|---|---|---|
| Winter fatigue | Tired, less active, more time indoors | Fatigue alone, without mood change, loss of interest, or sleep and appetite change, and it does not build week over week |
| Thyroid problems | Fatigue, weight gain, low mood, feeling cold | A simple blood test. Thyroid symptoms do not follow the calendar and do not lift in spring |
| Vitamin D deficiency | Fatigue, low mood, aches | A blood test. Low vitamin D can occur alongside seasonal depression but does not explain the full pattern on its own |
| Burnout | Exhaustion, cynicism, trouble focusing | Burnout tracks with workload and improves with real time off. Seasonal depression tracks with daylight and does not |
Burnout is common among the people we see, and it can sit on top of a seasonal pattern. If work is the main driver, our burnout page describes how we approach it.
What to do in October if the checklist looks familiar
Start with an evaluation, not a lamp. Light therapy helps many people, but it works best when it is part of a plan built on an accurate picture of what is going on, including the conditions in the table above. A 60-minute intake with a psychiatrist covers your history, the timing of past winters, your sleep and appetite, and any medications you already take. From there, you and your provider decide what the fall plan should be.
While you wait for that appointment, or alongside it, there are practical steps that make the season easier. Post 3 in this series is a winter home checklist with nine things to set up before the days get short. Post 1 explains why seasonal depression shows up in a state as sunny as Colorado. And if this is not your first difficult winter, Post 4 covers what treatment looks like when seasonal depression keeps coming back.
Axis Integrated Mental Health has four clinics in the Denver area and offers telehealth across Colorado. Intake appointments are covered by most insurance, and no referral is needed.
Not sure where to start? Call one of our four Colorado clinics or start with telehealth.
- Aurora: (720) 400-7025
- Denver Tech Center: (720) 400-7025
- Boulder / Louisville: (720) 400-7025
- Westminster: (720) 400-7025
If you are having thoughts of suicide or of not wanting to be here, call or text 988 to reach the 988 Suicide and Crisis Lifeline. It is free, confidential, and open 24 hours a day. If you are in immediate danger, call 911.
