What is seasonal affective disorder (SAD)?

Seasonal affective disorder, or SAD, is a type of depression tied to the changing seasons. For most people it arrives as the days get shorter and lifts as they lengthen again. It is a recognized clinical condition, not simply a preference for summer.

What SAD is and when it happens

SAD is not a separate illness so much as a pattern a depressive disorder can follow. Clinicians describe it as a seasonal specifier: the same depression, with timing as its defining feature. The common form, winter-pattern SAD, begins in late fall or early winter and eases in spring. A less common summer-pattern form runs the other way and tends to look different, with agitation, poor appetite, and insomnia rather than heaviness and oversleeping.

The leading explanation for the winter pattern involves circadian rhythm. Light entering the eye in the morning is the main signal that sets the body clock, and when sunrise moves toward eight and sunset toward four, that signal weakens and shifts later. Sleep timing, alertness, and mood regulation all track that clock. It is also why a Buffalo winter, with its long overcast stretches, is harder on this than a lower-latitude one.

What it actually looks like

Winter-pattern SAD often runs opposite to the classic picture of depression. Instead of early waking and appetite loss, people usually sleep more and eat more, with carbohydrate cravings and weight gain over the season.

In daily life it looks less like sadness than like a slow drain. Getting out of bed takes an hour longer than it did in September. Work is doable but everything requires visible effort. Plans get cancelled through November and December, not because you dislike anyone but because leaving the apartment costs more than the evening seems worth. Things you enjoyed in July feel like obligations.

To fit the seasonal pattern, this recurs at roughly the same time of year across at least two years, lifts in spring, and interferes with work, relationships, or daily functioning rather than being a passing dip.

The part people miss: it is predictable

The distinguishing feature of SAD is also its most useful one. Unlike most depression, you know roughly when it is coming, which makes it one of the few presentations where the work can start before the symptoms do. People who have been through several cycles often know their onset window fairly precisely, and setting up structure, treatment, and social commitments in September rather than December changes what the season looks like. Waiting until you are already flat means trying to build routines with the least energy you will have all year.

How SAD differs from an ordinary winter low

Plenty of people feel flatter or slower in winter. That is common, mild, and does not stop the week from happening.

SAD is different in intensity and impact: the symptoms last most of the day for weeks, and they disrupt functioning. The practical questions are whether you are missing work or obligations, whether other people have noticed, whether it recurs on schedule, and whether it lifts in spring. If the answer to most of those is yes, this is seasonal depression rather than a slump. The overlap with situational low mood is one reason it is sometimes confused with an adjustment reaction, which is tied to a life event rather than a calendar.

Light therapy, described accurately

Light therapy is one of the standard first-line treatments for winter-pattern SAD and has been studied for decades. The general approach is a light box used daily, most often in the morning, positioned near where you sit rather than looked at directly. Boxes designed for this purpose filter ultraviolet light.

We are a therapy practice and not a prescribing one, so we do not set intensity, duration, or timing for anyone. Those details matter, and getting them wrong can produce headaches, eye strain, or a shifted sleep schedule. They belong with a physician or psychiatric prescriber, particularly if you have an eye condition, take a medication that increases light sensitivity, or have any history of bipolar disorder. Response varies between people.

What therapy adds

Cognitive behavioral therapy adapted for seasonal depression targets two things light does not.

The first is behavior. Winter depression produces withdrawal, and withdrawal produces less of everything that ordinarily sustains mood. The work involves scheduling activity deliberately, at a level you can do at your worst rather than your best, and protecting the social contact that quietly disappears when it gets dark early.

The second is the thinking that hardens over a season: this always happens, nothing helps, no point starting anything until March. Those thoughts are convincing in February and they drive the exact withdrawal that deepens the pattern.

This work also aims at next winter as well as this one, since skills learned in one season carry over. Our seasonal affective disorder therapy builds around both, and monthly reviews with standardized measures let you and your clinician see the seasonal curve in data rather than impression.

Starting before the light goes

The best time to make a plan for winter is while it still feels unnecessary. If you have been through this cycle and can name the month it usually starts, a few sessions in late summer are worth more than an emergency appointment in January.

We work with adults 18 and over in Jamaica, Queens, in Buffalo, and by telehealth, which matters in a condition where getting out the door in February is part of the problem. Book at choose your therapist or call (646) 493-4007.

If you are having thoughts of suicide, call or text 988 for immediate support. MindView is not a crisis service.