Seasonal Affective Disorder in Teens: Causes & Signs of SAD in Teens
Waking up in the mornings when it’s dark outside, leaving school or work when the sun is setting, and gloomier weather in general. It’s easy to see why the shifting seasons can have such an effect on our moods.
Seasonal affective disorder (SAD) is a form of depression that is tied to certain times of the year, following the seasonal pattern. While it’s often more predictable than other conditions because of this pattern, this doesn’t make it any easier to live with.
If your teen is showing signs of seasonal depression, they may find certain times of the year significantly difficult to cope with, affecting their physical and mental well-being. Fortunately, there are effective ways to cope with SAD, and a mental health professional can help guide you on these.
This page can also help you better understand seasonal affective disorder in teens, as it covers:
- What seasonal affective disorder is
- The causes of SAD
- How to tell typical teen hormone changes from SAD
- Understanding if you have signs of SAD
- How SAD is treated
- Where to find professional support for SAD
What Is SAD?
Humans have been tying weather and mood together for as long as we’ve been keeping records, and the idea still lingers in the modern day. Think of the countless songs that lyrically focus on rainy days, or the scenes from films and TV where difficult moments unfold under dark clouds and heavy skies. It’s clear we’ve always known there was a link, even if we didn’t have the language to name it.
Seasonal affective disorder only entered the medical world in the 1980s,1 when science finally confirmed what people already sensed. In other words, it confirmed that light can lift us, and its absence can weigh us down.
Although SAD isn’t fully understood yet, researchers agree there are two main types: winter-pattern SAD and summer-pattern SAD.1 We describe the typical symptoms of both below to help you or your teen determine whether you’re struggling to cope with one or the other.
Winter-pattern SAD symptoms:
If you have winter-pattern SAD, you may experience…
- Persistently low feelings
- Tiredness that lingers through the day
- Sleep that lasts longer than usual, but never feeling rested
- Trouble concentrating on schoolwork or staying motivated
- Withdrawal from friends or skipping activities
- Strong cravings for carbs or sweets, sometimes with weight gain
Summer-pattern SAD symptoms:
In contrast to winter-pattern SAD, summer-pattern SAD can cause…
- Heightened irritability or anxiety
- Nights of disrupted sleep or full insomnia
- A noticeable drop in appetite, sometimes leading to weight loss
- A restless or agitated state that feels constant
- Sudden mood swings that strain relationships
What Causes SAD?
SAD rarely comes from just one cause and tends to build when several systems in the body fall out of sync. For teens, this imbalance can be especially tough. With routines already shifting and hormones in constant motion, chemical imbalances often hit harder and feel more overwhelming.
Below, we take a look at some of the potential causes of SAD in teens:
Serotonin Reduction
In the darker months, the protein that clears serotonin away becomes more active, leaving less of it in the brain.2 With this loss comes a heavier emotional load, which is why sadness and low energy often feel more intense in winter. When daylight returns in spring, serotonin activity steadies again, and for many, symptoms begin to ease.
Melatonin Increase
This hormone tells your body when it’s time to rest, and longer nights can mean the body produces more of it.3 For teens, who already need extra sleep and often run on inconsistent schedules, this increase can turn normal tiredness into a constant sense of fatigue. Instead of waking up refreshed, you may find yourself dragging through the day as though your body never quite caught up with rest.
Body Clock Issues
The body’s circadian rhythm, which you may have heard being referred to as your “internal 24-hour clock,” could play its part in SAD too. Teenagers naturally run on a delayed rhythm,4 which is why late nights and lie-ins feel so normal for them. Seasonal changes in light can disrupt this rhythm further, leaving teens awake when they want to sleep and sluggish when they need to focus. When the body clock isn’t lining up with the outside world, it can make every aspect of school and even social life feel like a battle.
Vitamin D Deficiency
The body produces vitamin D through sunlight on the skin, so when daylight shrinks in winter, levels often drop. Vitamin D helps serotonin work properly;5 so low levels have been linked with stronger depressive symptoms. This doesn’t mean that everyone with SAD has low levels of Vitamin D, but for those who do, the lack of it could make the seasonal dip even more intense.
Genetics
Studies of twins and families suggest that SAD runs in bloodlines, with relatives being likely to share the same seasonal patterns.6 For teens, this means family history can shape vulnerability to seasonal depression. For example, if your parent or sibling struggles in the winter months, the same shifts may show up in you, but it’s worth remembering that genetics only sets the stage. Vitamin deficiencies, light, sleep, and daily habits can still influence how SAD plays out.
Hormones or SAD? How to Spot the Difference
As a teen, you may feel low sometimes for no clear reason, or perhaps find yourself getting inexplicably angry with friends or family. These types of issues are common for most teens. In fact, you’ve probably heard family or teachers chalk it up to “hormones.” However, brushing off inconsistently low feelings as “just hormones” isn’t always the answer. Sometimes, something deeper might be going on.
The tricky part is that hormonal changes and seasonal affective disorder can look very similar, making it hard to know which one you’re really dealing with. For this reason, we’ve provided the following table of comparisons to help you see the differences between hormones and SAD more clearly.
Hormones vs SAD Table:
Symptom | Typical Teen Hormonal Changes | Possible SAD Signs |
Mood | Quick shifts tied to stress, conflict, or everyday pressures | Persistent sadness or irritability that follows a seasonal pattern |
Energy | Occasional tiredness, especially during growth spurts or busy weeks | Ongoing fatigue or lethargy in darker months |
Sleep | Later nights and sleeping in | Oversleeping in winter or insomnia during the summer months |
Appetite | Normal increases during growth phases | Strong seasonal cravings in winter (such as for carbs or sugar) or reduced appetite in summer |
Social life | Ups and downs in friendships or moodiness after arguments | Withdrawal from friends and activities when seasons shift |
Duration | Usually short-lived, changing week to week | Lasts for weeks or months, returning around the same time each year |
If you noticed more of your experiences matching the signs on the right-hand side, it could be worth zooming in a little more on how you’re really feeling. Sometimes the patterns of SAD are easy to miss in the middle of trying to figure out school work and everyday stress, but recognizing them is the first step.
In the next section, you’ll find a short self-questionnaire designed to help you check in with yourself and see whether what you’re feeling could be more than just hormones.
SAD Self-Questionnaire: Checking in With Yourself
Self-questionnaires aren’t about giving yourself a diagnosis, and they’re not about putting a label on how you feel. They’re simply a chance to slow down and notice what’s been going on inside.
Sometimes life moves too quickly to think about what’s going on under the surface, so asking yourself a few honest questions can bring some clarity. There’s never any harm in taking a moment to check in.
If you’re concerned about SAD in yourself, you could ask yourself the following questions. Alternatively, if you’re a caregiver who’s concerned about a teen, you could bring them up sensitively during a private moment when there are limited distractions.
SAD Self-Assessment:
- Do my moods seem to dip around the same time every year, almost like clockwork?
- Have I felt stuck in a low or irritable state for weeks, not just a handful of days?
- When the seasons shift, does schoolwork suddenly feel heavier and harder to focus on?
- Do I notice myself sleeping much more than usual in the winter, or hardly at all once summer rolls in?
- Am I drawn to certain foods, especially those high in carbs and sugar, in the colder months, or do I lose my appetite when it’s hot?
- Have I found myself avoiding friends or social activities because I just don’t have the energy or patience?
Answering “yes” to a couple of these questions doesn’t mean anything is wrong with you, and it doesn’t mean you definitely have SAD. However, what it might mean is that your body and mind are giving you signals worth listening to.
If several of these questions resonate, it may be time to reach out to someone you trust. For example, a parent, teacher, or school counselor can talk about what you’ve been going through.
How Is SAD Treated?
Bright Light Therapy (BLT)
BLT is one of the most common treatments for SAD and involves sitting near a special light box that mimics natural sunlight for around 30 minutes a day.7 Research shows it can ease SAD symptoms, with many people noticing improvements within a few weeks. This is the reason it’s one of the front-line forms of treatment used to treat SAD.CBT-SAD
CBT-SAD is a form of CBT that has been crafted specially for those who are dealing with SAD.8 It focuses on challenging negative thoughts that tend to appear when the seasons change, and has been found to provide benefits that last well beyond a single winter or summer.Antidepressants
You may have already heard of antidepressants being used for depression, most often a type called SSRIs. They work well for many people, but with SA, the focus shifts to bupropion,9 a medication that works in a different way than SSRIs. Your therapist may suggest starting bupropion earlier in the year in order to get a “head start” on SAD.Supplements
As we discussed earlier, vitamin D could play a role in SAD. If, after tests, your doctor finds that you are deficient in vitamin D, they may recommend that you start supplementation or add more vitamin D-rich foods to your diet.10 These small changes could make all the difference to symptoms, but it’s important to follow your doctor’s recommendations first before making any changes.How Is Treatment Usually Given for Teens With SAD?
Now that we’ve covered the SAD treatment methods, you might be wondering what type of setting they’re carried out in. For most teens diagnosed with SAD, treatment takes place in an outpatient setting. This means you keep living at home while attending sessions for therapy or light treatment in a dedicated outpatient facility. This flexibility can make it easier to hold onto your normal routines, and for many young people, this level of care is enough to ease symptoms.
Sometimes, though, SAD can feel more severe, and a standard outpatient plan might not give a teen the structure or consistency they need. In these cases, an intensive outpatient program (IOP) may be recommended. An IOP still lets you stay at home and be connected with family, but it also gives you several sessions each week in a clinical setting. This can give you a lot more in the way of time and space to work through challenges.
You may be recommended an IOP if:
- Your symptoms become so persistent that schoolwork or relationships feel almost impossible to manage
- You’ve already tried different treatment methods, but haven’t noticed much improvement
- The depression tied to SAD deepens to the point where motivation disappears, and everyday life feels unmanageable
- Each year, the seasonal pattern seems stronger, with relapses hitting harder than before
- Another mental health condition, like anxiety or eating disorders, complicates what’s happening during the season
If an IOP recommendation is made, try to think of it as a positive: you’re getting the correct help you need, rather than being lumped under a one-size-fits-all hat. But we get it – it can still be intimidating. For this reason, in the next section, we look at exactly what to expect in an IOP like the ones provided by Mission Prep
Mission Prep: Support for Teens With SAD
If shorter days have left you feeling drained or unlike yourself, it may be a sign of something deeper than the season. Plus, if you’re a parent noticing these shifts in your teen, you may feel concerned and overwhelmed about the right steps to take. Either way, support is available.
At Mission Prep, we help teens and families navigate the challenges of SAD. Our therapy options include CBT and DBT to help manage difficult thoughts and emotions, while family and group sessions can strengthen connection and understanding. For those who need more structure, our inpatient program offers time away from daily pressures to reset in a safe and supportive environment.
Whether you’re a teen struggling through the winter months or a parent searching for answers, you don’t have to carry this on your own. Reach out to Mission Prep today and take the first step toward restoring balance and stability for your family.
References
- Munir, S., & Abbas, M. (2022). Seasonal depressive disorder. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK568745/
- Melrose, S. (2015). Seasonal affective disorder: An overview of assessment and treatment approaches. Depression Research and Treatment, 2015(1), 1–6. https://doi.org/10.1155/2015/178564
- Xu, X., Liu, X., Ma, S., Xu, Y., Xu, Y., Guo, X., & Li, D. (2018). Association of melatonin production with seasonal changes, low temperature, and immuno-responses in hamsters. Molecules, 23(3), 703. https://doi.org/10.3390/molecules23030703
- Hagenauer, M. H., Perryman, J. I., Lee, T. M., & Carskadon, M. A. (2009). Adolescent changes in the homeostatic and circadian regulation of sleep. Developmental Neuroscience, 31(4), 276–284. https://doi.org/10.1159/000216538
- Patrick, R. P., & Ames, B. N. (2015). Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: Relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior. The FASEB Journal, 29(6), 2207–2222. https://doi.org/10.1096/fj.14-268342
- Sher, L., Goldman, D., Ozaki, N., & Rosenthal, N. E. (1999). The role of genetic factors in the etiology of seasonal affective disorder and seasonality. Journal of Affective Disorders, 53(3), 203–210. https://doi.org/10.1016/s0165-0327(98)00194-3
- Campbell, P. D., Miller, A. M., & Woesner, M. E. (2017). Bright light therapy: Seasonal affective disorder and beyond. The Einstein Journal of Biology and Medicine, 32, E13–E25. https://pmc.ncbi.nlm.nih.gov/articles/PMC6746555/
- National Center for Complementary and Integrative Health. (2019, January). Seasonal affective disorder and complementary health approaches: What the science says. https://www.nccih.nih.gov/health/providers/digest/seasonal-affective-disorder-and-complementary-health-approaches-science
- Gartlehner, G., Nussbaumer-Streit, B., Gaynes, B. N., Forneris, C. A., Morgan, L. C., Greenblatt, A., Wipplinger, J., Lux, L. J., Van Noord, M. G., & Winkler, D. (2019). Second-generation antidepressants for preventing seasonal affective disorder in adults. The Cochrane Database of Systematic Reviews, 2019(3), CD011268. https://doi.org/10.1002/14651858.CD011268.pub3
- Jahan-Mihan, A., Stevens, P., Medero-Alfonso, S., Brace, G., Overby, L. K., Berg, K., & Labyak, C. (2024). The role of water-soluble vitamins and vitamin D in prevention and treatment of depression and seasonal affective disorder in adults. Nutrients, 16(12), 1902. https://doi.org/10.3390/nu16121902
