Your body runs on clocks.
Some are daily (your 24-hour circadian rhythm) while others are seasonal, shaped by changes in daylight length, temperature, and routine.
Those clocks tug on neurotransmitters, hormones, sleep timing, immune activity, and even how quickly your brain’s alarm system fires.
That’s why the texture of anxiety can change by month or light level, not just by stress load.
In this piece, we’ll explore the seasons of your nervous system, and how you can identify these patterns and use them to your advantage. For a deeper dive, you can listen to the latest episode of Mental Health Bites here on Substack or on Apple Podcasts. You can also find more short clips and helpful tips at my YouTube channel.
Let’s jump in!
Why Your Nervous System Has Seasons
In healthy humans, the brain’s serotonin transporter (the protein that clears serotonin from synapses) tends to be higher in fall and winter. This corresponds to lower serotonin availability in the brain.
Many people don’t feel “sad” so much as “keyed up,” more jittery, or more prone to rumination when daylight drops; that can be a serotonin story as much as a mood story.
At the same time, melatonin rhythms shift later in winter by roughly half an hour on average, this adds grogginess in the morning and a “wired-but-tired” feeling at night. If your work and parenting schedule doesn’t budge, that small delay can magnify anxiety simply because your body and calendar are moving out of sync.
Stress Hormones Have Seasons Too
Large datasets suggest measurable seasonal variation in cortisol. Though not every study agrees on the exact timing, many show higher levels in cooler, darker months.
What matters clinically is that your baseline arousal can drift with the season even if nothing “bad” is happening, which makes everyday bumps feel larger.
One more piece to remember is that your immune system cycles across the year, with winter-weighted increases in inflammatory signaling for many people. Because inflammation can heighten threat sensitivity and interoceptive “noise,” winter tends to be a period when somatic anxiety (heart-pounding, tight chest, air hunger) shows up more readily.
Practical Tip: Map Your Anxiety Seasons
When you put all this together, you get the central idea: Your anxiety isn’t random and it isn’t a personal failing;iIt’s often a mismatch problem, your biology shifting with the season while your routines stay fixed.
The fix is timing the right supports and challenges to the right season, much like athletes periodize training for peak performance and recovery. I suggest you think of it as though you are building your own Anxiety Season Map. To do this, you don’t need an app or a graph. All you need is a notes app or paper.
* Take a 60-second daily snapshot. Every evening, jot down for quick items: “Anxiety today: __/10.” // “Sleep: ____ hours; bedtime/waketime.” // “Daylight outside: about __ minutes.” // “Notables: work load high/medium/low; allergies yes/no; hormones or cycle notes if relevant.” (Keep this under a minute so you’ll actually do it.)
* Do a 5-minute weekly review. Once a week, skim your notes and answer three questions out loud: When did anxiety tick up? What changed in light, sleep, or schedule before that? What helped on better days? Circle any repeating duo, like “low daylight + later bedtime = higher anxiety.”
* Mark your “yellow” and “red” months. Looking back 4–8 weeks, or using your memory for last year, label months as: Green (baseline resilience), Yellow (you trend a little more anxious), Red (you reliably spike). If you’re unsure, pick the two months you suspect are hardest and treat them as red for a trial season.
* Pre-load supports two weeks early. Create a two-week runway before each yellow/red month. Choose two of these guardrails and commit. Morning light: get outside within an hour of waking for 10–20 minutes, eyes in daylight (no sunglasses if comfortable). // Sleep guardrails: fixed wake time (±30 min), dim lights/screens an hour before bed. // Movement minimum: 20 minutes of any movement daily. // Social anchor: schedule two supportive check-ins per week. // Exposure “maintenance”: 10 minutes, 3 days a week, of a mild exposure relevant to your anxiety (e.g., a short drive on a route that makes you uneasy; sending one imperfect email). // Say it like a rule: “Starting September 15th, morning light + fixed wake time for 14 days.”
* Time your challenges to your season. Use Green months for bigger pushes (harder exposures, presentations, crowded drives) because your baseline is steadier. In Yellow, keep momentum with small reps and more recovery. In Red, simplify: protect sleep, keep morning light, and downshift exposures to maintenance so you don’t disappear from the ladder. If an unexpected spike hits, use a 90-second reset: lengthen your exhale, do a quick 5-4-3-2-1 grounding, and then take the smallest action toward your value—send the message, step outside, start the drive timer. The goal isn’t perfect calm; it’s staying in motion in a way that respects your biology.
* Close the loop every quarter. Glance at your notes, update your color map, and adjust the two-week runways. In one season you’ll know your pattern; in two, you’ll be steering into it.
When you honor the clocks inside you (light, sleep, hormones, immune signals) you stop fighting the tide and start surfing it.
If this helps, I encourage you to subscribe, leave a review, and share it with someone who gets “seasonal jitters.” For extra tools and the Anxiety Season Map checklist, head to my Substack at drjudyho.substack.com.
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About me:
Dr. Judy Ho, Ph. D., ABPP, ABPdN is a triple board certified and licensed Clinical and Forensic Neuropsychologist, a tenured Associate Professor at Pepperdine University, television and podcast host, and author of Stop Self-Sabotage. An avid researcher and a two-time recipient of the National Institute of Mental Health Services Research Award, Dr. Judy maintains a private practice where she specializes in comprehensive neuropsychological evaluations and expert witness work. She is often called on by the media as an expert psychologist and is also a sought after public speaker for universities, businesses, and organizations.
Dr. Judy received her bachelor's degrees in Psychology and Business Administration from UC Berkeley, and her masters and doctorate from SDSU/UCSD Joint Doctoral Program in Clinical Psychology. She completed a National Institute of Mental Health sponsored fellowship at UCLA's Semel Institute.
