☔️Take Care of Your Autonomic Nervous System During the Change of Seasons🌧️

September has arrived, but in Tokyo, we have been experiencing frequent rainy days.

Recently, we have seen more patients at our clinic who say:

• “I’ve been feeling unusually down lately.”
• “I feel tired and heavy even after sleeping.”
• “I have no motivation.”
• “I feel more anxious or irritable than usual.”
• “My headaches or muscle tension have become worse.”
• “I just don’t feel like myself.”

Many people notice that their mood and physical condition seem to change when the weather changes.

While rainy weather does not directly cause depression, changes in weather, temperature, atmospheric pressure, sunlight, and daily routines can affect both our physical and emotional well-being.

Can rainy weather affect your mood?

Research has suggested that weather and environmental conditions may be associated with depressive symptoms.

For example, a study of more than 8,000 adults aged 50 and older examined the relationship between weather conditions and depressive symptoms. The researchers found that higher levels of rainfall were associated with slightly higher levels of depressive symptoms. Longer periods of sunlight were also associated with fewer depressive symptoms.

However, it is important to emphasize that this does not mean that rainy weather causes depression. Many factors—including physical health, lifestyle, social circumstances, sleep, and individual vulnerability—can affect mood.

Still, these findings suggest that environmental changes may play a role in how some people feel.
(O’Hare et al., 2016)

What does the autonomic nervous system have to do with it?

The autonomic nervous system helps regulate many functions that happen automatically in our bodies, including heart rate, blood pressure, body temperature, digestion, and sleep.

Our autonomic nervous system also interacts closely with our emotional state.

Research examining heart rate variability (HRV), a commonly used indicator of autonomic nervous system activity, has found associations between autonomic regulation and emotional states. In particular, reduced parasympathetic activity has been associated with negative emotional states in some studies.
(Gullett et al., 2023)

This is one reason why stress can affect the body, and why physical discomfort can also affect our mood.

For example:

Stress → disrupted sleep and changes in autonomic regulation → physical fatigue or discomfort → lower mood

The relationship between the mind and body is complex and works in both directions.

Autumn also brings changes in daylight

As we move from summer into autumn and winter, the amount of daylight gradually decreases.

Changes in daylight exposure and circadian rhythms have been studied extensively in relation to Seasonal Affective Disorder (SAD).

SAD is a form of depression in which depressive symptoms tend to occur during a particular season, most commonly beginning in autumn or winter and improving in spring.

Light exposure plays an important role in regulating our circadian rhythm, or internal biological clock.

However, not everyone experiences seasonal changes in mood.

A systematic review of 41 studies found that the evidence for a general seasonal pattern of depression is mixed. Some studies have reported seasonal variation, while others have not. In other words, it would be too simplistic to say that everyone becomes depressed during the winter months.
(Øverland et al., 2019)

What is important is to pay attention to your own changes in mood, sleep, energy, and daily functioning.

How can you take care of yourself during the change of seasons?

You do not need to make dramatic changes to your lifestyle.

Small, consistent habits can be helpful.

1. Wake up at around the same time every day

Try to maintain a relatively consistent wake-up time, even on weekends.

A regular sleep-wake schedule can help support your circadian rhythm.

2. Get some morning light

Even on rainy days, open the curtains and spend some time in a bright environment after waking up.

If the weather permits, going outside for a short walk can be helpful.

Light exposure in the morning is particularly important for regulating the body’s internal clock.

For people with Seasonal Affective Disorder, light therapy is also an established treatment option, although it should be used appropriately and, particularly for people with certain medical or psychiatric conditions, discussed with a healthcare professional.

3. Get some gentle exercise

You do not have to start an intense exercise program.

A short walk, stretching, yoga, or light exercise may be enough to get started.

Even 10–20 minutes of movement can be a good first step.

The goal is not perfection. The goal is consistency.

4. Prioritize sleep

Changes in weather and daily routines can sometimes affect sleep.

Some people feel unusually sleepy, while others have difficulty falling asleep or wake frequently during the night.

Rather than becoming anxious about getting “perfect” sleep, start by keeping your wake-up time relatively consistent and creating a relaxing routine before bedtime.

5. Give yourself permission to slow down

When you are already feeling mentally or physically exhausted, pushing yourself harder is not always the answer.

On difficult days, it is perfectly reasonable to think:

“Today, doing the essentials is enough.”

Reading a book, listening to music, taking a warm bath, having a cup of tea, or simply allowing yourself some quiet time can all be part of taking care of your mental health.

Don’t assume that everything is “just the weather”

Feeling a little less energetic on a rainy day is not necessarily a sign of a mental health disorder.

However, if your symptoms continue or begin to interfere with your daily life, it is important not to simply blame the weather or the change of seasons.

You may want to consider talking with a healthcare professional if you notice:

• Persistent low mood
• Loss of interest or pleasure in things you normally enjoy
• Difficulty concentrating
• Persistent anxiety or excessive worry
• Difficulty sleeping or sleeping much more than usual
• Significant changes in appetite
• Persistent fatigue or lack of energy
• Difficulty going to work or performing daily activities
• Losing interest in social activities or avoiding other people
• Feeling that you are no longer functioning as you normally do

Seasonal and weather-related changes can affect people differently, and there is no single explanation for why someone may feel worse at a particular time of year.

Rather than trying to identify one cause, it is important to look at the whole picture—including sleep, stress, physical health, lifestyle, and emotional well-being.

Your mind and body are connected

September can be a challenging time of year.

The fatigue accumulated during the summer may still be present, while temperatures, humidity, daylight hours, and daily routines begin to change.

If you find yourself thinking:

“I don’t feel quite right.”
“I feel unusually tired.”
“I can’t seem to lift my mood.”

take it as an opportunity to pause and check in with yourself.

Pay attention to your sleep, daily routine, activity level, stress, and mood.

And if these symptoms continue, you don’t have to simply wait for the season to change.

Taking care of your mental health is just as important as taking care of your physical health.

At Azabu Juban Clinic, we provide consultations for depression, anxiety, insomnia, stress-related symptoms, and other mental and physical health concerns.

If you are struggling or simply feel that something has changed, please feel free to consult with us.

---

References

1. O’Hare C, O’Sullivan V, Flood S, Kenny RA. Seasonal and meteorological associations with depressive symptoms in older adults: A geo-epidemiological study. Journal of Affective Disorders. 2016;191:172–179. doi:10.1016/j.jad.2015.11.029.
2. Øverland S, et al. Seasonality and symptoms of depression: A systematic review of the literature. Epidemiology and Psychiatric Sciences. 2019;29:e31. doi:10.1017/S2045796019000209.
3. Gullett N, Zajkowska Z, Walsh A, Harper R, Mondelli V. Heart rate variability (HRV) as a way to understand associations between the autonomic nervous system (ANS) and affective states: A critical review of the literature. International Journal of Psychophysiology. 2023;192:35–42. doi:10.1016/j.ijpsycho.2023.08.001.
4. Rothenberg M, et al. Lifestyle modification as intervention for seasonal affective disorder: A systematic review. Journal of Psychiatric Research. 2024;174:240–249.
5. Wan Y, Ding J, Fan M, Huang H. Effectiveness of visible light for seasonal affective disorder: A systematic review and network meta-analysis. Medicine (Baltimore). 2025;104(27):e43107.