Issue 407: Feeling Blue in Fall and Winter?

Overview 1 ⟫ What is seasonal depression?

Seasonal depression, also known as Seasonal Affective Disorder (SAD) or seasonal mood disorder, refers to recurring disturbances in mood and behavior that appear during a particular season or time of year. It most commonly occurs in autumn and winter, though a small number of people experience symptoms in the summer.

The prevalence of SAD varies by latitude, typically ranging from about 1.5–10%. In higher-latitude regions, the rate may reach 10.7%.

Overview 2 ⟫ What causes seasonal depression?

Most current studies focus on fall–winter SAD. While the exact cause remains unclear, it is believed to be related to reduced daylight hours and changes in hormones.

As sunlight decreases and temperatures drop, serotonin levels and overall energy for physical activity may decline, potentially triggering depressive symptoms in susceptible individuals.

Key factors include:

1 ⟫ Increased melatonin

Melatonin regulates the body’s sleep–wake cycle and is usually secreted after dark to help us sleep. Research suggests that reduced daylight in fall and winter can raise melatonin levels. Although this may make it easier to fall asleep, sleep quality may worsen, leading to drowsiness, fatigue, and mood instability.

2 ⟫ Decreased serotonin

Serotonin plays an important role in regulating mood and sleep. With shorter daylight hours, the mechanisms that maintain serotonin activity may be disrupted, resulting in lower levels and increased feelings of depression, sadness, or anxiety.

Overview 3 ⟫ What are the symptoms of seasonal depression?

• Persistent low or unstable mood; irritability or frequent crying
• Strong cravings for carbohydrates, especially sweets, sometimes leading to overeating and weight gain
• Constant fatigue, sleepiness, difficulty concentrating
• Poor sleep quality or trouble falling asleep
• Social withdrawal and reduced interest in social activities

Overview 4 ⟫ Six dietary principles to help improve mood

1 ⟫ Choose whole grains

Adequate carbohydrates help synthesize serotonin. Whole grains and unrefined staples also provide B vitamins, selenium, and zinc, nutrients linked to mood improvement and anxiety reduction.

Good options include pumpkin, brown rice, corn, sweet potatoes, and chestnuts. Reduce refined sugar intake to avoid sharp blood sugar swings that can destabilize mood.

2 ⟫ Five servings of fruits and vegetables daily

Studies show higher produce intake is associated with a lower risk of depression, with citrus fruits and dark green vegetables being especially beneficial.

Eating enough fruits and vegetables also supports gut health, provides antioxidants, and helps fight inflammation, all of which contribute to emotional well-being.

3 ⟫ Eat fish every week

A lack of omega-3 fatty acids can affect the transmission of mood-related neurotransmitters such as tryptophan and dopamine. Research has found that women who eat fish at least twice per week have a 25% lower risk of depression compared with those who eat fish less often.

Choose mackerel, saury, or salmon. Vegetarians can obtain omega-3s from olive oil, flaxseed oil, walnuts, and avocados.

4 ⟫ Get enough vitamin D

Vitamin D is involved in immune and nervous system regulation. Insufficient intake may increase the risk of depression. Try to get sunlight exposure in the morning or at noon to stimulate vitamin D production.

Dietary sources include egg yolks, sun-dried mushrooms, salmon, eel, and fortified milk.

5 ⟫ Cut back on junk food

Studies indicate that ultra-processed foods high in saturated fat—such as sweets, soda, and fast food—may increase depression risk. Diets rich in fruits, vegetables, whole grains, nuts, olive oil, fish, and legumes are associated with lower risk.

6 ⟫ Maintain a healthy weight

Many studies show a correlation between obesity and depression. Regular exercise is recommended, aiming to keep BMI between 18.5 and 24.

Conclusion ⟫

Mood changes during seasonal transitions are a common challenge for many people each year. Through proper nutrition, regular physical activity, and adequate sleep, it is possible to ease emotional lows. When needed, remember to seek professional medical support to effectively maintain both mental and physical well-being.

Source: Learn Eating

https://views.learneating.com/clinical-nutrition/seasonal-affective-disorder-diet/