Seasonal Mood Support

Seasonal mood decline is driven by reduced light exposure shifting circadian phase and altering serotonin and melatonin signalling. Bright light therapy has effect sizes comparable to antidepressants in seasonal affective disorder and is first-line treatment. Timing matters more than duration: morning light advances a delayed phase, while evening light can worsen symptoms. Light therapy can trigger mania in bipolar disorder and requires ophthalmic caution with retinal disease or photosensitising medication. Suicidal thoughts require urgent clinical care, not self-management.

1) Use a 10,000 lux light box for 20-30 minutes within an hour of waking, positioned at eye level and off to the side rather than stared into. 2) Start in early autumn, before symptoms build, and continue until spring. 3) Get outdoors in the morning even on overcast days — outdoor light usually exceeds indoor lighting by an order of magnitude. 4) Keep wake time consistent seven days a week to stabilise circadian phase. 5) Correct vitamin D deficiency, though do not expect it to substitute for light. 6) Maintain aerobic exercise, ideally outdoors in daylight. 7) Consider CBT for SAD, which has better relapse prevention than light therapy alone. 8) Seek clinical care for severe symptoms or any suicidal ideation.

• •Morning bright light therapy
• •Outdoor daylight exposure
• •Consistent wake time
• •Regular aerobic exercise
• •Dim evening light
• •Social contact