SAD can affect anyone, but certain groups are more vulnerable, including women, younger adults, and individuals with a history of depression or bipolar disorder. In California, the condition is exacerbated by geographic factors like prolonged fog in the Central Valley and extended rainy seasons in Northern California. Symptoms can interfere with daily life, work, and relationships, making early diagnosis and treatment crucial. Without intervention, the condition can persist for months, significantly impacting mental health and overall well-being (Lean Medical, 2026).