Many people often feel depressed, tired or irritable when it rains. This phenomenon is called seasonal affective disorder (SAD), which is a type of depression related to changes in seasons.

According to scientists, there are several factors that can cause SAD, such as the lack of sunlight, the drop in temperature, the change in circadian rhythm and the increase in melatonin.

Sunlight is important for the production of serotonin, a neurotransmitter that regulates mood, appetite and sleep. When there is less sunlight, the level of serotonin decreases, leading to lower mood and energy.

Temperature also affects mood, as cold weather can make people feel more sluggish and less motivated. Cold weather can also trigger inflammation, which is linked to depression and anxiety.

Circadian rhythm is the body’s internal clock that tells us when to wake up and when to sleep. When the days are shorter and darker, the circadian rhythm can be disrupted, causing insomnia or oversleeping, which can affect mood and cognitive function.

Melatonin is a hormone that helps us sleep at night. When it is dark, the pineal gland in the brain produces more melatonin, making us feel sleepy. However, too much melatonin can also cause depression, as it reduces dopamine, another neurotransmitter that influences mood and motivation.

To cope with SAD, scientists suggest some tips, such as getting more exposure to natural light, exercising regularly, eating healthy foods, socializing with friends and family, and seeking professional help if needed.