7 Signs You're Spending Too Much Time Inside & It's Affecting Your Health

We need sunlight to increase our levels of serotonin, the mood-boosting neurotransmitter. Low levels of serotonin are often linked with mood swings, and sometimes depression. "Additionally, when we are inside all day, we are more likely to be sedentary and less social, and this tends to have a negative impact on our mood," IU Health Psychiatrist Dr. Danielle Henderson tells Bustle. "We are less interactive and engaged, which decreases opportunity for activating and reinforcing activities."