While you might attribute this to low moods or tiredness, it could also result from something known as 'emotional contagion'. "You might be absorbing stress that's not even yours," she said in the ...

Emotional contagion can be triggered by nonverbals such as facial expressions as well as by overt conversational or behavioral cues: A smile can spread from one person to another, and someone who ...

As such, the way the contagion spreads needs to be at the center of your plot, not just a random disease affecting a village ...