Sleep and mood are tightly connected to one another. Every single one of us is painfully aware of this link. If you got bad sleep the night before, you’re probably going to be a little more irritable, right? You’ll also be more easily frustrated by the petty obstacles that routinely confront us throughout the day, like rush hour traffic or uncooperative computers. In general, you’re just not the best version of yourself. We’ve all been there. Importantly, this relationship is bidirectional. Disruptions in sleep can produce alterations in emotional functioning, and our mood can also influence our sleep patterns. If you’re angry or super stressed out, you’re probably going to have a harder time falling asleep and staying asleep. Research in controlled laboratory settings bears this out. Subjects whose sleep is partially restricted for one week experience greater stress, anger, and mental exhaustion. And these deleterious effects on mood seem to get worse over time, as the conse