Our internal body clock helps regulate sleep, alertness and mood, following a roughly 24-hour cycle influenced by light and darkness. vetre/Shutterstock Ever wondered why a bad night’s sleep can leave you irritable, anxious or sad? Poor sleep affects our emotions, but its timing also plays a role. Our circadian…

A new study identifies circadian depression, suggesting that disrupted sleep patterns and body clocks may influence depression symptoms and antidepressant response.

The body's internal clock influences when people feel sleepy and alert. Researchers are investigating whether differences in these rhythms could help explain responses to antidepressants. Photoroyalty/Shutterstock A person with depression might sleep much longer than usual and still wake feeling exhausted. Later that…