Factors affecting sleep quality and caffeine responses

Several factors can prevent the body from sleeping despite feeling tired. Key contributors include disruptions to the circadian rhythm, improper napping habits, anxiety, and depression. Research suggests that long or late afternoon naps can decrease sleep quality at night. Additionally, anxiety can increase alertness, while up to 90% of individuals with depression experience sleep disturbances such as insomnia or restless leg syndrome.

Caffeine consumption significantly impacts sleep quality. The half-life of caffeine averages five hours, and consuming even 200mg up to 16 hours before bed can interfere with rest. Blue light from electronic screens also suppresses melatonin production, making it harder to fall asleep.

In some cases, caffeine may cause a paradoxical feeling of drowsiness. This can occur due to excessive doses affecting adenosine receptors, genetic variations in how the body processes caffeine, hormonal imbalances affecting adrenaline production, or liver dysfunction that impacts how substances are filtered and delivered to the brain.