Light Therapy: A treatment for SAD that involves exposure to artificial light. It's like using a sun lamp when there's no sunlight available.
Melatonin: A hormone that plays a role in sleep patterns. Its levels are affected by light exposure; it’s akin to your body’s natural alarm clock responding to sunrise or sunset.
Circadian Rhythm Disorders: These are disruptions in a person's circadian rhythm - a name given to the "internal body clock" that regulates the 24-hour cycle of biological processes. Imagine if your internal clock was set differently from everyone else’s – you’d be sleepy when others are awake, which can be quite disruptive.