Major Depressive Disorder (MDD) is a serious mental health condition. Let's think of it like a "mood flu" that lasts longer and hits harder. DSM-5, our "disease dictionary", lists down 9 common symptoms of MDD:

• Depressed mood: Feeling blue or super down? It's like a cloud of sadness constantly following you.

• Diminished interest or pleasure: Ever felt like your favorite game or show suddenly isn't fun anymore? That's this symptom talking.

• Significant weight change: Losing or gaining weight like a yo-yo without trying? We're talking 5% of body mass in a month!

• Insomnia or hypersomnia: Either partying with insomnia or on a non-stop sleep marathon with hypersomnia.

• Psychomotor agitation or retardation: Feeling like you've had 10 cups of coffee (agitation) or like you're moving in slow motion (retardation).

• Fatigue: It's like carrying a backpack full of bricks all day, every day.

• Feelings of worthlessness or guilt: It's like that nagging voice telling you that you're not good enough or it's always your fault.

• Diminished ability to think or concentrate: It's like you're reading this note for the 10th time and still not getting it.

• Recurrent suicidal thoughts: If the cloud of sadness gets too heavy, it sometimes whispers about ending it all. That's serious and help should be sought immediately.

MDD isn't something that's diagnosed on a whim. Imagine a checklist, and the DSM-5 says we need:

• 5 or more symptoms for at least two weeks
• A change from your usual self
• At least one symptom is either a depressed mood or loss of interest or pleasure
• The symptoms cause distress or hinder daily activities
• Other conditions and disorders have been ruled out