If you’ve ever struggled with depression, or loved someone who has, you know how heavy it can feel. People on the outside often think it’s just sadness, or worse, that it’s weakness or laziness. But depression is not a character flaw. It’s biology. And understanding that difference can change everything about how you approach healing.

What’s Really Happening in the Brain?

Depression is linked to changes in brain chemistry: specifically, the neurotransmitters serotonin, dopamine, and norepinephrine. These brain chemicals do so much more than regulate mood:

• Serotonin helps regulate mood, sleep, appetite, and emotional processing. Low levels often feel like irritability, anxiety, or that heavy, gray weight many people describe.
• Dopamine drives motivation, focus, and pleasure. When dopamine is low, life feels flat. You may go through the motions, but nothing feels rewarding.
• Norepinephrine supports alertness, concentration, and stress response. When it’s low, you feel foggy, tired, and unable to think clearly.

When these systems are disrupted, it can show up as fatigue, brain fog, appetite or sleep changes, lack of motivation, and even an inability to feel joy. That’s why depression often feels like swimming with weights tied to your body. It’s not willpower—it’s chemistry.

High-Functioning Depression: Same Biology, Different Mask

Some people with depression are able to keep going to work, taking care of their families, and keeping up with responsibilities. From the outside, they may look fine. But inside, they’re often numb, exhausted, and barely holding it together.

This is what we call high-functioning depression. The biology is the same as someone who can’t get out of bed. The neurotransmitter levels don’t change just because you push yourself through the motions. That’s why it’s so important to understand: you’re not “less depressed” if you’re functioning, and you’re not “more depressed” if you’re not.

You are not lazy. You are not weak. You are sick. And sick people can heal.

The Revised Monoamine Hypothesis

One of the major frameworks for understanding depression is called the Revised Monoamine Hypothesis. It suggests that deficiencies in serotonin, dopamine, or norepinephrine disrupt emotional balance. This explains why:

• Some people struggle most with motivation and pleasure (dopamine).
• Others feel anxious, irritable, or emotionally flat (serotonin).
• Others are weighed down by fatigue and brain fog (norepinephrine).

This is also why treatments don’t work the same for everyone, because depression can look different depending on which systems are most affected.

If you’ve seen my video, you know I use a graph to show mild, moderate, and severe depression, and why some treatments help certain people more than others.

It’s not the whole story, though. Newer research shows that stress, inflammation, and neuroplasticity (the brain’s ability to rewire itself) also play major roles. We’ll be diving into these more advanced ideas in my video course.

The Hope: Your Brain Can Heal

Here’s the part I don’t want you to miss: your brain is not broken. It’s adapting. And it can heal.

Think about it—if you scratch your car, it doesn’t fix itself. But if you scratch your skin, your body heals it automatically. That’s remarkable.

The brain works the same way. Even people with strokes or brain injuries, where actual tissue has been damaged, can sometimes regain function. That’s because the brain builds new neurons and connections, a process called neuroplasticity. It’s why some people relearn how to walk, speak, or even smell after COVID.

And here’s the good news: in depression, there isn’t permanent injury. Unless you’ve had a traumatic brain injury, nothing is lost. Your brain can rebalance neurotransmitters, form new pathways, and adapt. Your body is not working against you; it’s working with you.

Healing Isn’t Linear

One last truth: healing from depression is not a straight line. You’ll have good days and setbacks. People around you may celebrate your progress but get frustrated if you slip backward. Sometimes even therapists misinterpret setbacks as failure.

But setbacks don’t mean failure. They mean you’re human. The goal isn’t perfection, it’s to increase the number of good days over time, with grace for the hard ones.

So please: be kind to yourself. You’re not broken. You’re healing.

Want to Go Deeper?

Over the last ten years, I’ve counseled hundreds of patients across thousands of visits about depression. I’ve also lived with it myself since I was a teenager. I’ve taken everything I’ve learned: the medical science, the practical strategies, and the small daily tips that really make a difference, and created a video course on depression.

It’s all the guidance I wish I had when I was first struggling.