Depression and its variants are known for causing many negative emotional effects like persistent sad moods, feelings of helplessness, and apathy.

But depression symptoms also have roots that tie into our underlying biology, like our brains and hearts.

Here, we’ll break down some of these connections, so that we can get some answers to the questions: ‘Why do I feel this way?’ ‘Why am I depressed?’ and more importantly, ‘What causes depression?’

Read on to understand how depression affects both our brains and bodies.

The Brain

It’s best to start at the control center of our bodies, the brain! While there’s so much to talk about with regard to the brain and mental disorders, we’ll break it down to some of the more important factors in the biology of depression.


Neurotransmitters are simply chemicals in in the brain that have different jobs and roles.

If the brain is like a corporate office, neurotransmitters would be the different teams with different responsibilities in the company. Below are some of the main neurotransmitters researchers have pinpointed that play a role in the symptoms of depression.


A transmitter that helps with desire, learning, memory, appetite, body temperature, and much more. Individuals with depression typically have a shortage of serotonin compared to the average person. This can relate to a number of factors — even ones as simple as not getting enough sunlight.


This transmitter helps with reward responses, movement, and emotional responses. You know that rush you feel when you finish a marathon or complete a difficult level in a video game? That’s dopamine. Depressed individuals tend to have lower levels of dopamine on average.


This neurotransmitter is related to attention, sleep, and arousal among other roles. People with depression tend to have lower levels of norepinephrine on average, but too much of it can actually contribute to anxiety and other unpleasant effects.

GIF illustrating the balance of neurotransmitters.

What Does This All Mean For The Body?

Depression is linked to imbalances in certain neurotransmitters, not having enough of something or having too much of it.

We don’t always know what causes their levels to vary, but these imbalances can explain some concrete symptoms like low mood or inability to feel pleasure.

It’s a common misconception that depression is something you can simply ‘get over,’ but as we can see, that isn’t the case! Depression has biological roots that are still being researched every day, and we know depression also impacts the following body systems:

Circadian Rhythm and Sleep

Another factor to take into account is how depression affects circadian rhythm, which is the internal clock in a specific part of the brain that helps us with sleep.

Depression distorts our internal clock and can cause some individuals to have a harder time sleeping, or make some individuals sleep longer than average. It’s similar to the feeling we get when we experience jet lag, but it’s inescapable.

The Heart

Depression has a clear relationship with the cardiovascular system in the body. For example, individuals with depression are about two to five times more likely to have heart issues, whether it’s in the form of heart attacks, strokes, or developing serious heart diseases in the future.

Why The Heart?

So we can see that depression is a risk factor for heart problems, but why is this the case? The answer may go back to neurotransmitters.

Depression triggers chemical imbalances in our bodies that can offset something called arrhythmia, which is the natural rhythm of our heart. Most of the time an occasional arrhythmia in our hearts is fine.

However, when our heart rate goes out of sync, it can cause anything from very minor issues to serious problems like heart attacks.

The emerging impact of inflammation on both emotional symptoms and cardiovascular disease complicates the situation a bit.

People with depression may be more likely to have heart attacks due to arrhythmia, but we also have to remember the significant role inflammation plays in both depression triggering heart attacks.

The Rest of the Body

Depression has many physical effects on the body, and a lot of them aren’t 100% understood yet. The biology of depression is still kind of a mysterious puzzle. Some of the effects (or rather, connections) we know of include the following:


Symptoms of depression can include gaining or losing more weight than usual, feelings of nausea, unease, and other internal stomach problems.

These symptoms may partially follow from a thrown-off neurotransmitter balance. Inappropriate signals go to parts of the brain that tells us ”‘we’re hungry” when we’re not, or “I feel sick” when we aren’t.

Head, Joint, and Muscle Aches

Sometimes people with depression experience unexplained pains and aches throughout their body. Researchers have often explained these pains as related to neurotransmitters – like serotonin and dopamine imbalances. Pains may also relate to depression’s inflammatory connections.

Neurotransmitters and inflammatory chemicals fill many roles throughout the body, and if there’s an imbalance of them, we’re sure to feel the resulting problems.

So, What Can We Do About It?

Knowing that depression does quite the number on both our bodies and minds feels daunting, right? Fortunately, we can still do a lot about that! Here are some of the ways to manage the effects of depression:


Getting out there and getting active is one of the simplest ways to help. Something as small as a quick jog outside or 15-minute yoga break assists the chemicals in our brain by triggering dopamine release and elevating serotonin levels. And of course, exercise like yoga and weightlifting can strengthen our muscles while cardio can help our heart.


Like any engine, the body needs quality fuel to function at its maximum potential. Sugary and high calorie foods make you feel sluggish both mentally and physically. ‘Clean’ foods like lean meat and produce can help improve chemical flow in your brain, making you feel more energized and alert.

Because depression has biological bases, the chemicals from your food really can impact your symptoms. You don’t even have to go on a long term diet, as some individuals report feeling better after just eating cleaner for a week or two at a time!

Sleeping Better

While it’s not easy to simply ‘fix’ a sleep schedule, there are some steps you can take to help your circadian rhythm.

Light plays a role in our sleepiness, so something as simple as turning on all the lights as soon as you wake up or dimming the lights a few hours before you go to bed can help “reprogram” your brain back on track.

Melatonin is also an option, as it’s a hormone that naturally occurs in the body and one of the few easily purchasable in stores. Make sure to ask your doctor about the right dosage for you.


Antidepressants are sometimes looked down upon for being an “easy fix’” or a “crutch”. This isn’t true for many reasons, but in short, antidepressants are one of the few ways to “correct the imbalance” of neurotransmitters in our brains. They actually give back some of what we’re missing.

In Closing….

Hopefully we were able to get a better understanding of some of the biological aspects of depression. Depression symptoms are difficult to deal with, but don’t forget you’re not alone in this fight.

Here at Supportiv, we’re here to help you as much as we can, and whatever you need, we’ll be there every step of the way!

Just hit Chat Now and you’ll get to talk to someone supportive right away.