Depression isn’t clearly understood in the same way as many other brain disorders. We know what the symptoms are, and a diagnosis is made based on a person displaying a collection of these. There’s no blood test or brain scan that can definitively make a diagnosis — only a mental health professional can do that.
A person exhibiting a number of the symptoms listed below, consistently for an extended period of time, may have depression:
- A persistent feeling of hopeless, emptiness, sadness, or irritability which interferes with day-to-day activities.
- A decreased interest in or pleasure from activities that you used to enjoy.
- Considerable weight loss or gain.
- Insomnia or increased sleep.
- Restlessness or slowed behavior observable by others.
- Fatigue or loss of energy.
- Feelings of worthlessness or excessive guilt.
- Trouble thinking, paying attention, or making decisions.
- Recurrent thoughts of death or suicide.
What Depression Is Not
First, let’s get clear about what depression is not. It’s not people with too much time to think and not enough friends or stimulating interests in their lives. It’s not people who just need to get over it already, slap a smile on their face, and think happy thoughts. It’s not people who don’t go to church often enough, or exercise, or eat the right foods, or meditate.
While all of these things can be part of a mentally healthy lifestyle that helps a person stay out of depression, it’s a complex illness with a basis in brain neurochemicals, thought patterns, and many other contributing factors, such as life events, environment, biochemicals, stress, and genetics. (Read more: What Depression Looks Like In Your Brain)
Depression is real, and it can kill. It almost killed me. (Read my story here.) According to the National Institute For Mental Health, “In 2014, an estimated 15.7 million adults aged 18 or older in the United States had at least one major depressive episode in the past year. This number represented 6.7% of all U.S. adults.”
In the 1960s, we were told depression was caused by a deficiency of the neurotransmitter norepinephrine. Then, a still popular theory blamed depression on too little serotonin. Today, we know that it’s much more complicated than either of these explanations.
What Depression Is
Basically, a depressed brain looks just like any other brain. We all have the same primary brain structure although the neuronal connections, determining the activation of and communication between brain circuits, are unique to each one of us. The particular circuits excited over and over in your brain become the go-to default patterns for you controlling every thing you do.
In The Upward Spiral: Using Neuroscience to Reverse the Course of Depression, One Small Change at a Time, Alex Korb PhD explains:
In depression, there’s nothing fundamentally wrong with the brain. It’s simply that the particular tuning of neural circuits creates the tendency toward a pattern of depression. It has to do with the way the brain deals with stress, planning, habits, decision making and a dozen other things — the dynamic interaction of all those circuits. And once a pattern starts to form, it causes dozens of tiny changes throughout the brain that create a downward spiral.
The many brain circuits overlap, rely on, and influence each other. “If you’re feeling depressed or happy or hungry or horny, it’s the result of the way a whole bunch of circuits are impacting each other” writes Korb.
The Neurochemicals Of Depression
There are several neurotransmitter systems in your brain. Korb likens these to the flight map in the back of an in-flight magazine showing all the cities an airline flies to and from. A neurotransmitter system involves all of the neurons that release or react to a particular neurotransmitter, like the Delta system would be all the cities Delta connects to.
Each neurotransmitter system influences and is influenced by depression, and to oversimplify, tends to contribute to specific symptoms. The neurochemicals involved in depression are:
Serotonin improves willpower, motivation, and mood.
Norepinephrine enhances thinking, focus, and dealing with stress.
Dopamine increases enjoyment and is necessary for changing bad habits.
Oxytocin promotes feelings of trust, love, connection, and reduces anxiety.
GABA increases feelings of relaxation and reduces anxiety.
Melatonin enhances sleep quality.
Endorphins provide pain relief and feelings of elation.
Endocannabinoids improve your appetite and increase feelings of peace and well-being.
Unfortunately, healing depression isn’t as simple as just increasing the level of any one chemical. That may be one part of the solution, but it’s much more complex than that because all the chemicals interact and affect other bodily systems. It’s a delicate balancing act.
It’s All Connected
One brain region can be involved in several chemical circuits. Changing any aspect of a neurotransmitter system, from altering the levels produced to allowing more time to bind to the next neuron, can affect other systems in a variety of ways.
Think of each brain region like an airport, and each circuit as a different airline flying off to different parts of the country. Just s airlines operate independently, but rely on the same airports, independent neural circuits rely on the same brain regions. And because neural circuits rely on some of the same brain regions, they interact dynamically. With air travel, backups in Chicago can lead to delays in Denver or cancellations in Kansas City; similarly, in the brain increased emotional amygdala activity can change what the anterior cingulate focuses on, as well as the habits controlled by the dorsal striatum.
Changing Your Brain’s Pattern
Your specific neural circuits — decision-making, habit, social, stress, memory, and more — can lead to depression. If you have depression, it’s important to understand that this doesn’t mean your brain is damaged goods. It means your neural circuits have connected in patterns that create depression for you.
Because of neuroplasticity, the brain’s ability to physically change form and function based on thoughts, behaviors, and experiences, it’s possible to change your brain to become happier and healthier. With all the neurotransmitters influencing each other and all of the brain circuits interconnected, consistently implementing simple practices to alter the activity of any one system can have ripple effects across the whole system.
Hence, meditating, exercising, getting more sleep, reducing stress, eating a brain healthier diet, or counseling can be part of a solution that helps alter the chemical balance to kickstart a brain out of depression. The challenge is to find out what works for your brain.