However, everything psychological is also biological, and learning how your brain works can be a daunting task; especially if you are in a vulnerable place. Thus, today, we are going to go through the basic biology and science of how Depression works in the brain.
Our entire bodies are made up of what are called neurons or nerve cells. Neurons are at work every time we think, or do anything. Although there are many different types of neurons throughout our bodies, responsible for different functions, they are all comprised of the same basic three parts: Dendrites, which receive information from other neurons. The soma, or cell body which holds the nucleus of the cell (and all of that other fun stuff), and finally the axon, a tail-like extension of the neuron which sends information to other neurons from its axon terminals. Many axons are also coated in what is called the myelin sheath, which is a protective layer of fatty tissue that speeds up the transmission of messages between neurons.
Neurons fire, thus sending information, whenever they are triggered by sensory stimuli (like sharing a first kiss with a loved one), or when they receive information from neighboring neurons.
The average human has about 100 billion neurons in the brain alone, so you can imagine how cozy they all are. Except that neurons never really touch each other. In fact, they are separated by what is called a synpase, which essentially decorate the dendrites of every neuron. The space between the axon terminal of a sending neuron and the receptores located on the dendrites of the receiving neuron is called the synaptic gap. When a neuron fires, it sends messengers to its neighboring neurons, called neurotransmitters.
Now, there are many different types of neurotransmitters. The ones you will likely be familiar with are Endorphins, Dopamine, Norepinephrine and Serotonin. All of the different kinds of neurostransmitters are either excitatory, or inhibatory, meaning their goal is either to increase or decrease the likelihood that a neighboring cell will fire.
Endorphins, as many of you know, are responsible for things such as relief from pain and feelings of pleasure, and Dopamine related to attention, learning, and movement. Norepinephrine affects our eating and sleep habits, and Serotonin is closely linked with neurobiological functions such as mood, sleep, impulsivity, aggression and appetite. A lack of neurontransmitter Seratonin is strongly correlated with Depression, and although it is not fully to blame, research indicates it plays a large role.
There is a particular process at work between the transmission of neurotransmitters, however, that is important to understand. This is the process of Reuptake. Reuptake is the process by which the sending neuron quickly re-absorbs their neurotransmitters after the signal has been received by the receiving neuron. This is important to understand because many classes of anti-depressants rely heavily on this process to be effective. The process of reuptake can actually prevent receiving neurons from effectively passing the message on to their neighboring cells.
Now, if you or someone you love has been diagnosed with Depression, or Major Depressive Disorder, it is likely they are on, or have tried one or more of anti-depressants. I want to be clear in stating that an anti-depressant medication is as much a crutch as an insulin shot is a crutch for a person with Diabetes. For many, many years, I refused to take anti-depressants because I conformed to some societal-belief that they shouldn't be required. But ah, my friend, in many cases, you would be wrong to think such a thing.
The anti-depressant class of SSRI's (Selective Serotonin Reuptake Inhibitors) increases the availability of the neurotransmitter Serotonin by slowing down the process of Reuptake from the sending neuron, giving the receiving neuron more time to do it's job, and pass on the message (and chemical).
There is also the class of anti-depresants called SNRI's (Serotonin Norepinephrine Reuptake Inhibitors). These anti-depressants work the same as SSRI's except that they affect both the neurotransmitter of Serotonin and Norepinephrine.
And there you have it! The basics of the biology of Depression.
Of course,there are other factors at play, including certain areas of the brain, as well as environment and past experience, but those are all topics we will cover later.
Alycia
