In her 1988 novel The Bean Trees, Barbara Kingsolver wrote, "Sadness is more or less like a head cold — with patience, it passes. Depression is like cancer."
But setting Kingsolver's apt analogy aside, what does "depression," the condition that the World Health Organization estimates affects about 350 million people of all ages worldwide, actually involve?
Is depression a disease?
Many people, including Kingsolver, liken depression to an illness.
But according to John Grohol, the founder of mental health social network Psych Central, depression is actually categorized as a mental "disorder", and not a disease, because the words have two different meanings.
"A disorder simply means something that is out of the ordinary, which depression and other mental disorders are," Grohol wrote in a post on the website. "They are more specifically a cluster of symptoms that research has shown to correlate highly with a specific emotional state."
Grohol said that diseases, on the other hand, are characterized by some abnormally functioning "organ or component within the body."
And while we do consider the brain an organ, and although doctors can see abnormalities on the brain scans of patients diagnosed with depression, not enough about the science is known to be able to tell whether or not those aberrations are causing depression or if they're the result of it.
What is depression?
Major depressive disorder, or clinical depression, is most commonly characterized as a deep, prolonged sadness.
According to the American Psychiatric Association, depression can affect every area of daily life. Losing pleasure in activities you once enjoyed, like writing, running or spending time with friends, is sometimes an early warning that something isn't right.
Other signs that your ability to function has decreased due to depression include a loss of appetite, irregular sleep patterns, increased fatigue, feeling worthless or guilty all the time, difficulty making decisions and thoughts of death and/or suicide.
There are also many different forms of depression. Under its general umbrella are persistent depressive disorder (an episode of major depression lasting two or more years); postpartum depression (the feelings of exhaustion and despair that plague mothers who have recently given birth); and seasonal affective disorder (depression whose onset occurs during the winter months), to name a few.
What causes depression?
Doctors and researchers are working hard to find out how closely biology is linked to depression, but much of the science is still murky. So what do they know?
Depression might be linked to gender
According to Mayo Clinic, women are diagnosed with depression nearly twice as often as men are. Researchers think that horomone changes during puberty "may increase some girls' risk of developing depression," while horomones linked to pregnancy are proven to lead to postpartum depression in between about 10% and 15% of women.
Serotonin plays a role
Acting as a neurotransmitter, serotonin is like a mailman whose job is to relay messages from one area of your brain to another. Though it isn't proven, there is a school of research that believes that when the brain fails to produce enough serotonin, it can cause a chemical reaction that leads to depression. SSRIs, a common medication prescribed for patients with depression, attempts to boost serotonin levels to remedy this effect.
One gene in particular is being studied
In 2011, London researchers who studied 800 families who had two or more depressed members were able to isolate one gene, chromosome 3p25-26, which they believe is linked to depression. But, as other researchers say...
Many genes likely play a role
Scientists are investigating many other "isolated" causes of depression, including a smaller hippocampus in those diagnosed and other specific genes, like SLC6A15, that could be to blame. But according to Healthline, "It is more likely a combination of genes that lead to the disorder."
In addition to the biological factors, there can also be unrelated environmental factors that can explain a sudden change in mood.
According to WebMD, experiencing possible sources of trauma — like abuse, death of a loved one, a serious illness or substance abuse — can lead to the onset of depression. But for some people, life can be going great by all available metrics, and depression just happens anyway.
"Depression is a very difficult illness to treat because it has genetic underpinnings with environmental stressors," Dr. Scott Krakower, the assistant unit chief of psychiatry at Zucker Hillside Hospital North Shore-LIJ Medical Group, said to WebMD. "The genetics are not entirely understood."
It's important to understand that if you have depression, you're not in any way deficient, or "other."
How do you treat depression?
Since the science behind what causes depression is still emerging, finding a treatment that works for your individual needs can be tricky, and requires a bit of patience as you work with your doctor to find out what suits your needs.
A preliminary course of action that might be recommended to you as treatment could be to speak with a mental health professional, like a psychologist, whose job is to help you make sense of your feelings.
However, if medication is determined to be your best course of action, whatever your doctor eventually prescribes will be based on what they believe is best suited to your individual needs. Mayo Clinic lists some of the most common medications.
How to get help:
If you're even slightly concerned that you might be depressed, make an appointment for a consultation with a doctor. While there are lots of resources available online, nothing can help you as much as speaking to a doctor in the flesh. Check ZocDoc for practitioners in your area who take your insurance if you don't have a primary care physician.
Talking to friends and family can also be helpful. Dr. Adele Viguera, associate director of the perinatal and reproductive psychiatry program at the Cleveland Clinic in Ohio, told Everyday Health that while it might not make you feel better right away, having the people you love understand what you're going through can be a great asset in the fight against depression.
"Whenever anyone's having a hard time, they can benefit from encouragement from friends and family that things will get better," she said. "Friends and family who are supportive remind you that this too shall pass."
If you're having thoughts of harming yourself in any way, there are a number of toll-free hotlines and instant chat services that you can utilize:
— National Suicide Prevention Helpline: 1-800-273-TALK
— United Way Helpline: 1-800-233-HELP
— The Trevor Helpline (for LGBTQ crisis intervention): 1-800-850-8078