Depression is a common mental health disorder affecting about 11% of men and 16% of women in Canada throughout their lives — almost 3 million Canadians, and approximately 320 million people worldwide. However, of the 3 million struggling Canadians, only about 1/3 will seek help.
For decades, scientists and researchers have been trying to pinpoint what exactly causes depression. Is depression genetic? Although genetics may increase the risk of depression, it’s not a definitive indicator of whether someone will experience the mental health disorder. Being the complex disorder that it is, depression does not have a ‘number one cause.’ Many factors affect the risk, but how exactly does genetics play a role? Perhaps you’ve witnessed a family member experience depression, or you’ve been told you have the ‘depression gene’. However, simply being predisposed to depression in your family doesn’t necessarily mean you will have it, and people aren’t born with depression. Keep reading to learn about how genes affect depression, and what other factors have an impact.
Understanding genes VS heredity
When asking ‘is depression genetic’, it’s important to first identify the difference between genes and heredity. While these words are often used interchangeably, they don’t quite mean the same thing. Heredity is the process of passing down characteristics from one generation to another, including but not limited to genetic traits. Traits can be physical attributes such as eye colour, blood type, and even certain behaviours. Genetics, on the other hand, is the study of heredity, including theories about how genetics can play a part in the onset of depression.
What is depression?
Many of us have experienced episodes of feeling down and low, especially when going through a tough period in our lives. However, when the feeling of sadness and despair continue for a longer period of time, they can be caused by a serious but treatable condition known as depression. Depression is a psychiatric disorder characterized by various symptoms that can strike at any age. Most people experiencing depression for the first time in their early thirties.
Different types of depression
Major Depression: A serious condition that can affect many parts of your life. Major Depression Disorder (MDD) affects a great percentage of adults worldwide and can onset very spontaneously. It can also be caused by a reaction to trauma, loss, or a significantly stressful event. Those who suffer from MDD experience a depressed mood along with the inability to function, and thoughts or actions of suicide. Other characteristics that doctors look for are the inability to focus, anger and irritability, feelings of fatigue, loss of interest in usual activities and hobbies, feelings of hopelessness, guilt, and trouble sleeping. Experiencing symptoms for longer than 2 weeks can be an indication of MDD.
Depressive Reaction: Often less severe than MDD. Depressive Reaction is a temporary condition brought on by a specific circumstance or situation in life, also known as ‘stress response syndrome’. Although some symptoms can be quite severe, medical treatment isn’t needed typically unless there’s a change in sleeping patterns, appetite, or thoughts of suicide. In this case, the condition will continue to lessen within anywhere between two to six weeks.
Dysthymia: Also known as Persistent Depressive Disorder, is a type of depression that lasts for two years or longer among children and adults. Like Major Depression, dysthymia can cause a reduced interest in daily activities, feelings of hopelessness, a lack of productivity and self-esteem. These feelings can last for years and have a significant impact on relationships, hobbies, and professional life.
Postpartum depression: More commonly seen in first-time mothers. It’s a major depressive episode that can occur within the first few months after giving birth. Feelings can be short-term or last for many years.
Seasonal affective disorder: Or SAD, is a depressive episode that usually occurs during the winter months. Shorter days, the lack of vitamin D, and more time spent indoors can bring on a feeling of the blues.
Physical symptoms of depression
Symptoms of depression aren’t just mental, like feelings of hopelessness, guilt, fatigue, and loss of sleep and appetite. Rather, many people also experience physical symptoms that manifest in the body, including:
- Aching muscles and joints.
- Chest pain or heart palpitations.
- Changes in weight or appetite.
- Loss of sex drive.
- Digestive issues.
- Frequent illness due to a weakened immune system.
- Fatigue and exhaustion.
- Changes in sleep patterns like insomnia or oversleeping.
When unaddressed, these symptoms won’t just ‘go away’ — in fact, they can continue to worsen. Physical symptoms are the body’s way of alarming you that something is very wrong, and they shouldn’t be ignored. It’s important to see help as soon as physical symptoms of depression appear, especially when they’re paired with mental symptoms.
What causes depression?
Depression can look different for everyone. Although it’s not exactly known what causes depression, science supports that depression is the result of the combination of internal and external factors. The biology of our bodies is very complex, and like any other complex system, there is room for nuances.
Is depression genetic or hereditary? Researchers have determined that genetics and environmental stressors can lead to depression, not just one or the other. In this case, it’s nature and nurture.
What the science says:
How do scientists determine whether depression is hereditary? Identical twin studies are the primary form of research. Identical twins share 100% of the same genes, making it easier to separate whether a behaviour is caused by genes or environmental factors. Scientists study behavioural patterns in a twin who has Major Depressive Disorder. If genes are at play, we can expect a patient’s identical twin to be at a much higher risk of experiencing depression. Scientists have discovered that the twin without depression has a 35% chance of suffering at some point in time, whereas non-identical twins have about a 26% chance. This supports that depression is moderately related to genes.
Can depression be passed on through generations? Only about 40-50% of depression can be genetically passed down in a family. The other 50-60% is related to other factors like environment, past traumas, and other physical and psychological circumstances. Studies have also shown that someone with a parent or sibling with depression is three times more likely to be diagnosed in their lifetime, with women being more susceptible than men. It’s important to note that mental illness itself is not inherited, but the vulnerability to a mental illness is.
The impact of epigenetics
New studies in epigenetics suggest that there’s more to mental illnesses like depression than previously known. Epigenetics is an area of research that looks at how environmental factors can cause changes in the gene. So, the the idea that genes cannot be changed has been debunked — it’s no longer about nature vs. nurture, but both. Epigenetics gives us an explanation of how early experiences in childhood can have lifelong impacts. During developmental stages, our DNA (which is made of genes) collects chemical marks known as the epigenome. Different childhood experiences can rearrange the chemical marks, ultimately explaining why there can be differences in skills, behaviours, and health in identical twins. This is why genetic testing cannot accurately and definitively show whether or not we have the ‘depression gene’ — the likelihood of developing depression is made up of a variety of different factors, with genetics being one of them.
So, is depression genetic? Although genetics can play a role in how likely you are to develop depression, it’s not the only cause. Many researchers have concluded that there is no single gene that causes depression, but rather a combination of many genes, physical, and environmental factors. So, should you be worried if you have a parent or sibling who has depression? Not necessarily, but it never hurts to proactively seek help.
The link between serotonin and depression
Another factor that can lead to depression and symptoms of depression is serotonin levels. Serotonin is a neurotransmitter that communicates information throughout your brain to your body. It has many functions, one of them being its contribution to feelings of happiness and well-being, and its effect on sleep and appetite. Depression and anxiety are linked to lower levels of serotonin — which is often why doctors will prescribe SSRIs to treat depression. These types of medication boost the amount of serotonin the brain absorbs, leading to increased positive mood, better sleep, and more interest in daily routines like school, work, and hobbies.
Risk factors aside from genetics
When asking ‘is depression genetic’, it’s also important to look at other factors. Many factors or a combination of factors can increase the chances of depression including:
- Physical, sexual, or emotional abuse has been linked to the onset of depression later in life. The chances of depression increasing in people who may be more predisposed to depression.
- Certain medications can increase the likelihood of depression, including medication used to treat high blood pressure.
- Death or a loss of a loved one.
- Serious illnesses can trigger a reaction leading to the onset of depression.
- Substance abuse. Nearly 30% of people with substance abuse problems experience Major Depressive Disorder.
- Hormone imbalances.
- Extreme levels of stress.
- Physical or chemical changes in the brain.
The non-genetically related risk factors are a good reminder that genetic inheritance doesn’t necessarily mean that you will definitively suffer from depression. However, the opposite of that statement can also be true. Although no one in your family has experienced depression, it doesn’t mean that you will also never experience depression — it just becomes less likely.
Although there are no sure ways of preventing depression or experiencing a relapse, you can mitigate the impact of symptoms by:
- Reaching out to a trusted person when things get hard, whether it be a family member, a friend, or mental health professional.
- Studying yourself and finding ways to handle your stress, or discovering the triggers that can contribute to negative mood. For example, if you find that meditation leads to increased mood, try working it into your schedule regularly. Or, if a certain person triggers bouts of depression, ask yourself if it’s time to set boundaries.
- Taking physical care of your body and brain by getting enough sleep, having a well-rounded nutritious diet, and exercising two to three times per week
If you’re experiencing signs of depression, it’s important to seek professional help and follow up regularly.
There are many different ways to treat depression, including:
- Medication, often SSRIs, SNRIs or TCAs.
- Psychotherapy, including cognitive behavioural therapy (CBT)
- Lifestyle changes
Research has shown that your genes may influence how well a specific treatment will work for you. Certain genes affect how your body absorbs medication like antidepressants. It’s important to speak to your doctor or another mental health professional to set a plan that works for you. Remember, taking control of depression is a process that may take some trial and error — but it’s worth it to rediscover your happiness.
Tips for supporting others
If someone you care about is suffering from depression, you may be wondering how to best support them. Here are some tips for supporting others:
- Educate yourself to understand the effects of depression and how it can influence energy levels, mood, and day-to-day activities.
- Encourage them to seek help, even if their depression seems mild. It is important to get help as soon as depression symptoms appear to begin treatment early.
- Approach from a place of care. They worry no one cares or that they’ll be judged. Let them know that you’re here for them, and lend a non-judgemental listening ear.
- Everyday tasks can be difficult for someone with depression. Offer support by dropping off a few meals, helping them make a counselling appointment, or going with them to the doctor.
The importance of asking for help
Despite great efforts from researchers, doctors, and patients, the stigma of living with depression is very much prevalent. This is due to the many damaging misconceptions and misinformation that revolve around depression. Depression is not something you can simply ‘get over’. Rather, recovery typically involves a combination of lifestyle changes, medication, and counselling. Although the symptoms of depression can seem daunting, it is important to know that depression is treatable and there is absolutely no shame in asking for help.
Taking a proactive approach to depression
If you’re asking ‘is depression genetic?’, it’s clear that genes have some link to predisposition. Perhaps you’re worried you may experience depression at some point in your life due to your family’s genetic predisposition. If so, consider taking proactive steps to reduce the likelihood of developing depression. Working with a counsellor before issues arise or worsen can equip you with the skills and knowledge to better manage triggers and stressors.
A counsellor can also help you figure out what steps to take to protect your mental health based on your personal experiences and family history, and most importantly, to reduce the stigma around seeking help. Wellin5’s smart platform matches you to a counsellor who meets your unique needs — helping you set a customized plan to regain control of your life. Our counsellors are equipped to help you deal with any symptoms of depression, giving you the support you need to feel better. Take the first step.