It’s perfectly natural to feel sad at certain times in your life. Sadness can be brought on by the loss of a loved one, a breakup, moving away from friends and family, struggling financially or working in a job you don’t enjoy.
Sadness comes in waves and usually passes with time. However, if it does not pass or if sadness leaves you struggling to cope with everyday life; you could be suffering from depression. Understanding the difference between sadness and depression as well as types of depression, symptoms and how to treat depression is important. It can help you get the support or treatment you need before the condition becomes severe.

How depression is different from sadness or grief
Depression is a mood disorder that causes an unrelenting feeling of sadness and loss of interest. It’s more than just a bout of the blues and it’s not something you can simply “snap out of”. Depression tends to be a long-term condition and may require treatment in the form of medication, psychotherapy or both.
Sadness is just one element of depression. It’s a human emotion that can leave you feeling upset or in emotional pain. You get varying degrees of sadness but like any other emotion, it’s temporary and passes with time. Between bouts of sadness, you should also have moments of being able to laugh and experience joy.
Depression is different in that it is not an emotion, it is a mental illness. If left untreated, depression symptoms may last a long time and will impair many aspects of your life; from socialising, working, developing relationships and coping with everyday tasks and activities you usually enjoy.
Depression is one of the most common mental disorders in the world but the good news is that most people respond well to therapy and medical treatment. Even the most severe cases of major depression can be treated.
The earlier that treatment can begin, the more effective it is.
What causes depression?
There is no number one cause of depression. It’s a mental disorder that is so complex, even the science on depression is incomplete; despite the fact that depression is the most common mental disorder in the world.
Similarly, no two people will experience depression in the same way. This is because depression is a convoluted combination of brain chemicals, genetic makeup, life stress, early trauma and medical problems. All these forces interact to bring on depression.
Common wisdom says emotions reside in the heart. But, as mentioned, depression is not an emotion. It’s an illness. Therefore, scientists have looked at human biological makeup to find the causes of depression and it’s now common knowledge that brain chemicals are involved in depression. Billions of chemical reactions make up the dynamic system that is responsible for our moods, thoughts, perceptions and how we experience life.
Scientists have also identified genes that make certain people vulnerable to low moods and erratic emotions. They’ve found that nerve cell connections, nerve cell growth and the functioning of nerve circuits have a major impact on depression.
4 theories on what causes depression
The science behind what causes depression is ongoing and there are many theories of how the mental illness develops. Here are four key factors that researchers have uncovered in their search for the root cause of depression.
1. Your genetic code
According to a Stanford Medicine study on Major depression and Genetics, “Heritability is probably 40-50% and might be higher for severe depression. This could mean that in most cases of depression, around 50% of the cause is genetic and around 50% is unrelated to genes (psychological or physical factors). Or it could mean that in some cases, the tendency to become depressed is almost completely genetic, and in other cases it is not really genetic at all.”
Therefore, the study notes, “If someone has a parent or sibling with major depression, that person probably has a 2 or 3 times greater risk of developing depression compared with the average person (or around 20-30% instead of 10%).”
Two people with two different sets of genes could experience the same traumatic life event, yet one develops depression and the other doesn’t. Different types of depression – bipolar disorder, psychotic depression and dysthymia – may involve different genes.
2. Early childhood experiences
A large number of people who suffer from major depression can link it back to negative experiences in early childhood. This may be a traumatic event like the death of a parent or sibling, neglect, abandonment or physical or sexual abuse.
These experiences in early childhood create changes in the brain that are hard to “rewire” but it is possible. Therapies such as cognitive behaviour therapy, psychodynamic therapy and transcranial magnetic stimulation have proven to be successful in reframing how one views these childhood experiences and what impact they have on one’s life.
3. Major life events
Immediate or prolonged major life events can trigger depression in someone who is at risk of the mental illness.
Immediate major life events | Divorce or marital strife Breakup of a relationship Death of a loved one Retrenchment or fired from a job Business failure Loss of home or income due to a natural disaster Serious physical injury Childbirth (postpartum depression) |
Prolonged stressful life events | Unemployment Homelessness Chronic illness or pain Abusive or unhealthy relationship Executive burnout |
4. Substance abuse
Depression and substance abuse – alcohol and drugs – often go hand-in-hand with major depression. Therapists that treat drug and alcohol addiction refer to this as co-occurring disorders. About one in four depressed people (25%) also struggle with substance abuse. Likewise, one in five (20%) of alcoholics and drug addicts suffer from depression.
Substance abuse can trigger or intensify feelings of guilt, isolation, loneliness, sadness and hopelessness which are symptoms of depression. Similarly, the symptoms of depression can drive some people toward substance abuse as a way of coping with their mental illness.
Consuming drugs or alcohol to self-medicate depression symptoms can increase your risk of addiction. This is because regularly drinking or using drugs can make you feel euphoric and provides temporary relief from the debilitating symptoms of chronic depression.
9 types of depression
There are many types of depression. Chemicals in your brain cause some types of depression while events in your life causes other types. It’s important that you speak to your doctor for a proper diagnosis of the type of depression you may be suffering from and the best depression treatment for you.
1. Major depressive disorder
Major depressive disorder or major depression is when you feel depressed most of the time for most days of the week.
You may have major depression if you have five or more of these symptoms on most days for 2 weeks or longer. At least one of the symptoms must be a depressed mood or loss of interest in activities.
Symptoms of major depressive disorder
Most common | Poor appetite or repeatedly going over thoughts |
Mood | Anxiety, apathy, general discontent, guilt, hopelessness, loss of interest, loss of interest or pleasure in activities, mood swings or sadness |
Whole body | Excessive hunger, loss of appetite or fatigue |
Behavior | Agitation, excessive crying, irritability, restlessness or social isolation |
Sleep | Early awakening, excess sleepiness, insomnia or restless sleep |
Cognitive | Lack of concentration, slowness in activities or thoughts of suicide |
Weight | Weight gain or weight loss |
Treatment for major depressive disorder
The mainstay of treatment for major depressive disorder is usually medication, talk therapy or a combination of the two. Research suggests that these treatments may normalise brain changes associated with depression.
Therapies | Cognitive behavioral therapy Talk therapy focused on modifying negative thoughts, behaviour and emotional responses associated with psychological distress Behaviour therapy Therapy focused on modifying harmful behaviours associated with psychological distress Psychotherapy Treatment of mental or behavioural disorders through talk therapy |
Medication | SSRIs Eases symptoms of depressed mood and anxiety Antidepressant Medication designed to help relieve symptoms of depression; some antidepressants have other uses such as treating chronic pain and certain anxiety disorders Anxiolytic Relieves anxiety and tension; may help with sleep problems Antipsychotic Reduces or improves the symptoms of certain psychiatric conditions |
Medical procedures | Electroconvulsive therapy (ECT) Treating mental illness by sending electric currents through the brain to trigger a seizure; also known as shock treatment Transcranial magnetic stimulation (TMS) A non-invasive form of brain stimulation in which a changing magnetic field is used to cause electric current at a specific area of the brain through electromagnetic induction Vagus Nerve Stimulation (VNS) Sends regular, mild pulses of electrical energy to the brain via the vagus nerve, through a device that is similar to a pacemaker; there is no physical involvement of the brain in this surgery and patients cannot generally feel the pulses |
2. Persistent depressive disorder
Persistent depressive disorder is depression that lasts for two years or longer. It’s a term used to describe two conditions previously known as dysthymia (low-grade persistent depression) and chronic major depression.
Causes of dysthymia/PDD | Chemical imbalance in the brain Family history of the condition History of other mental health conditions, such as anxiety or bipolar disorder Stressful or traumatic life events, such as the loss of a loved one or financial problems Chronic physical illness, such as heart disease or diabetes Physical brain trauma, such as a concussion |
Symptoms | Change in your appetite (not eating enough or overeating) Sleep too much or too little Lack of energy or fatigue Low self-esteem Trouble concentrating or making decisions Feel hopeless |
Treatment | Psychotherapy, medication or a combination of the two |
3. Bipolar disorder
A person with bipolar disorder has mood episodes or “mood swings” that range from extreme high energy to very low depressive periods. The old-fashion term for bipolar disorder is manic depression.
Bipolar mood episodes last from a few days to months at a time and may also be associated with suicidal thoughts.
When you’re in a low phase, you have symptoms of major depressive disorder. When you’re in a high phase, you experience manic symptoms.
Symptoms of bipolar disorder
Depressive symptoms | Lack of energy Feeling worthless Low self-esteem Suicidal thoughts |
Manic symptoms | Increased energy Excitement Impulsive behavior Agitation Restlessness |
Treatment for bipolar disorder
A formal diagnosis of bipolar disorder is required and then you will be prescribed medication that will bring your mood swings under control. These are mood stabilisers which will help you regardless of whether you’re in a high or low episode.
FDA-approved medicine | Lithium Seroquel Latuda Olanzapine-fluoxetine combination |
Off-label medication | Lamotrigine; anti-convulsion Vraylar; anti-psychotic |
Therapy | Psychotherapy for individuals and family members |
Note
Traditional antidepressants used for major depression are not typically prescribed or recommended as first-line treatment for bipolar disorder. In addition to not being proven efficient, a small percentage of people with bipolar disorder experience adverse side-effects or increased frequency of bipolar episodes when taking anti-depressants.
4. Seasonal affective disorder (SAD)
Seasonal affective disorder (SAD) is a form of major depression that is triggered by the autumn and winter season, when days grow short and you get less and less sunlight. SAD should go away in spring and summer, as soon as the weather improves, the sun comes out and the days warms up.
Reduced sunlight or lack of sunlight can cause a drop in serotonin and melatonin levels which may trigger depression. Serotonin is a brain chemical (neurotransmitter) that affects our moods. Melatonin plays a role in sleep patterns and stabilising moods.
Symptoms and treatment for SAD
SAD symptoms | Social withdrawal School or work problems Substance abuse Other mental health disorders such as anxiety or eating disorders Suicidal thoughts or behavior Trouble sleeping (insomnia) Poor appetite Weight loss Agitation or anxiety |
SAD treatment | Anti-depressants work well for SAD as well as light therapy. This is where you sit in a special bright light box for between 15 to 30 minutes each day. |
5. Psychotic depression
Psychotic depression involves symptoms of major depression along with psychotic symptoms. It is a subtype of major depression and it’s a severe depressive illness which includes some form of psychosis.
Psychosis is a mental disorder characterised by a disconnection from reality. It may occur as a result of a psychiatric illness such as schizophrenia or may be caused by a health condition, medication or drug use.
Symptoms of psychotic depression
Common symptoms | Agitation Anxiety Constipation Hypochondria Insomnia Intellectual impairment Physical immobility |
Psychosis | Hallucinations Hearing a voice telling you that you are no good or worthless Delusions Intense feelings of worthlessness, failure or having committed a sin Paranoia Wrongly believing that others are trying to harm you |
Treatment for psychotic depression
Hospitalisation | Psychotic depression is usually treated on an inpatient basis in hospital. The patient can be closely monitored by health professionals and prescribed medication to stabilise their moods. |
Anti-depressants | Same as for major depressive disorder |
Anti-psychotic drugs | Aripiprazole (Abilify) Asenapine (Saphris) Cariprazine (Vraylar) Olanzapine (Zyprexa) Quetiapine (Seroquel) Risperidone (Risperdal) |
Therapy | Psychotherapy for individuals and family members |
6. Peripartum or postpartum depression
Peripartum or postpartum depression is a severe case of the ‘baby blues’ that women can experience after childbirth. If you develop postpartum depression, you are at greater risk of developing major depression later in life. That’s why it’s important to speak to your doctor and get help for this type of depression early rather than later.
Postpartum depression if left untreated can lead to thoughts of suicide and suicide itself.
Symptoms | Insomnia Loss of appetite Intense irritability Difficulty bonding with the baby Suicidal thoughts |
Treatment | Counselling Anti-depressants Hormone therapy Hospitalisation |
7. Premenstrual dysphoric disorder (PMDD)
Premenstrual dysphoric disorder (PMDD) is a form of depression many women experience at the start of their menstrual period, along with other symptoms. It’s a much more severe form of ‘pre-menstrual tension’ (PMS) and can morph into a chronic medical condition.
Symptoms of PMDD appear during the week before menstruation and end within a few days after your period starts. These symptoms often disrupt everyday tasks and how well you cope with your home and work environment.
Symptoms | Depressed mood Anger or irritability Trouble concentrating Lack of interest in activities once enjoyed Moodiness Increased appetite Insomnia or the need for more sleep Feeling overwhelmed or out of control Physical symptoms such as belly bloating, breast tenderness and headaches |
Treatment | Changes in diet to increase protein and carbohydrates Decrease intake of sugar, salt, caffeine and alcohol Regular exercise Stress management Vitamin supplements (such as vitamin B6, calcium, and magnesium) Anti-inflammatory medicines Selective serotonin reuptake inhibitors (SSRI)Birth control pills |
8. Situational depression
Situational depression is a term used to describe a mental illness brought on when a person is having trouble managing or adapting to a stressful event in their life. This could be the death of a loved one, a divorce or marital problems, losing your job or relocating.
Doctors also call situational depression “stress response syndrome”. It is usually short-term depression that can be treated successfully with medication, therapy, exercise or diet.
Causes of situational depression
Stressful events | Relationship or marital problems, such as constant fighting or divorce Situational changes, such as retirement, leaving home or having a baby Negative financial situations, such as money problems or losing a job The death of a loved one Social issues at school or work, including bullying and low self-confidence Life-or-death experiences such as physical assault, combat or a natural disaster Medical illness such as cancer, loss of limb or a brain injury Living in dangerous times or an unsafe location |
Biological factors | Abnormalities in brain structure and chemistry Hormonal abnormalities Changes in genetics |
Treatment for situational depression
Medicine | Selective serotonin uptake inhibitors (SSRIs), such as sertraline (Zoloft) and citalopram (Celexa) Dopamine reuptake blockers, such as bupropion |
Lifestyle changes/support | Cognitive behavioral therapy (CBT). Getting exercise Establishing healthy sleeping habits Getting more rest and relaxation Eating more healthfully Strengthening your social support system |
9. Atypical depression
Atypical depression describes a pattern of depressive symptoms. If you have atypical depression, a positive event can temporarily improve your mood. Atypical depression is one of the most common types of depression and someone living with it does respond well to medication and therapy.
Atypical depression is different to sadness because many people who suffer from it also complain of having uncomfortable physical symptoms; the most common being a feeling of heaviness in their arms and legs. They tend to oversleep and overeat, feel worse in the evenings, experience phobias and paranoia and are highly sensitive to rejection or any form of criticism.
Someone with atypical depression does not feel sad or hopeless all the time; they do cheer up momentarily in response to sympathy, compliments or visits with family and friends.
Symptoms | Sadness or depressed mood most of the day or almost every day Loss of enjoyment in things that were once pleasurable Major change in weight Insomnia or excessive sleep almost every day A state of physical restlessness or being rundown that is noticeable by others Fatigue or loss of energy almost every day Feelings of hopelessness or worthlessness or excessive guilt almost every day Problems with concentration or making decisions almost every day Recurring thoughts of death or suicide, suicide plan or suicide attempt |
Treatment | Anti-depressants Cognitive behavioral therapy Counselling |
Is depression hereditary?
Yes, depression is known to run in families and can be passed down from your parents or grandparents. Genetic factors do contribute to the risk of developing depression but it does not mean you will get depression even if the mental illness is prevalent in your family.
According to the US National Library of Medicine, people who have a first-degree relative – a parent or sibling – with depression appear to have a two to three times greater risk of developing the condition than the general public. However, many people who develop depression do not have a family history of the mental disorder, and many people with an affected relative never develop depression.

How is depression diagnosed
If you suspect you are living with depression, it’s important that you speak to your doctor or a licensed mental health expert for an evaluation and proper diagnosis. This involves a depression screening where you will complete a battery of questions.
Your doctor may also do a general physical exam and take blood to rule out if you have any other medical issues that are causing depression symptoms. Certain illnesses, hormonal changes and medications can produce symptoms similar to depression.
What is DSM?
The Diagnostic and Statistical Manual of Mental Disorders (DSM) is one of the most popular evaluations used by mental health professionals to diagnose depression. DSM contains descriptions, symptoms and other criteria for diagnosing mental disorders.
DSM provides a common language for clinicians to communicate about their patients and establishes consistent and reliable diagnoses that can be used in the research of mental disorders. It also provides a common language for researchers to study the criteria for potential future revisions and to aid in the development of medications and other interventions.
DSM has been periodically reviewed and revised since it was first published in 1952. The previous version of DSM was completed nearly two decades ago and since that time, there has been a wealth of new research and knowledge about mental disorders.
There are 5 DSM categories; the most recent update is DSM-5. The criteria listed in the DSM-5 will help your doctor determine whether or not you have depression and it’s used by your insurance company to reimburse your or a family member for therapy and medicine required to treat your type of depression.
What is the DSM-5 definition of depression?
The DSM-5 outlines the following criterion to make a diagnosis of depression. The individual must be experiencing five (5) or more symptoms during the same 2-week period and at least one of the symptoms should be either a depressed mood or loss of interest or pleasure.
- depressed mood most of the day, nearly every day.
- markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day.
- significant weight loss when not dieting or weight gain, or decrease or increase in appetite nearly every day.
- a slowing down of thought and a reduction of physical movement (observable by others, not merely subjective feelings of restlessness or being slowed down).
- fatigue or loss of energy nearly every day.
- feelings of worthlessness or excessive or inappropriate guilt nearly every day.
- diminished ability to think or concentrate, or indecisiveness, nearly every day.
- recurrent thoughts of death, recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide.
To receive a diagnosis of depression, these symptoms must cause the individual clinically significant distress or impairment in social, occupational or other important areas of functioning. The symptoms must also not be a result of substance abuse or another medical condition.
When to seek help?
Only a doctor or a mental health professional such as a psychologist or psychotherapist can make an accurate diagnosis of depression and recommend the best treatment for your type of depression. It’s important that you seek professional help for depression earlier rather than later because the symptoms may worsen and leave you feeling hopeless and helpless with thoughts of suicide.
Certain illnesses and certain medication can cause symptoms that mimic depression. It’s a good idea to have a complete medical examination as part of the process of diagnosing and treating depression and deciding on the right depression treatment protocol for you.
Disclaimer
The information in this article is only meant to be used as a tool to help you recognise depression symptoms and help you talk to your doctor or loved ones. It does not substitute medical intervention for an accurate diagnosis of depression.