Depressive Disorder

Major Depressive Disorder, as known as depression, is a common mental disorder. People living with depression feel down most of the time and could not control their emotions. Depression can be chronic or recurrent, causing lowered work efficiency, academic performance and social ability, or even suicidal thoughts and behavior.

According to World Health Organization, there are around 350 million people living with depression worldwide and only less than 25% of them receive treatment and related services. In Hong Kong, there are more than 300,000 people living with depression. The number of people living with depression is predicted to shoot up in the coming 20 years; in 2020, the prevalence of depression would only be second to heart disease on the Global Disease List. Depression is posing a heavy burden to the world’s health and its consequence shall not be ignored.
Low mood or Depression?
Everyone has their low points in life and it is natural to feel down and sad at those moments especially when we go through break-ups or bereavement of loved ones. Yet, we usually get over these feelings and emotions after a period of time. So, do you know what differences there are between depression and low mood?
Low mood VS Depression
Few hours to few days Duration The feeling of sorrow and despair last for at least two weeks, or even longer, lasting for from a few weeks to few years.

Self-esteem might temporarily decrease, yet could be boosted in a short period of time. There is a sense of hope for the future. Self-image and Insights for future People with depression have poor self-image and regard themselves as losers. They attribute unfortunate events to themselves. They think that problem would last for long and also think negatively about people and things around. They as well lose hope for the future

Not much impact on daily life Daily life Significant adverse impact on daily life, job performance (deterioration in attention, decision making power etc.) and interpersonal relationships

Feeling down but not necessarily negative. No significant changes in physiology and daily life. Symptoms Persistent depression and grief, loss of interest in all activities, arisen thoughts of suicide in severe condition. Changes in appetite and sleep patterns.
* Reference: United Centre of Emotional Health & Positive Living
Many of us may experience a few symptoms of depression even though we are not living with depression: persistent low mood, loss of interest, urge to escape from all worries and troubles etc. If we could put more attention to our own emotional states and face our emotions undauntedly, we might be able to stop the situation from exacerbating.
Symptoms of Depression
What are the symptoms of depression? No two people experience exactly same depressive symptoms. Some people experience more, while some experience less; some experience the symptoms for a longer period of time, while some experience more severe symptoms.
According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), symptoms of Major Depressive Disorder are:

1.Depressed mood:
feeling depressed most of the day, nearly every day (e.g., feeling empty, hopeless, sad)

2.Decreased interest:
decreased interest in most activities, most of each day (subjective feeling or observation from others)

3.Change in appetite/weight change:
significant change in appetite (including gain or loss), or significant gain or loss in weight without a change in eating patterns (more than 5% of body weight in a month)

4.Difficulty in sleeping:
insomnia or excessive sleep nearly every day

5.Psychomotor agitation or retardation:
demonstration of psychomotor agitation or retardation nearly every day observed by others

fatigue or loss of energy nearly every day

7.Feelings of worthlessness:
feeling worthless or excessively guilty nearly every day (the guilt does not only stem from self-blame and guilt for the diagnosis)

8.Diminished concentration:
diminished ability to concentrate or make decision nearly every day

9.Recurrent suicidal thoughts:
recurrent thoughts of death that are more than mere fear of death; recurrent suicidal thoughts, even with a concrete plan or trial.
According to the American Psychological Association (APA)'s diagnostic criteria, an individual would be diagnosed with depression when at least 5 of these symptoms of depression are present (depressed mood and loss of interest must be included); these symptoms have to be present every day for at least two weeks, which significantly impair the individual’s daily, occupational or social functions.
Even though you experience the above situations, it does not necessarily mean you that you are living with depression. Please contact related healthcare professionals (e.g. psychiatrists, clinical psychologists) for accurate assessment.
It is hard to tell if someone is living with the symptoms above or that they are living with depression. Many people might be troubled by depression, yet they still strive to live up to their best potential and contribute as a member of the labour force as usual. It is just as what we have mentioned in last section, people with mental illness can also possess mental health.
Causes of Depression
What are the causes of depression? Depression does not spring from simply one single cause. A variety of causes may interact to develop depression, and some patients might not be able to find any apparent cause for their depression. Major causes of depression could include the following:
Genetic heredity, brain functioning, brain chemical substances or various physiological problems
Abnormalities in brain function: brain scans (MRI- Magnetic Resonance Imaging) reveal that certain brain regions, which are responsible for regulating emotions, thoughts, sleep, eating and behaviours, function abnormally in people with depression.
Chemicals imbalance in the brain: An imbalance of neurotransmitter – a chemical substance which transmits signals across the brain. For example, imbalance of the "happiness hormone", serotonin.
Changes in hormones: Hormones affect brain chemicals that regulate mood. Women are more vulnerable to depression due to hormonal changes during puberty, menstrual cycle, menopause and post-birth giving.
Heredity: Depression can run in family, yet this might not happen all the time, some people living with depression do not have a family history of depression. Research has pointed out that depression is an interaction between genetic and other environmental factors.
Stress and major changes in life are potential environmental factors leading to depression
Study/Work/Family-related stress: When people are under stress, the brain release cortisol. When people are under stress for a long period of time, the prolonged release of cortisol could alter immunity and block transmittance of serotonin, putting people at risk of depression.
Traumatic experiences, loss of loved ones etc. might also cause experience of stress, leading to a depressive episode, or even recurrent depressive episodes.
Psychological changes at puberty or menopause are potential psychological factors leading to depression.
People who tend to experience anxious or negative emotions, such as through exaggerating the negative side of an event, self-blaming, and thinking in a catastrophic way, might have increased risks of depression.
People who tend to avoid unfamiliar people, events or situations and experience mood swing are easier to be in stressful situations, especially when facing stressors.
There are various possible causes for depression. No matter what our personality is, we all have the potential to experience depression in life. Thus, understanding and preventing depression does not limit to some groups of people, it is but relevant to everyone.