The World Health Day is observed in Bangladesh as elsewhere across the world on April 7 every year. It marks the founding of World Health Organization (WHO) and aims to draw attention to important health issues facing the world each year. The theme for this year's campaign is depression.

Depression is a common illness worldwide, with more than 300 million people affected. Depression is different from usual mood fluctuations and short-lived emotional responses to challenges in everyday life. Especially when long-lasting and with moderate or severe intensity, depression may become a serious health condition. It can cause the affected person to suffer greatly and function poorly at work, in school and in the family. At its worst, depression can lead to suicide. Close to 800,000 people die due to suicide every year. Suicide is the second leading cause of death for 15 to 29-year-olds.

Although there are known, effective treatments for depression, fewer than half of those affected in the world (in many countries, fewer than 10 percent) receive such treatments. Barriers to effective care include a lack of resources, lack of trained health-care providers, and social stigma associated with mental disorders. Another barrier to effective care is inaccurate assessment. In countries of all income levels, people who are depressed are often not correctly diagnosed, and others who do not have the disorder are too often misdiagnosed and prescribed antidepressants.

The burden of depression and other mental health conditions is on the rise globally. Depending on the number and severity of symptoms, a depressive episode can be categorised as mild, moderate, or severe. An individual with a mild depressive episode will have some difficulty in continuing with ordinary work and social activities, but will probably not cease to function completely. During a severe depressive episode, it is very unlikely that the sufferer will be able to continue with social, work, or domestic activities, except to a very limited extent.

A key distinction is also made between depression in people who have or do not have a history of manic episodes. Both types of depression can be chronic (i.e. over an extended period of time) with relapses, especially if they go untreated.

Recurrent depressive disorder

This disorder involves repeated depressive episodes. During these episodes, the person experiences depressed mood, loss of interest and enjoyment, and reduced energy leading to diminished activity for at least two weeks. Many people with depression also suffer from anxiety symptoms, disturbed sleep and appetite, and may have feelings of guilt or low self-worth, poor concentration and even medically unexplained symptoms.

Bipolar affective disorder

This type of depression typically consists of both manic and depressive episodes separated by periods of normal mood. Manic episodes involve elevated or irritable mood, over-activity, pressure of speech, inflated self-esteem and a decreased need for sleep.

Depression results from a complex interaction of social, psychological and biological factors. People who have gone through adverse life events (unemployment, bereavement, psychological trauma) are more likely to develop depression. Depression can, in turn, lead to more stress and dysfunction, and worsen the affected person's life and the depression itself.

There are interrelationships between depression and physical health. For example, cardiovascular disease can lead to depression and vice versa.

Prevention programmes have been shown to reduce depression. Effective community approaches to prevent depression include school-based programmes to enhance a pattern of positive thinking in children and adolescents. Interventions for parents of children with behavioural problems may reduce parental depressive symptoms and improve outcomes for their children. Exercise programmes for the elderly can also be effective in depression prevention.

There are effective treatments for moderate and severe depression. Health-care providers may offer psychological treatments (such as behavioural activation, cognitive behavioural therapy [CBT], and interpersonal psychotherapy [IPT]) or antidepressant medication (such as selective serotonin reuptake inhibitors [SSRIs] and tricyclic antidepressants [TCAs]). Health-care providers should keep in mind the possible adverse effects associated with antidepressant medication, the ability to deliver either intervention (in terms of expertise, and/or treatment availability), and individual preferences. Different psychological treatment formats for consideration include individual and/or group face-to-face psychological treatments delivered by professionals and supervised lay therapists.

Psychosocial treatments are also effective for mild depression. Antidepressants can be an effective form of treatment for moderate-severe depression but are not the first line of treatment for cases of mild depression. They should not be used for treating depression in children and are not the first line of treatment in adolescents, among whom they should be used with caution.

Ayurveda research shows that many physiological imbalances contribute to depression, anxiety and related conditions. Symptoms of depression and anxiety are triggered by excessive mental and physical stress, or disruptions of natural biological rhythms. According to Ayurveda, psychological problems start when fundamental imbalances develop in the biological intelligence that controls all bodily processes. Some of the popular practices of Ayurveda for depression and anxiety are meditation, pranayama, yoga, and panchakarma.

Ayurveda does not simply match drugs to symptoms, because people can have the same symptoms for different reasons. Just as a headache can have many possible causes, not everyone has depression or anxiety for the same reasons.

Since depression and anxiety can be influenced by many factors, such as diet, digestion, toxin accumulation, stress, exercise levels and daily routine, Ayurveda emphasises re-establishing balance in the body through diet, lifestyle, exercise, and body cleansing, and on the health of the mind, body, and spirit.

What you can do if you think you are depressed:

• Talk to someone you trust, about your feelings.

• Keep up with activities that you used to enjoy previously, when you were well.

• Keep in contact with family and friends.

• Stick to regular eating and sleeping habits.

• Exercise regularly, even if it's just a short walk.

• Avoid or restrict alcohol intake and do not use illicit drugs.

• Seek professional help; remember that with the right help, you can get better.

• If you feel suicidal, contact someone for help immediately.

Depression is one of the priority conditions covered by WHO's Mental Health Gap Action Programme (mhGAP). The Programme aims to help countries increase services for people with mental, neurological and substance use disorders, through care provided by health workers who are not specialists in mental health. The Programme asserts that with proper care, psychosocial assistance and medication, tens of millions of people with mental disorders, including depression, could begin to lead normal lives – even where resources are scarce.

So this year, take some time to spread the word about how you and your neighbours can improve the world's health, on World Health Day!

The writers is Executive Director of Public Health Foundation of Bangladesh (Phfbd) and President of AYUNS. E-mail contact: ayusamir@gmail.com