Overview of depression
Depression is a common medical condition that is associated with a wide range of emotional, cognitive, and physical symptoms.1 These symptoms have an impact on daily life. People suffering from depression may no longer have control over their moods or feelings, and they tend to feel low almost all the time. Consequently, they may have trouble holding on to their job, keeping up with their studies, and/or maintaining their family life and social contacts.
Depression can strike anyone, but various social and biological factors can increase a person’s risk of developing the disorder. In addition, stressful experiences such as illness, unemployment or bereavement may trigger the condition in some people.
Depression affects people in different ways, but is more than just ‘feeling down’ for a short while. Due to chemical changes in the brain, these symptoms may persist for weeks, months or years. Depression manifests as a combination of three symptom groups: emotional, cognitive and physical.
Emotional symptoms -The emotional symptoms such as sadness, feelings of hopelessness and anxiety are perhaps those traditionally most associated with depression.1
Physical symptoms - Physical symptoms of depression are wide ranging and can involve problems with sleep, appetite and weight, sexual dysfunction and headaches; all of which are highly distressing for patients.1
Cognitive symptoms - Cognitive symptoms affect attention, memory, decision-making and thinking speed, which can have particular negative consequences on daily functioning, affecting work or educational performance.2 Research has also noted that cognitive symptoms, such as trouble concentrating, forgetfulness, or indecisiveness, appear up to 94% of the time during depressive episodes.3 Even in patients thought to be in remission, cognitive symptoms were present in depressed patients for an average of 39−44% of the time during periods of remission.3
At its most serious, depression can lead to suicidal thoughts and self-harm.
Symptoms to watch for:
- Feeling helpless or hopeless
- Feelings of self-loathing
- Loss of energy
- Loss of interest in daily activities
- Appetite or weight changes
- Changes in sleep (too much or too little)
- Problems concentrating
- Recurrent thinking of death
Epidemiology and burden
Depression is found worldwide in people of all age groups and from all social backgrounds, and in both men and women. Depression typically first appears in people aged 20–25 years.4 Estimates of prevalence vary widely, but in most countries 8–12% of people will experience depression during their lifetime.4
The World Health Organization now lists depression as the leading cause of disability worldwide.5 One study found that up to 65% of individuals suffering from depression rated their condition as being severely disabling.6 Despite the large burden of depression individuals and society, however, the fact remains that many people with depression remain untreated.6
Diagnosis and care
People who are concerned that they – or their loved ones – are experiencing symptoms of depression should see their doctor for help and advice. Depression can be diagnosed by a doctor, who will ask about symptoms, daily life and family background. There are numerous assessment scales that can also be used to identify the symptoms, and severity, of depression. Once a diagnosis is made, a combination of different therapies, including medication, counselling, social support, exercise and self-help techniques, is usually recommended.
Depression has no current cure, but treatments for symptoms are available and research continues. Support from friends or a family member is also a very important part of the overall treatment course. Those close to someone with depression are strongly encouraged to help the individual to seek help and to offer positive reinforcement once the initial step of seeking care has taken place.
- American Psychiatric Association. Diagnostic and statistical manual of mental disorders, 5th edition (DSM-5). Washington, D.C.: American Psychiatric Association; 2013.
- Hammar A, Ardal G. Cognitive functioning in major depression--a summary. Front Hum Neurosci. 2009;3:26.
- Conradi H, Ormel J, De Jonge P. Presence of individual (residual) symptoms during depressive episodes and periods of remission: A 3-year prospective study. Psychol Med. 2011;41(6):1165-1174.
- Andrade L, Caraveo-Anduaga JJ, Berglund P, et al. The epidemiology of major depressive episodes: Results from the International Consortium of Psychiatric Epidemiology (ICPE) Surveys. Int J Methods Psychiatr Res 2003;12(1):3–21. Erratum in: Int J Methods Psychiatr Res 2003;12(3):165.
- World Health Organization. Depression fact sheet, 2018. Available at http://www.who.int/mediacentre/factsheets/fs369/en/. Accessed November 2018.
- Kessler R, Aguilar-Gaxiola S, Alonso J, et al. The global burden of mental disorders: An update from the WHO World Mental Health (WMH) Surveys. Epidemiol Psychiatr Soc 2009;18(1):23–33.