what is depression?

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According to the World Health Organisation, Depression is the leading cause of disability worldwide and 300 million people have it. Go and see your GP if you think you have depression, in general people often wait a long time before seeking treatment. The NHS thinks only 70% of depression is picked up by healthcare professionals. 

Depression often goes alongside anxiety, but can also come before or after depression. This is something that our members often describe.

Depression is a biological disease that interacts with social factors, our psychology and thoughts to have a devastating effect on people's lives. Depression and anxiety are on one level all about a chronic stress response in the body which is triggered repeatedly rather than short term stress that is a normal part of everyday life and this manifests itself in physical symptoms, thoughts and feelings.

 "It's a biochemical disorder with a genetic component, and early experience influences where somebody can't appreciate sunsets" Robert Sapolsky, Professor of Biology, Neurology and Neurological Sciences, Stanford University.

"Depression is a cover version by a downbeat emo band, and anxiety is a cover version by a screaming heavy metal group, but the underlying sheet music is the same. They've not identical, but they are twinned" Johann Hari. 

It is a mix of symptoms that are often difficult to pin down, but can include

  • anhedonia (lack of enjoyment of things, particularly ones you should enjoy)
  • apathy
  • guilt
  • grief
  • obsessive worries
  • psychomotor slowing (physical difficulty to do everyday tasks such as brushing your teeth)
  • problems sleeping
  • hopelessness
  • eating little or eating too much
  • pain

Unhelpful language around depression

Because depression is a word used to mean sadness and other similar words, there is a real stigma around people seeking help and even talking about it to their partners, family, friends and workplaces.

Until the 1920s even though it was being studied a lot, it was called Melancholia and the American Psychiatric Association eventually went for depression as a term which included variants such as depressive reaction, depressive neurosis with detours along the idea of 'endogenous' and 'exogenous' depression before finally settling at today's terms major depressive disorder, depression and clinical depression. A similar thing happened with bipolar disorder which was called manic depression (and variants). Even today many people repeat unhelpful old names and terms. 

Some feel that clinical depression is an unhelpful term as it leads some people to believe that they don't have it and not seek help. You should always talks to a GP as soon as possible.

Risk factors 

Around 40% of the susceptability of depression and anxiety is believed to be down to genetics. This means that it isn't inevitable and means someone will get it if social and environmental factors are triggered. 

  • isolation and loneliness
  • bereavement
  • workplace stress
  • other major life events such as university, losing a job, traumatic event
  • substance abuse
  • lack of control
  • lack of meaningful activies such as work 
  • sleeping problems or working night shifts


Originally in the 1950s it was thought that a neurotransmitter called Noradrenaline had a lot to do with depression as medications related to this in early antidepressants. Over time it was also discovered that Dopamine had a role and particularly Serotonin. A particular gene called SLC6A4 had a vast number of research studies and papers focussed on it was heavily associated with the genetic risk of developing depression if stress and traumatic events triggered it and how likely it was to return. The protein that is encoded by SLC6A4 is today now much better known as the serotonin transporter, or SERT, or 5-HTT. A bad analogy is that the neurotransmitters are a bit like oil lubcricating the neuron connections in the brain allowing better running. These neurotransmitters were the basis of where all five classes of 'antidepressants' originated from. The monoamine theory of depression is that these three neurotransmitters (sometimes quoted as two) have something to do with depression. One of the puzzles is why SSRIs do not work straight away and this is the basis of a lot of research, one leading theory is that the binding sites the neurotransmitters work on get gummed up in an area of cell membranes called lipid rafts and over time are moved out where they can work better.

Postnatal depression

Postnatal depression is not the 'baby blues', which can last up to two weeks after giving birth and goes and affects such a large percentage of women (up to 80%) that it's considered 'normal'. Postnatal depression often starts 2 to 8 weeks after giving birth, but can not be picked up or emerge later and the NHS quotes this as a year, although some believe it may even be 2 years. Postnatal depression affects 1 in 10 women. In the past it went vastly underdiagnosed. 

The NHS website has a lot of resources for postnatal depression here. There are support groups in Sheffield through Light. In Sheffield there is a small dedicated team of midwives that deal with mental health after childbirth. Anyone with anxiety, depression, or low mood after childbirth is welcome to attend NPS self help groups. 

The levels of estrogen and progesterone and their ratios and particularly sudden changes are intimately linked to mental health. For anxiety, depression and low mood the focus is often on short term stress response or the HPA axis. However the hypothalamus which is at the bottom of the limbic system deep in the brain , which is often associated with emotions, also controls the HPG axis linked to reproduction and hormones. When the HPG axis in women is no longer regulated, the menopause results, which varies but can lead to some very severe symptoms and difficulties with mental health.

Protective Factors

The idea of protective factors has received a lot of interest recently due to the BBC documentary Alastair Campbell: Depression and Me where he talks about a jar that can break and extra parts that can be added on top. This is a really good way of seeing things that can protect against depression returning or make it slightly more manageable. Protective factors can be very small things such as things you enjoy. Major protective factors are exercise, a support network of good friends/family and coping strategies.