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What causes depression?

You may be wondering, what causes depression? The reality is there are so many causes of depression.1

Here, we explain a few of them.

Traumatic events

One of the causes of depression is traumatic life events such as bereavement, separation or divorce, illness, job loss or financial worries – either on their own, or in combination. Sometimes, there can be a ‘downward spiral’ of events that leads to depression, and this could result in triggering it.1

Age-related depression

Some studies have also suggested that you’re more likely to get depression as you get older, and that it’s more common in people who live in difficult social and economic circumstances.1 Having said that, national Census data revealed
one in four young people (24.9%) showed some signs that indicated depression or anxiety.2

Depression and self-esteem

You may be more susceptible to depression if you suffer from low self-esteem or are overly self-critical.1 Low self-esteem may be a personality trait1, but it can also be triggered by things like social media use for example.3

Loneliness and depression

Another of the possible causes of depression is loneliness – such as being cut off from your family and friends – as this can increase your risk. A recent study showed that up to one in five cases of depression among older adults could be prevented by reducing loneliness.4

Alcohol and depression

Alcohol is a depressant as it alters the balance of neurotransmitters (chemical messengers) in the brain that affect your mood, feelings and behaviour.5 Although people with depression may drink alcohol to make themselves feel better in the short term, the effects can quickly wear off and be replaced by anger, anxiety and depression.5

If you are taking antidepressants, alcohol can make your depression worse and increase the side-effects of the medication5 – you should discuss this with your doctor if this applies to you.

Drugs and depression

Regular cannabis use can increase your risk of anxiety or depression. Stimulant drugs such as cocaine and ecstasy can also lead to symptoms of depression. Mixing recreational drugs with antidepressants can be dangerous, or even fatal.6

The NHS provides numerous drug treatment services at locations throughout the UK, which can be found on the NHS website.

Brain injury and depression

Brain injury can be another of the causes of depression. Around half of all survivors of a brain injury experience depression during the first year of recovery. Depression may also develop once an injured person gains an understanding of the impact of their injury and the consequent difficulties that face them in the future.7

Thyroid disease and depression

If your thyroid gland is overactive (hyperthyroidism), you may experience anxiety. If it’s underactive (hypothyroidism), you may experience depression. The former condition can be treated by blocking hormone production, and the latter by giving the missing hormone. Both treatments usually alleviate symptoms.8

Inherited depression

If a close relative (parent or sibling) has had depression, you are two to three times more likely to suffer from it than if you had unaffected relatives. That being said, many people develop depression even with no family history of the condition.9

Pregnancy and depression

Depression during pregnancy (antenatal depression) affects more than one in ten women. Left untreated, the symptoms can worsen and continue after birth (postnatal depression).10

While mood changes – such as being tired and irritable – are common in pregnancy, if you have symptoms such as being tearful, feeling low or hopeless and have lost interest in other people and the world around you, talk to your midwife or GP. They may recommend psychological therapies like cognitive behavioural therapy (CBT) or counselling, or medication like antidepressants, as well as giving valuable advice on self-care.11

If antidepressants are prescribed, your healthcare professional will advise you on the possible risks to your baby associated with taking them during pregnancy.12

Depression after pregnancy (postnatal depression) affects more than one in ten women during the first year after birth. It’s common for women to experience the ‘baby blues’ – where they feel a bit down or tearful. But if these symptoms, or others, such as a lack of energy, sleeping problems, or difficulties looking after yourself or your baby continue, or occur during the first year after having a baby, you may have postnatal depression.10

References

  1. NHS. Causes - Clinical depression. Available at https://www.nhs.uk/mental-health/conditions/depression-in-adults/causes/ [last accessed April 2024]
  2. Office for National Statistics. Young people's well-being measures. Available at https://www.ons.gov.uk/peoplepopulationandcommunity/wellbeing/datasets/youngpeopleswellbeingmeasures [last accessed April 2024]
  3. Taylor-Jackson J, Moustafa AA. The relationships between social media use and factors relating to depression. The Nature of Depression. 2021:171–82. doi: 10.1016/B978-0-12-817676-4.00010-9. Epub 2020 Oct 16. PMCID: PMC7562923. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7562923/ [last accessed April 2024]
  4. National Institute for Health and Care Research. Loneliness is strongly linked to depression among older adults, a long-term study suggests. Available at https://evidence.nihr.ac.uk/alert/loneliness-strongly-linked-depression-older-adults/ [last accessed April 2024]
  5. Mental Health Foundation. Alcohol and mental health. Available at https://www.mentalhealth.org.uk/explore-mental-health/a-z-topics/alcohol-and-mental-health/ [last accessed April 2024]
  6. Mental Health Foundation. Drugs and mental health. Available at https://www.mentalhealth.org.uk/explore-mental-health/a-z-topics/drugs-and-mental-health [last accessed April 2024]
  7. Headway. 10 ways to cope with depression after brain injury. Available at https://www.headway.org.uk/about-brain-injury/individuals/brain-injury-and-me/10-ways-to-cope-with-depression-after-brain-injury/ [last accessed April 2024]
  8. Mayo Clinic. Thyroid disease: Can it affect a person's mood? Available at https://www.mayoclinic.org/diseases-conditions/hyperthyroidism/expert-answers/thyroid-disease/faq-20058228 [last accessed April 2024]
  9. Medline Plus. Depression. Available at https://medlineplus.gov/genetics/condition/depression/#inheritance [last accessed April 2024]
  10. NHS. Overview - Postnatal depression. Available at https://www.nhs.uk/mental-health/conditions/post-natal-depression/overview/ [last accessed April 2024]
  11. NHS. Depression in pregnancy. Available at https://www.nhs.uk/pregnancy/keeping-well/depression/ [last accessed April 2024]
  12. NHS. Cautions - Antidepressants. Available at https://www.nhs.uk/mental-health/talking-therapies-medicine-treatments/medicines-and-psychiatry/antidepressants/considerations [last accessed April 2024]

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UK-NOTPR-1740 | April 2024