What causes depression?
Depression is a complex mental illness, so there is no single cause. However, there are a number of factors that can play a role in depression, such as traumatic life experiences, hormonal and chemical changes in the body, social or economic pressures, and genetics (family history). You are also more likely to experience depression as you get older.
Depression is a common illness and can be triggered by different things. People experience depression in different ways, and sometimes without a clear trigger. You are not causing your depression.
Some common medications used to treat chronic conditions have been linked with depression according to recent research. Although no single medication has been shown to directly cause depression, some prescribed medications (steroids, anticonvulsants, antipsychotics, hormonal drugs, stimulants, statins and PPIs) have listed depression as a possible side effect.
Long term illnesses or life threatening conditions can trigger depressive episodes, or increase your risk of depression. This can be because of the condition itself altering the chemistry of your brain or body, such as head injuries, thyroid conditions, or certain cancers. For others, living with a long-term illness can be stressful and exhausting, and can lead to low mood and a loss of interest in everyday activities.
Pregnancy and childbirth are major life events that are often stressful, and can put women at a higher risk of depression. Hormonal changes, being responsible for a newborn baby, and the lifestyle changes that come along with pregnancy and childcare are common causes of postnatal depression.
Family history (genetics)
Genetics may be the cause of depression in some cases, as it is more common in people who have blood relatives with the condition. While most people with a mental illness do not have a family member with the same illness, some studies suggest that having a family member with certain depressive disorders could increase your risk. Currently, very little is known about the genes that may be involved in depression.
People with certain personality traits, like low self esteem, introversion, or other insecurities, may be more vulnerable to depressive symptoms. These personality traits or dispositions could run in the family genetically, or they could be learnt behaviour through life experiences.
Stress from different life events like financial issues, loss of a loved one, work-related pressures or relationship issues, can be a factor that causes depression. Usually, stress will be a short-term feeling that disappears when you’ve resolved what’s causing it.
Alcohol and Drugs
Some people turn to substances, such as alcohol and other recreational drugs, to help them cope with pressures in their lives. Others may find that these substances can trigger depressive episodes, even when they do not feel depressed sober.
Alcohol changes how you think and react toward situations, which is why some people turn to drinking to help them deal with stressful or traumatic events. However, alcohol affects the chemistry of your brain, which can make you more prone to depressive thoughts or low mood.
Recreational drug use (like cannabis) can also lead to feeling depressed. Cannabis is often used recreationally to relax, but some people find that it can trigger anxiety or depressive thoughts.
Alcohol or drug-induced depression can happen even with casual use: you do not need to be addicted to a substance for it to cause depressive episodes. However, dependencies or addictions to substances can increase your risk of depression. If you are struggling with alcohol induced depression or drug abuse, you should speak to your local GP for support.