The exact cause is unknown, anyone can be depressed, some people are more likely to get depression, it can develop for no apparent reason. It is said that a factor is a chemical imbalance in the brain, but this is not fully understood, however an alteration in some chemicals in the brain is thought to be the reason why the anti-depressions work at treating the depression

Depression can occur in stressfully(E.g. abuse, death, loss of job, money worries, break ups Ect)
times in someone’s life this is psychological.

Changes in the chemical in the brain can cause depression, as the hormones tend to go up or down, meaning the person‘s mood would change (which is usually more apparent in women due to menstrual cycles, pregnancy and menopause, childbirth miscarriage Ect.)

Not being social able or physical can also cause depression has the mind is being stimulated.

You are more likely to have depression if, the illness occurs in your family history due to a type of gene called 5-HTT this is inherited and an have an effect on the natural mood changing chemical in your brain called serotonin. Around 20% of people are carrying what is called the “short” version of the 5-HTT, it is these people are more likely to develop depression after a stressful event in their life.

(Please be aware that many people who have a family history of depression never develop the condition, also people who have no family history of depression can still become depressed)

Having to much Alcohol, Drugs,(due to the “come down”) can lead to having depression also some prescription medication can have a side affect of depression.