Pixabay Images

Pixabay Images

Depression is sometimes categorised as a mental, rather than a physical illness – as though somehow mental health is different from physical health. But the brain is not a magical black box inside your head. It is an organ, just like the heart or lungs, made up of cells and supplied with blood.

These brain cells grow and develop, making contact with other brain cells to communicate with one another. They control all of our behaviour, emotions and actions. And sometimes they go wrong, leading to illnesses like depression.

Depression does run in families, which could mean depression is genetic, an inherited condition. But families don’t just share genes – they also experience a similar environment. So how can we separate genetic influences on depression from environmental factors?

– Sarah Bailey

Read more: The Conversation: Why isn’t there a gene for depression?