Hormone changes during puberty may increase some girls' and boys risk of developing depression. However, temporary mood swings related to fluctuating hormones during puberty are normal — these changes alone don't cause depression.

Dramatic hormonal changes occur during pregnancy, and these can affect mood. Other issues also may increase the risk of developing depression during pregnancy or during attempts to become pregnant.

Many new mothers find themselves sad, angry and irritable and experience crying spells soon after giving birth. These feelings — sometimes called the baby blues — are normal and generally subside within a week or two. But more-serious or long-lasting depressed feelings may indicate postpartum depression.

The risk of depression may increase during the transition to menopause, a stage called perimenopause, when hormone levels may fluctuate erratically. Depression risk may also rise during early menopause or after menopause — both times when oestrogen levels are significantly reduced.

The higher rate of depression in women isn't due to biology alone. Life circumstances and cultural stressors can play a role, too. Although these stressors also occur in men, it's usually at a lower rate than women. The cultural issue with men however, can often be a main factor as reaching out for help can be a challenge.