Over the past decade, depression has received significant coverage in mainstream media with many high-profile organisations, such as Beyond Blue and the Black Dog Institute as good examples, not to mention a number of prominent individuals publicly declaring their own demons in this very common area of mental health.

It is estimated that around 7% of people living in the modern world will experience an episode of major depression on a yearly basis. Depression is defined as five or more of the following symptoms persisting for more than two weeks

1) A depressed mood with the loss of pleasure in normally pleasurable activities

2) Abnormal weight loss or weight gain

3) Poor sleep and, in particular, early morning wakening, but this may also include too much or too little sleep

4) Physical agitation or slowness

5) Fatigue

6) Feelings of guilt/worthlessness or hopelessness

7) Lack of focus and at its extreme, thoughts of death and suicidal thoughts.

Thankfully, depression is no longer seen as a purely psychological illness or as a sign of weakness or poor character; a condition that the person should toughen up and pull themselves out from.

Probably the most accepted theory is that depression is a disorder of brain chemicals-typically a reduction in the mood chemical, serotonin. This hypothesis is strengthened by the strong observation that serotonin altering pharmaceutical drugs are the mainstay of medical therapy for depression. Although this is probably the case, there are some researchers in the area who dispute this and until we have better methods to assess brain function and neurotransmitter levels within the brain, this explanation will have to suffice.

Interestingly, recent work has suggested that depression could also be a gut disorder. 90% of our serotonin is produced by gut bacteria and it may be that a pathologic gut microbiome may not be producing enough serotonin to maintain a balanced, non-depressed state.

Recent work has also strengthened the notion that depression may have serious systemic health effects through a number of mechanisms.

A recently published study in the Canadian Medical Association Journal followed 3410 adults from Canada over a 60 year period. This examined the death risk associated with depression in both males and females, average age 49 years at study entry. This very long study had three distinct periods each around 20 years and found that in males the increased death risk was present through each period but was very prominent in females for the most recent period from the 1990s and onwards. This rose to a 50% increase death risk for women during that period.

Equally disturbing was the findings that the younger the diagnosis was made, the much higher the death risk. There are three possible explanations for the higher death risk associated with a diagnosis of depression.

1) Depression leads to reduced motivation to follow healthy lifestyle principles with a poorer diet, reduced motivation to exercise and a much higher rate of substance abuse.

2) Depression leads to an increase in stress related hormones and a reduction in the variety of “happy chemicals”- both conditions being associated with chronic illnesses.

3) Depression is the leading cause of suicide

Although it is important to make the distinction (a distinction that is often blurred) between depression and grief or loss, there is no doubt that depression is not just a serious mental health issue but significantly increases the risk for a variety of (at times) lethal physical diseases.

As with all conditions, the best management is prevention or at least early detection and intervention. But, this is not possible unless you seek help. Remember, symptoms are nature’s tickets into the medical system and if you have any of the symptoms mentioned above, seek help early. It may just save your life.