Is Depression Really On The Rise? If So, Why?

If you look at depression statistics spread over several years, a very worrying trend becomes immediately apparent. Cases of depression begin to rise extremely sharply in around 2005, and continue to escalate at an alarming pace. Should the problem continue in this vein, it seems that everyone in the world will before long be suffering from depression, or some form of anxiety disorder. Not good. Science and psychiatry are, it seems, a little divided on the issue. Various theories as to the source of the problem have been put forward, but there is as yet no real consensus. Some do not even believe that the problem is real, attributing the statistical rise to diagnostic improvements and a change in culture. So what, if anything, is going on? What do people think is behind this problem?

The Internet

One of the most common theories holds that the rise in internet usage has - directly or indirectly - brought a host of mental health problems in its wake. The theorized abilities of the internet to change our brains and trigger neurosis are multiform, and a whole book could be written on the phenomenon. Briefly, however, here are some of the more common points made:

The internet causes addiction. Many scientists, particularly in Asia (where it's a big problem) believe that the dopamine surge caused by receiving information, validation, and 'rewards' through gameplay via the internet can cause pathological usage and addiction. This naturally alters the brain's chemistry, predisposing many heavy internet users to anxieties and depressive states. It's an as-yet little understood phenomenon, but people are taking it seriously - so much so that many health insurers are adding internet addiction to the list of things they cover.
The internet reduces our 'mental downtime'. Instead of relaxing when we get home, we log immediately into the internet, over-stimulating our brains with both work and leisure, and effectively preventing them from getting the vital rest they need to start processing the emotions and experiences of the day. This ultimately leads to mental health problems like depression.
The internet feeds us a lot of depressing news, and makes us periodically angry (more on that later).
The internet (and social media in particular) puts us under subliminal pressure to achieve a standardized 'perfection' - showing us the carefully tailored social media streams of our friends, which appear to show a 'perfect' life to which we cannot possibly live up. This is all of course heavily edited and a 'glossy' version of the actual (more mundane) truth, but it nonetheless causes a good deal of insecurity and feelings of worthlessness.
Urbanization

The world has reached an unprecedented landmark. By 2017, it's thought that the majority of people will be living in urban areas. In the past, the majority of people worldwide have always lived in small rural communities - with urban centres making up a significant population proportion, but never greater than the whole sum of humanity. Now, however, the cities are expanding and more people are moving to them. This, it is thought, increases depression risk in a number of ways:

Lack of access to 'green spaces'. It's by now well known that our mental health is significantly boosted by time spent outdoors, preferably in green, leafy spaces. The urban environment and lifestyle makes doing this much harder - and even those who regularly enjoy parks may lack the kind of distraction-free experience gained by those in the countryside, due to the presence of lots of other people.
Anonymity. In small, rural communities, people are known to one another, and are often cared for by the community should things go wrong. While many urban communities are very cohesive, it is nonetheless more common to experience 'anonymity' in cities. When nobody really knows who you are, and you lack a sense of 'place', 'tribe', or general human connection, it is easy to succumb to feelings of worthlessness and depression.
Stress. Everyday urban life tends to be more 'high powered' and stressful than rural life. Negotiating traffic, constant noise, enhanced crime rates, busy jobs... all of these enhance an urban-dweller's risk of stress, which in turn raises their risk of developing depression.
Lifestyle

It's no secret that we're becoming increasingly sedentary, and eating an increasingly poor diet. Without good cardiovascular health (as is bestowed by regular exercise), our brains are less able to receive nourishment from the blood. And without the right kind of diet, that nourishment which they do receive is sub-par and unable to fulfil all of the brain's requirements to keep our mental and emotional health at a reasonable equilibrium. It's thought that dietary and general lifestyle improvements could make an enormous difference to the global mental health situation.

Fear

There has been much talk recently about the 'politics of fear'. Media and political campaigns designed to elicit sales and votes by scaremongering have become much more common in recent years, and the stress, hatred, and anger provoked by these can have an extremely negative effect on mental health. What is more, the internet provides us with access to negative news stories in unprecedented amounts. All of this serves to make us more anxious, and renders our ruminations rather more negative than would otherwise be the case.

Statistics

Some, however, believe that all of the above is simply an illusion, and that the real problem is not a problem at all. In recent years, we have become far better at accepting, seeking help for, and diagnosing mental health problems - all over the world. Perhaps we've always been this depressed - it's just that we're more self-aware about it now...