(adsbygoogle = window.adsbygoogle || []).push({}); Roughly 20% of the developed world population suffers from a mental disorder of some sort. If the human brain has been evolving for the last ~200,000 years, wouldn't you expect the number to be a lot lower? The prevalence of mental disorders could be due to many things, but it seems as if that they aren't disappearing with evolutional advancements. Could they provide an aid to the individual that is not completely obvious? Could this benefit be translated into one that is beneficial to society?

For example something as crippling as depression and neuroticism can allow the individual to become more self-aware, allowing them to improve on themselves.

Schizophrenia: higher resistance to shock, increased resistance to physiological substances, and probably many other benefits.

Still not sold?
Psychopathy: psychopaths are assertive, psychopaths don’t procrastinate, psychopaths tend to focus on the positive, psychopaths don’t take matters personally, psychopaths don't get upset if things go wrong, psychopaths work well under stress.

All of these can be seen as evolutionary benefits, but could these benefits translate into societal benefits? For example psychopaths are often in executive positions, which they preform well in because of their ability to make decisions without second-guessing themselves or worrying about the outreaching effect it might have on other people.

To answer your first question, about the percentage being lower, you would be correct. It should be a lot lower if natural selection still existed. But it doesn't.

I understand your point, and I'm sure many mental disorders have benefits that no one thinks of or realizes, however the general idea is that the downsides outweigh the upsides. To answer the question of why haven't we evolved past them. In my opinion, it is simply genetic defects, which will always plague humanity. They are called defects because normally we have evolved past them, but for one reason or another, the affected person didn't. The other obvious answer is extreme trauma, which can lead to PTSD and depression.

After reading the thread title I thought you may be a little crazy but after reading the whole thread it makes sense.

I was first diagnosed with depression at 18/19, things get pretty shitty but thats for another time. A few months after I was 'better' I did notice things about myself and I felt different about myself.

20% seems around right because look at the stresses and strains of the modern world.

my autism lets me not realise all the hurtful things said to me

Natural selection doesn't apply as much to humans anymore now that we have so many medical and technological advancements... but it still exists.

My logic is that mental illness should reduce the chance of reproductive success, unless there might be other benefits that might help the individual. But as other people said there are definitely other factors coming into play -- it could just be a mistake of evolution or due to problems that we only now face in society.

No....

Range of mental disorders which have an negative impact on individual or society as a whole. Some of the best creative works known to man have been born out of suffering from mental health condition.
Minor benefit for society however the cost out weights the benefit for every great piece of art created somebody can become overwhelmed by suicidal thoughts. Questions if current society has helped create an increase in mental health conditions or living longer means the conditions are seen.

On the subject of psychopaths been loads studies into them. Most famous one which I can't remember the name had some interesting results.
Psychopaths lack any sense which holds us back from hurting others and various feelings. Result they are simply some of the best killers able to executive rationale train of thought .
Group tried to understand what rules they had in place and found they had nothing like most normal people.
Couple tried to teach them how to become more human, instead the psychopaths became even more effective at faking being human and caring. Empathy they lack it however when they become good at faking empathy they are very deadly. We believe they have a switch which allows them to turn it on and off.

Team could not control the test group or improve them so they could rejoin society all they did was make better psychopaths. Lead scientist behind the project found it horrible what she created was even more deadly predators. Combo of lacking fear with empathy but you can fake it better compared to the average person makes you one hell of a killer.
Key issue is impossible to control somebody so gaining that benefit is impossible...

Dexter the TV series did look that concept showed something we found to be true which was genetics markers plus violent history in the early years can turn people into criminals.

Some people have issues and can only do a few things but the few they can they do amazingly i work with 450 + peopple in busy envienvirmoeant we have a good amount of peopple with issues who have been sectioned we know how and what they are good at at work and cater for there needs they dont have any problem and it keeps them busy as if sitting in home board with nothing but there thoughts wich isnt always good

I don't think the positives outweigh the negatives with mental disorders.