Serotonin: a polish and a theory

Dr lacquer sell a polish called serotonin. It's part of their hormones series. When I discovered this I had to have it lol.
I love this brand in general, it appeals to my (not so) hidden nerd. I enjoy the science link and the puns in many of the titles. Plus the logo's adorable :p lol.
Asides from all that one of my weirder set of possessions is a collection of serotonin themed objects. Earrings and necklaces and such. Magnets. So it only seemed right to add a polish lol.

Next question I guess would be why? Lol. Well one of the most popular suggestions for the cause of depression is the serotonin hypothesis. This essentially states that depression is caused by levels of serotonin in the brain being too low. Serotonin itself is a  neurotransmitter, a substance that moves around the brain carrying messages, and is responsible for a huge number of different things. It's been suggested that there's a correlation between reduced serotonin levels and depression.  It's possible that low levels cause the symptoms of depression. It's possible depression causes low levels of serotonin. It's also possible that another factor causes both low serotonin levels and depression.
In the weird way of psychology and science in general the theory popped up in a round about way when an observation in an entirely separate area of medicine led to a possible treatment for depression, which seemed to work. From here a theory was suggested for why the medication worked (welcome serotonin) and reversed. If increasing serotonin helps depression then low levels could cause it. The  hypothesis has been researched of course, adapted, had bits bolted on bits taken offand given rise to other newer ideas.

But I'm rambling and I didn't mean this to turn into a psychology lesson. So back to the point. The reason I care in the first place is simple. I've had mental health problems for several years and since very early on I've wanted to know why. Not really in a self pitying 'why me' kinda way (though I have my moments of self pity no doubt lol). I just like to know things, I like to make sense of things. And there is no real logic to mental illness in many cases. I mean for me personally there was no massive trauma that triggered it, no deprived or abusive childhood. No bullying. No particular struggles at school. No underlying physical condition. No massive upheaval or make life events that precipitated it. It just was. And if for a long time before it actually was it kinda was. Depression was not that dissimilar to the usual state of my brain, just that the levels had been fiddled with. The volume had been turned way up and muted at the same time. Depression lives a good paradox.
Anyway point being, with no obvious psychological causes I set out to find out as much about the physical side of mental health as I could. And whilst i won't bore you with it all here, it's seriously fascinating. I still don't have the answers I want of course, because nobody does. But I do have a lot more information and knowledge and that's never a bad thing. The serotonin hypothesis has several holes, and there are more well rounded ones being explored but serotonin is some sort of symbol or talisman for me. It represents the biology, the search for answers and the fact that maybe I'm not just being pathetic.
Oh and the polish is pretty. And thermal :p.