Originally posted by Schnitzelfisch
From the top of my head it's that people in general start going out more (after winter), interacting more, are happy outside in the sun. When lonely people see this, they tend to become even more lonely and depresse ("Why can everyone be happy but me??").
This might not be 100% accurate, I didn't look into it deeply; I'm sure you can find some studies online though if you're interested in the subject.
Greetings from Moscow, SF! 
Maybe you were referring to this article from Google's top, maybe not. But the point is that there are different reasons for different people. The 'pressure to be happy' you've mentioned is one of them, the rapid weather change (faster than in autumn) and allergies blamed there are also significant (I had allergy in the past that peaked in July-August, maybe it's still having impact on me, who knows). Another reason might be that some people hate light - that's my case for one. It's person-dependent.
Back to the topic, has anyone here thought on whether lyrics' effect withers as time passes and they're learnt by heart or it adds up with time like with self-suggestion phrases? I used to think that keeping the playlist fairly constant would reduce the distracting effect of lyrics. But once upon a time it dawned on me that my playlist was sending me negative vibes.
I'm a clinical case here as I'm a beginning headbanger 
Ironically, I had hardly ever listened to music on purpose before 'going a micro-PLO pro' last June. Metal and rock were preferred kinds of music in my former math environment, but I was hardly into music at all, only listened to it to socialise. But when I was going to start grinding, I recalled that my brother always had metal on while driving (despite hardly listening to it outside the car any longer), had said it helped him to concentrate on the road. So I just picked some of the CDs left from his youth, copied them onto the laptop and started putting them on during sessions.
Whether it helped me to concentrate is debatable: I sometimes forgot to put it on for like 15 minutes into the session (4-6-tabling), then suddenly noticed that I was bored, but didn't feel bad about not hurrying to put it on either: the table decisions were absorbing me. I had distractions when most favourite lyrics were sung and echoed them, but those were for only a few seconds and mostly when I was not in a hand. I didn't manage to run a full-blown lossrate difference test, but I didn't feel way differently in general.
Then, when I entered a slump bigger than before, I started blaming that on negative lyrics (esp Korn's 
) and gradually (I spend little time looking for extra songs) replacing them by positive power metal anthems, removing topics one by one: reproduction, sadomaso, hatred for parents, tyranny - all that probably tilted me or was dangerous to think about while grinding.
My playlist got separated into grind and non-grind parts (I still have to endure the soul pains when I'm not playing, hiding them would be even worse). The grindlist consisted mostly of inspirational power ballads whose strong beat, like on a march, made me feel like a fearless warrior. I found it bad to bring my lame real life to the poker office.
But I didn't notice a lossrate change after that either, maybe because the messages I was trying to send to my subconscious didn't match the reailty. It all went worse until I quit grinding after 170K hands :f_pleased:, ironically, because of concentration issues, but arising from poor sleep. I'm still enjoying the process of seeking new bands and have metal on sometimes when surfing (when I don't forget to do so like right now 
).
So the bottom line of my case study is:
1. Testing is great, but I should have been more observant and keeped thorough records when doing it.
2. I think I should have been more careful about what messages the things surrounding me conveyed and started using the technique of passing subliminal audiomessages through the grindlist earlier.
My respect goes to you all, esp those who can grind without music. May the force be with you!
