This morning I've heard this talk on Ted.com:
The presenter is discussing an iPhone app used to track happiness, and seems to draw a conclusion that "mind wandering" is a related to much unhappiness, and that mind wandering is pervasive in 47% of his respondents. He also suggests that "being in the present" is tied to feeling happier.
His methods and graphs aside, I'm interested in this question:
Is "mind wandering" a thought pattern that arises naturally as a cognitive process, regardless of the brain biology? Or is it a biological marker, indicating the change of state of the persons biological homeostatic state? By Biological homeostatic state I mean neurotransmitter levels/binding, endocrine system state, etc.
For example, if a person is intoxicated with alcohol, then the person cannot help, but feel different, because of the foreign substance. I'm interested if there's any research indicating if different mental states, for example mind wandering, are caused by something that changes within the brain?
Because mind wandering is a rather vague subject, here's another thought process that has a very definitive effect on happiness: suicidal ideation. If a person is thinking of suicide, there's at least a chance that the person will follow through with the ideation, and from the quotes below, it seems that at least some victims were studied
Deceased suicidal and otherwise depressed patients have had more 5-HT2A receptors than normal patients. These findings suggest that post-synaptic 5-HT2A overdensity is involved in the pathogenesis of depression.
And another one:
Many human polymorphisms have been identified influencing the expression of 5-HT2C. Significant correlations are suggested, specifically in relation to psychiatric disorders such as depression, OCD, and anxiety-related conditions. Polymorphisms also correlate with susceptibility to a number of conditions including drug abuse and obesity.
Reading this, it seems plausible that suicidal ideation, as a thought process, is at least partially related to the Serotonin(5HT) receptors 2A and 2C. As such, is it plausible to say that suicidal ideation is a biological marker of depression, just as mind wandering may be a biological marker of unhappiness?
Thank you for your input!