Much of Science!™ is the process of discovering the total bullshitiness of last century’s Science! From Scientific American:
The general idea is that a deficiency of certain neurotransmitters (chemical messengers) at synapses, or tiny gaps, between neurons interferes with the transmission of nerve impulses, causing or contributing to depression. One of these neurotransmitters, serotonin, has attracted the most attention, but many others, including norepinephrine and dopamine, have also been granted supporting roles in the story.
Much of the general public seems to have accepted the chemical imbalance hypothesis uncritically. For example, in a 2007 survey of 262 undergraduates, psychologist Christopher M. France of Cleveland State University and his colleagues found that 84.7 percent of participants found it “likely” that chemical imbalances cause depression.
Of course if it’s not chemicals, maybe it’s “structure”.
A possible clue lies in brain structures. Imaging studies have revealed that certain brain areas differ in size between depressed and mentally healthy individuals. For example, the amygdala, which responds to the emotional significance of events, tends to be smaller in depressed people than in those without the disorder.
Maybe, but depression isn’t usually a permanent condition. And the brain doesn’t, as far as I know, undergo macroscopic restructuring during adulthood. And of course there’s the correlation/causation issue again.
Findings also point to a crucial role for psychosocial factors such as stress, especially when it arises from a loss of someone close to you or a failure to meet a major life goal. When someone is under a good deal of stress, a hormone called cortisol is released into the bloodstream by the adrenal glands.
Findings, eh? If you needed Science! to point you in that direction… Squeezing cortisol into the picture makes this seem like progress, but then the trigger for its release throws us right back into the subjective realm of the mind. Speaking of which, the article concludes:
…we must integrate what we know at multiple scales, from molecules to the mind to the world we live in.
Mind…now we have a problem. The mind is impervious to objective study.