The Balanced Brain: The Science of Mental Health

Nord, a professor of neuroscience at the University of Cambridge, debuts with an invigorating examination of “how the brain constructs your mental health.” Contending that “your brain’s biology, and its close relationship with your physical body, creates, sustains and protects your mental state,” Nord explains that some scientists think poor mental health stems from a “miscalibrated” dopamine system that provides only modest boosts in mood for “positive events” yet “overresponds” to negative ones. Expounding on the effects of various treatments and activities on the brain, Nord discusses how exercise prompts the release of “pleasure-related endogenous opioids” and how antidepressants increase activity in the amygdala (a brain region involved in emotional processing and interpretation) in response to positive stimuli while dampening responses to negative stimuli. The research fascinates—she reports on studies that found depressed subjects were more likely to view ambiguous facial expressions as angry, highlighting the complex interplay between mood and how the brain interprets the world—while correcting oversimplified scientific misconceptions. For instance, Nord explains that contrary to the common belief that serotonin deficits in the brain cause depression, studies have found that deliberately lowering serotonin levels doesn’t reliably produce low mood in subjects, suggesting depression’s origins are more complicated than the effects of one neurotransmitter. The result is a superior volume on the biological underpinnings of mental health. (Jan.)