Recent quotes:

Disrupted circadian rhythms may drive anxiety and exacerbate brain disorders

"The studies presented today help deepen our understanding of why sleep is disrupted in so many patients," said press conference moderator Clifford Saper, MD, Ph.D., of Harvard Medical School, who's work focuses on integrated functions maintained by hypothalamus which includes the regulation of wake-sleep cycles. "They also suggest that sleep-focused therapies, such as treatments to regulate circadian rhythms, may be beneficial in the prevention or treatment of a vast array of diseases, including Alzheimer's disease and anxiety disorder and furthermore emphasize the critical need of good sleep for everyone's health."

In depression the brain region for stress control is larger -- ScienceDaily

So far, it is known that people more predisposed to depression show a dysregulation of the endogenous stress response system, otherwise known as the hypothalamic-pituitary-adrenal axis (HPA axis), which is normally triggered when we are faced with a stressful situation. This response increases the amount of cortisol, providing the body with more energy when faced with a potential threat or challenge. Once the challenging situation has passed, several control mechanisms in the HPA axis normally ensure the system returns to a balanced state. In people who suffer with depressive disorder or who are more predisposed, this is not the case. Instead, a malfunction of the feedback mechanism results in a stress response operating at full throttle, even when there is no apparent stressful situation. Until now, the underlying reason for this hyperactive stress response system and the role of the hypothalamus as its overall control unit has remained unclear.

Brain activity linked to stress changes chemical codes: Findings may be relevant to other disorders, from autism to PTSD -- ScienceDaily

In the new findings, the researchers studied the change in neurotransmitter identity when rats, which are nocturnal, are exposed to long day lengths. This exposure led to elevated activity of paraventricular (PaVN) neurons in the hypothalamus and by consequence a loss in their expression of dopamine, a neurotransmitter that is linked with many aspects of normal behavior. When the researchers suppressed the elevation of activity that resulted from the long-day exposure, exclusively in the PaVN neurons, they blocked the transmitter switch that would have occurred under these normal light conditions.