What’s the connection between poor sleep, low BDNF levels and depression?
We depend on our brains to adapt to social and physical stressors. Yet, their ability to adapt isn’t infinite. Once we reach a breaking point, we quickly become more susceptible to stress-related mental disorders like major depression.
Yesterday I discussed how intense and exhausting physical exercise, such as sprinting until the body’s demand for oxygen overwhelms its supply, quickly raises BDNF.
However, continuing to push beyond our natural limitations leads to fatigue and plummeting BDNF levels.
At that point, it’s time to rejuvenate BDNF with healthy food and restful sleep, but what if our fatigue and stress make sleep difficult?
How Sleep Quality Affects BDNF Levels and Depression
Last month, I posted on the necessity of getting adequate deep sleep.
Psychiatric researchers at Switzerland’s University of Basel examined BDNF levels in two groups of participants. One enjoyed undisturbed sleep. The other struggled to sleep through the night.
Comparing the two groups, they found “significantly reduced” BDNF levels among the insomniacs. They also discovered a significant correlation between BDNF levels and the degree of insomnia.
In other words, the less sleep a participant had, the lower their brain’s ability to grow new connections!
They also noted that participants reporting symptoms of fatigue had significantly lower levels of BDNF than those getting restful sleep.
The Swiss researchers concluded,”… [S]leep disturbances may result in higher stress vulnerability, reduced environmental adaptation and cognitive impairment.”
Research from the University of Heidelberg’s Central Institute of Mental Health affirms the findings that lower BDNF levels combined with excessive stress create a double whammy of negative consequences for our brains.
Stressful events and chronic stress alike disrupt the sleep imperative for our memory formation and cognitive function. Our brains can’t learn from and adapt to the stress that’s keeping us awake.
The resulting mental confusion leaves us less likely to identify and eliminate the source of the problem. The longer it continues, the greater our risk of slipping into a state of chronic stress – and from there, into full-fledged depression.
Chronic Stress, BDNF Levels and Major Depression
Both physical and mental short-term stress increases the brain’s BDNF production and neuroplasticity. Long-term unresolved chronic stress is a different story. It leads to higher levels of cortisol, which can trigger inflammation. Inflammation can, in turn, disturb our sleep.
- inadequate sleep
- depleted BDNF
- major depression
Finding a way to break this nightmarish cycle is challenging because real physiological factors fuel the inability to sleep restfully through the night.
How Much Restful Sleep Counteracts Low BDNF Levels and Depression?
How much sleep does it take to rejuvenate us when we’re under chronic stress?
A convincing amount of research sets the recommended minimum of at least seven hours of restful sleep a night.
This 2019 study from Tokyo, Japan’s Nihon University School of Medicine, enrolled 577 nurses. Its goal was to achieve a better understanding of the connection between BDNF concentration and poor sleep.
The results? The nurses sleeping less than six hours a night had significantly lower BDNF.
But for anyone in the throes of depression, getting anything close to even six hours of restful sleep can be impossible. However, there IS hope.
Stress, inflammation, poor sleep, low BDNF levels and depression are our body’s way of telling us something is seriously wrong. And that’s when it’s time to stop and ask, “Why am I depressed?” and, if necessary, to seek professional help.