The Takeaway: New research shows that anxiety is marked by dysfunction of our mitochondria – the energy producers of our cells. According to the new study, “chronic stress may critically affect cellular energy metabolism.” This raises the question of whether anxiety comes with lowered performance of your muscle and brain cells for example, which like other energy-demanding cells require efficient mitochondria. Dysfunctional mitochondria might also play a role in depression. Managing your stress levels may be important to keeping your mitochondria healthy – along with exercise training and even intermittent fasting, which can prompt cells to regenerate their mitochondria!
We’ve all experienced anxiety at some point: heart racing, sweating, racing or unwanted thoughts. Many of us attribute anxiety to an impending high stakes experience, whether that be for an exam, a musical performance or a game.
While the (temporary) state of anxiety may actually lead to positive outcomes (has anxiety for an upcoming test or performance or game ever motivated you to study/practice harder and ultimately to perform better?), overwhelming anxiety has clear negative impacts on our health and quality of life. Consistent anxiety that is out of proportion with the triggering event is known as anxiety disorder, which, according to the Anxiety and Depression Society of America, impacts 40% of the American population, making this mental illness the most prevalent of all mental disorders in the US.
How much do we really know about anxiety?
We know that anxiety disorders develop from a complex web of factors including genetics, stressful life events and family history. We also know that drugs such as selective serotonin-reuptake inhibitors (SSRIs; such as Lexapro, Prozac, Zoloft, etc.) are fairly effective at treating generalized anxiety disorder. Undergoing cognitive behavioral therapy, mediated by a trained therapist, is also an effective way for many people to manage an anxiety disorder. There is also evidence that alternative treatments, such as yoga and exercise, may relieve the symptoms of anxiety disorders.
But what does anxiety actually look like at the molecular level, and how could we treat it there? What is actually happening in our cells—particularly in our cell’s energy production centers—when we experience a panic attack or chronic anxiety? And, if we gain insights into the cellular basis of anxiety, might that help us better treat the millions who suffer from anxiety disorders?
Investigating anxiety with multi-omics and cross-species approaches
With the development of more advanced techniques for understanding minute (very small) changes in our body chemistry, scientists are beginning to piece together how our cells experience anxiety. Zuzanna Misiewicz and colleagues recently published a study on the molecular underpinnings of anxiety-related behavior. The authors used a multi-omics approach, measuring differences both in gene expression (genomics) and protein prevalence (proteomics), combined with a cross-species approach (measuring these factors in anxious/non-anxious mice and in panic disorder patients before and after they experienced a triggering event). The authors found that anxious behaviors are associated with a disruption of our cellular powerhouses known as the mitochondria. Mitochondria are tiny cell organs that create chemical energy for our cells.
Our mitochondria produce chemical energy in the form adenosine triphosphate (ATP), the molecule that is responsible for driving many cellular activities. What is exciting about this new research is its breadth: the authors measured multiple aspects of molecular activity (gene expression and protein levels) in an area of the brain that is implicated in the anxiety response. They also measured mitochondrial disruption in both mice and humans, instead of just one or the other and generalizing the results to apply to multiple species.
Where do these findings leave us?
To me, these robust results carry two implications. One is that the impact of anxiety on such a fundamental cellular process, one crucial to life, is both fascinating and concerning. Anxiety appears to negatively impact the very basic workings of our cells.
Our mitochondria have many important jobs in our body. One example is muscle contraction, which is required for movement. Muscle contraction requires large amounts of ATP (the energy-rich molecule produced by the mitochondria), which well-functioning mitochondria produce continuously. If mitochondria are inhibited with chronic anxiety, might that play out in terms of impaired muscle function?
ATP is also used for many other physiological (bodily) functions, including nerve signalling and heart beating. It is likely that an impairment in the ability of mitochondria to produce ATP, an essential energy molecule, could produce widespread negative impacts on our health.
The other implication of this new research is that a more minute understanding of what is happening in our body can help us develop more effective pharmacological therapies, perhaps those that carry fewer unpleasant side effects, are quicker to take effect and that reduce anxiety symptoms in a wider variety of patients.