Quick version
No, anxiety cannot be measured solely through blood tests. Although blood tests can provide some insight into the body's stress response and inflammatory processes, there is currently no single test that can reliably measure or diagnose anxiety.
Anxiety activates the body's stress system, which can lead to altered levels of hormones such as cortisol, adrenaline and noradrenaline. Studies have also shown that inflammatory markers such as CRP and IL-6 can be elevated in long-term anxiety. The brain's neurotransmitters, such as serotonin and dopamine, play an important role in anxiety but are difficult to measure via blood tests.
The challenge is that these biomarkers are not specific to anxiety and can be affected by many other factors, such as stress, lack of sleep and physical activity.
No, anxiety cannot be measured solely through blood tests
Although blood tests can provide some insight into the body's stress response and inflammatory processes, there is currently no single blood test that can reliably measure anxiety.
When we experience anxiety, the body's stress system is activated, leading to an increased release of hormones such as cortisol, adrenaline and noradrenaline. These hormones prepare the body to handle stress by increasing heart rate, increasing blood pressure and improving energy mobilization. In short-term stress, cortisol levels are often elevated, but in long-term anxiety, the system can become dysregulated, which can lead to both elevated and lowered cortisol levels depending on the situation.
Adrenaline and noradrenaline, which are involved in the body's "fight-or-flight" response, have also been shown to be elevated in certain anxiety conditions, especially panic disorder. Research has shown that people with anxiety may have higher levels of these stress hormones in their blood, reflecting the increased physiological activation that occurs with anxiety.
Inflammation markers and anxiety
In addition to hormonal changes, researchers have found that anxiety can be linked to low-grade inflammation in the body. In the event of prolonged stress and anxiety, the immune system can be activated, leading to an increase in inflammatory substances in the blood. CRP (C-reactive protein) and cytokines such as IL-6 and TNF-α have been shown in several studies to be elevated in people with anxiety compared to healthy individuals.
There is also research that suggests that inflammation can affect the brain's signaling pathways and thus contribute to the experience of anxiety. In experiments where inflammation has been induced in healthy subjects, some have experienced increased feelings of anxiety, suggesting that there is a connection between immune activation and psychological well-being.
Signaling substances and other biomarkers
The brain's signaling substances, such as serotonin and dopamine, are also regulated in anxiety and can be related to anxiety disorders, but since serotonin primarily acts in the brain, it is difficult to measure directly via blood tests. Instead, researchers have investigated indirect markers, such as serotonin breakdown products and its uptake into blood platelets.
Furthermore, studies have shown that people with anxiety may have lower levels of BDNF (Brain-Derived Neurotrophic Factor), a protein that is important for the brain's nerve cell survival and plasticity. Low BDNF levels have also been observed in depression and may be part of the biological basis of psychological disorders.
Limitations of blood tests to measure anxiety
Although some blood markers can reflect biological changes in anxiety, there are major limitations in using blood tests to diagnose or measure anxiety levels. Many of these biomarkers are not specific for anxiety and can just as easily be elevated in other conditions, such as stress, depression or inflammation. For example, cortisol and adrenaline can be affected by physical activity, sleep deprivation or caffeine intake, making them unreliable as direct measures of anxiety.
Another challenge is that the biological changes that occur in anxiety primarily occur in the brain, and not all substances that affect brain function can be measured in the blood. In addition, the levels of many biomarkers vary greatly over the course of the day and are affected by several external factors, making it difficult to obtain a stable and reliable measurement.
Conclusion
Currently, there is no single blood test that can reliably measure anxiety. However, blood tests can provide some information about the body's stress response and inflammatory state, which may be relevant in the investigation of long-term stress and mental illness. Research is underway to identify a combination of biomarkers that can reflect anxiety levels more accurately. In the future, it may be possible to use blood tests as a diagnostic aid, for example to exclude other causes or monitor the effect of treatment. For the time being, however, anxiety is primarily a clinical diagnosis made through conversation and symptom assessment – not through single blood tests.
