Norepinephrine (NE) is the neurotransmitter often associated with the “fight or flight” response to stress. Strongly linked to physical responses and reactions, it can increase heart rate and blood pressure as well as create a sense of panic and overwhelming fear/dread. This neurotransmitter is similar to adrenaline and is felt to set threshold levels to stimulation and arousal. Emotionally, anxiety and depression are related to norepinephrine levels in the brain, as this neurotransmitter seems to maintain the balance between agitation and depression.
Low levels of norepinephrine are associated with a loss of alertness, poor memory, and depression. Norepinephrine appears to be the neurotransmitter of “arousal” and for that reason, lower-than-normal levels of this neurotransmitter produce below-average levels of arousal and interest, a symptom found in several psychiatric conditions including depression and ADHD. It is for this reason that medications for depression and ADHD often target both dopamine and norepinephrine in an attempt to restore both to normal level.
Mild elevations in our norepinephrine levels produce heightened arousal, something known to be produced by stimulants. This arousal is considered pleasurable and several “street drugs” such as cocaine and amphetamines work by increasing the brains level of norepinephrine. This increased sense of arousal is pleasurable, linking these substances to their potential for addiction. Research tells us that some individuals using antidepressants develop a state of “hypomania” or emotional elation and physical arousal in this same manner. For that reason, individuals using modern antidepressants are often cautioned to notify their treating physician/psychiatrist if they become “too happy”.
Moderately high levels of norepinephrine create a sense of arousal that becomes uncomfortable. Remembering that this neurotransmitter is strongly involved in creating physical reactions, moderate increases create worry, anxiety, increased startle reflex, jumpiness, fears of crowds & tight places, impaired concentration, restless sleep, and physical changes. The physical symptoms may include rapid fatigue, muscle tension/cramps, irritability, and a sense of being on edge. Almost all anxiety disorders involve norepinephrine elevations.
Severe and sudden increases in norepinephrine are associated with panic attacks. Perhaps the best way to visualize a panic attack is to remember the association with the “flight or fight” response. The “flight or fight” response is a chemical reaction to a dramatic and threatening situation in which the brain produces excessive amounts of norepinephrine and adrenaline – giving us extra strength, increased energy/arousal, muscle tightness (for fighting or running), and a desperate sense that we must do something immediately. This animal response was activated in early man when a bear showed up at his cave or when faced with a tiger in the woods. In modern times, imagine your reaction if while calmly watching television, someone or something started trying to knock your front door in to attack you. In the “flight or fight” reaction, your brain and body chemistry prepare you to either run from the situation or fight to the death!
A panic attack is the activation of the “flight or fight” chemical reaction without a bear at the door. It’s as though the self-protection animal response is kicking-off accidentally, when no real life-threatening situation is present. Known now as panic attacks, they can surface at the grocery, at church, or when you least expect it. As norepinephrine is a fast-acting neurotransmitter, the panic attack may last less than ten minutes (feels like hours however!) but you’ll be rattled/shaken for several hours. Panic attacks are strong physical and chemical events and include the following symptoms:
· Palpitations, pounding heart or rapid heart rate
· Sweating and body temperature changes
· Trembling or shaking
· Shortness of breath of smothering sensations
· Choking sensations
· Chest pain and discomfort
· Nausea or stomach distress
· Dizziness, lightheadedness, or feeling faint
· Sense of unreality, as though you are outside yourself
· Fear of losing control or going crazy
· Fear of dying
· Numbness and tingling throughout the body
· Chills and hot flushes
If we think about the automobile example, a panic attack is the equivalent of your dashboard warning lights coming on – your stress level is too high. Panic attacks, or surges of norepinephrine, can also occur by accident as when created by the use of certain medications. The medications for certain medical conditions can cause a panic attack or increase our level of anxiety. Medications often used for asthma, for example, can create anxiety or panic attacks.
Treating low or elevated levels of norepinephrine in the brain involve different approaches. Low levels of norepinephrine are often treated using newer antidepressants. Many new antidepressants, known as Serotonin-Norepinephrine Reuptake Inhibitors (SNRI’s) with brand names like Effexor and Serzone, treat depression by increasing levels of both serotonin and norepinephrine neurotransmitters.
Treatment for high levels of norepinephrine, as found in anxiety and panic disorders, involves decreasing neurotransmitter levels directly or using medications which increase another neurotransmitter that inhibits or decreases the action of norepinephrine. One of those inhibiting neurotransmitters is GABA, also known as Gamma-Aminobutyric Acid.
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