Trauma refers to life-threatening events that overwhelm the nervous system. The overwhelmed nervous system becomes dysregulated by ongoing continuous autonomic nervous system activity. This hyperactivation of the sympathetic or parasympathetic arms of the ANS is marked by intense sensory memories: for example, the sound of squealing tires before a crash, the image of rage on a parents face before being hit, or other smells and physical bodily sensations. A dysregulated ANS can trigger at least a dozen different sleep disorders (see chapter 1 of Putting Trauma to Sleep).
Insomnia is more than a nighttime problem with getting asleep and staying asleep. Insomnia is a 24-hour-a-day problem with a dysregulated autonomic and emotional nervous system.
· For those with PTSD, insomnia frequently stems from a deeper fear of losing control and feeling helpless and alone, which going to sleep represents.
· The body’s alarm system, the Locus Coeruleus, releases norepinephrine (LC-NE) to fight the instinct to rest. Persistent (tonic) activation of the LC-NE results in increased cognitive arousal (a racing mind) and unpleasant activation of body muscles (tension and achiness).
· Tonic LC-NE activity also activates other nearby arousal nuclei in the brainstem (see DRN, and PAG), and the midbrain (LH and PVN). See diagram above.
· These collectively support persistent stress activation which interferes with the PPT and LDT (REM promoting) nuclei, to effectively prevent stable periods of REM sleep.
· This tonic LC-NE overactivity also keeps the reticular arousal system (RAS) engaged, which both prevents deep, slow wave sleep (SWS) and creates REM instability.
· Research shows that people with PTSD experience increased brain activity that disrupts their normal restorative sleep cycles. Instead of the restful, sleep-promoting brain patterns (A1 CAPs), PTSD patients have more arousal signals (A2 and A3 CAPs), leading to fragmented, shallow, and short sleep.
· The resulting Restless REM creates chronically fragmented short sleep, which prevents the normal process of desensitization (nightly emotional adaptation within the amygdala) as well as impaired long-term memory consolidation in the cortex.
· Therapists can screen for insomnia with tools like the Sleep Condition Indicator (SCI), the Insomnia Severity Index (ISI), or the Fear of Sleep Inventory (FoSI). See Resources tab above.
· Addressing these fears is critical for improving sleep and overall well-being. See chapters 1, 9 and 12 in Putting Trauma to Sleep for more information on assessing and treating chronic insomnia.