Sleep, Depression, and Arousal
“When you are alert and paying attention to something important, your cortex is aroused. When you are drowsy and not focusing on anything, the cortex is in the unaroused state. During sleep, the cortex is in the unaroused state, except during dream sleep when it is highly aroused. In dream sleep, in fact, the cortex is in a state of arousal that is very similar to the alert waking state, except that it has no access to external stimuli and only processes internal events.”
Joseph LeDoux, The Emotional Brain
Disturbed sleep patterns are a distinct characteristic of depressive states. The most commonly reported disturbance is early morning awakening, where the person has little difficulty falling asleep but wakes in the early hours and is unable to return to sleep. Ironically, many people report that it is precisely when they have to get up that they finally feel ready to sleep again — an experience that is understandably frustrating.
Common characteristics of sleep disturbance include:
- Impaired sleep continuity and duration
- Decreased deep sleep
- Decreased latency to the onset of REM sleep
- An increased proportion of REM sleep in the early part of the night
Less common than early morning awakening are other disturbances in which the person is unable to remain asleep and fails to reach any satisfying depth of sleep. Another pattern involves prolonged difficulty in falling asleep, followed by relatively stable sleep once achieved. A further pattern is excessive sleep accompanied by persistent daytime exhaustion.
Sleep deprivation experiments demonstrate that prolonged deprivation results in hallucinations and delusions. Longer-term studies in rats show a syndrome characterised by physical debilitation, skin disorders, increased food intake, weight loss, lowered body temperature, and eventual death.
Curiously, observations of severely depressed patients suggest that short-term sleep deprivation may temporarily improve depressive symptoms. This can be compared with the effects of the serotonin antagonist reserpine (derived from Indian snakeroot), which produces a severe depressive state with long-term use.
Reserpine also increases REM sleep and dream frequency.
Typically, subjects who demonstrate severe psychological changes during sleep deprivation experiments fully recover following a prolonged period of natural sleep.
REM and Non-REM Sleep
If we divide sleep into two major categories — REM sleep and non-REM sleep — we can broadly describe the following features:
REM (Rapid Eye Movement) Sleep
1. REM sleep typically begins about 90 minutes after sleep onset. In depression, REM onset commonly occurs earlier. REM recurs throughout the night on a 90–100 minute cycle, with the first episode lasting less than 10 minutes and later episodes lasting 15–40 minutes.
2. Polygraph recordings during REM sleep resemble those of the waking state. REM sleep is sometimes referred to as paradoxical sleep.
3. Vital signs such as pulse rate, respiration, and blood pressure are relatively high, with marked minute-to-minute variability.
4. Brain oxygen demand increases beyond supply, suggesting an increased tolerance to carbon dioxide.
5. Thermoregulation shifts from external to internal control mechanisms.
6. The amino acid L-tryptophan, a precursor to serotonin, facilitates sleep onset and increases time spent in REM sleep.
7. Depressed individuals demonstrate earlier REM onset and increased REM concentration in the latter part of the night.
8. Awakening from REM sleep is usually rapid and accompanied by vivid dream recall.
9. The proportion of REM sleep decreases with age.
Non-REM Sleep
1. Pulse rate slows by approximately 5–10 bpm, with stable and regular cardiovascular activity.
2. Episodic involuntary movements may occur, including sudden jerks or falling sensations.
3. Abrupt awakening from deep non-REM sleep often results in confusion, disorganised thinking, and delayed return to baseline cognition.
4. Such disorientation has been linked to parasomnias such as sleepwalking, night terrors, and enuresis.
5. Cerebral blood flow is reduced, as it is in most bodily tissues.
6. In healthy adults, non-REM sleep accounts for approximately 75% of total sleep time.
Neurological Aspects of Sleep
- Sleep depends on complex interactions between the cerebral cortex and the central reticular formation; damage to the latter results in immediate loss of consciousness.
- Stimulation of the locus coeruleus — implicated in attention and hyperarousal — profoundly disrupts sleep.
- Patients with Alzheimer’s disease, involving loss of acetylcholine (particularly in hippocampal regions), show marked reductions in REM sleep.
- “Process S” refers to a hypothetical substance proposed to accumulate during waking hours and induce sleep pressure.
NLP Considerations
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Psychiatric literature consistently shows that the restoration of normal sleep patterns accounts for much of the therapeutic benefit of older sedating antidepressants. Given the extreme behaviours observed in sleep deprivation studies, lack of sleep must be considered a primary contributor to many of the symptoms reported by depressed clients.
This is a critical consideration for NLP practitioners designing hypnotic interventions for depression. In particular, attention should be paid to the client’s internal auditory tonality and submodalities. Teaching the client to use a hypnotic voice internally may be especially valuable.
It is also important to discover what the client does when unable to sleep. Do they lie awake ruminating? Become sexually aroused? Perform chores? Watch television? The behaviour itself becomes a maintaining strategy.
For clients who wake early and experience frustration, elicit the strategy underlying the awakening. Often the client wakes with guilt and immediately begins ruminating. This strategy can be disrupted and replaced with alternative activities or mental sequences.
Explore what strategies the client uses to achieve sleep. Many depressed clients are already medicated, but others rely on alcohol, illicit substances, or inappropriate over-the-counter remedies. One client nearly died from liver failure after consuming several grams of paracetamol nightly in an attempt to sedate emotional pain – despite paracetamol having no sedative or anxiolytic effect.
Other Considerations
Substance use is critical, as much of the work may otherwise become state-dependent. It may be appropriate to ask clients to abstain for several days before therapeutic work.
Caffeine consumption is frequently overlooked. Many depressed clients consume excessive amounts of tea, coffee, or caffeine tablets. Severe overuse can lead to dangerous cardiac effects. Encourage gradual reduction and improved hydration, especially later in the day.
Environmental factors are equally important. Assess the bed, mattress, bedding, room temperature, lighting, and bedroom behaviour. Is the bed used for work, television, or worrying? Is the bedroom contextually anchored to sleep and intimacy, or to stress and vigilance?
Research suggests that restricting the bedroom environment to sleep and sex alone can dramatically improve insomnia. From an NLP perspective, this approach aligns perfectly with principles of contextual anchoring.
Finally, consider medical conditions such as sleep apnoea, cardiac or pulmonary disorders, and medication side effects. When depression is the presenting complaint, collaboration with medical professionals may be essential to address underlying physiological contributors.