SLEEP DISORDERS

What are the sleep disorders associated with psychiatric conditions?

Sleep problems are common in individuals with psychiatric conditions, including depression, anxiety (post-traumatic stress disorder, generalized anxiety disorder, and panic disorder), bipolar disorder, schizophrenia, dementia, and substance abuse. Insomnia is the most common reported sleep problem related to psychiatric disorders. In mania, and possibly in depression, insomnia can worsen the condition, and early intervention to improve sleep may help to abort a relapse. Also, insomnia can signal an imminent relapse. In addition to increased insomnia, there can also be an increased incidence of parasomnia, circadian rhythm disorders, and hypersomnia. For these reasons, I always inquire about sleep as a routine part of patient assessment.

Insomnia is the most common symptom in depressed individuals, and is often the reason why they seek help. 75% of depressed individuals have insomnia (difficulty falling asleep, fragmented sleep, early-morning awakening, decreased amount of sleep, etc…). Insomnia tends to improve as mood lifts, and such relief of sleep disturbance may encourage individuals to adhere to antidepressant treatment. 5-10% of depressed individuals have hypersomnia, which is commonly associated with atypical depression.

Sleep problems are highly common in Post-traumatic stress disorder (PTSD). Around 70-90% of individuals with PTSD have difficulty falling asleep or staying asleep, and nightmares are reported by 20-70%. Parasomnias such as sleep walking and night terrors are more common than in the general population. More recently, a high incidence of sleep-disordered breathing and sleep movement disorders has also been reported.

In Generalized anxiety disorder (GAD), sleep onset insomnia is experienced by 20-30% of individuals, and sometimes sleep is the main focus of anxiety. They may also have increased night-time awakenings and report poor sleep quality. Individuals may spend hours ruminating before sleep onset, and the negative consequences of having too little of it.

There are no specific associations between panic disorder and sleep disorder except in those individuals who experience night-time panic attacks. Up to 50% of panic disorder individuals have at least one of these nocturnal panic attacks, and 30% experience them regularly. In this group fear of falling asleep becomes a problem, and they describe sleep onset insomnia.

Individuals with schizophrenia can suffer from insomnia, which is mostly described at times of acute symptoms. They may also experience prolonged sleep or excessive napping in the day, and although this is often thought to be due to the adverse effects of sedating antipsychotic medication, there may be other factors that have only been recently been identified, especially circadian dysregulation.

Increasing age in healthy people is associated with increasing amounts of waking during the night, and this characteristic appears to be worse in dementia, so there is often insomnia. More extreme fragmentation of the 24-hr sleep-wake pattern with more sleeping in the daytime and less at night is also common and, of course, compounds the issue as daytime naps reduce the drive to sleep at night, and poor sleep at night makes daytime napping more likely.

During acute alcohol and opiate withdrawal, there are usually severe problems with insomnia. This is probably due to a massive rebound activation of brain arousal systems, especially the noradrenaline projections from the locus coeruleus to the cortex. For reasons that are unclear, but may reflect interactions with other neurotransmitter systems, sleep problems are more prolonged and probably more distressing in people withdrawing from methadone, and there is some evidence that this insomnia is still present at 6 months of abstinence.

Sleep problems are not only distressing but also may predict relapse in abstinent alcohol-dependent individuals. Individuals who had insomnia while they were drinking are twice as likely to relapse as those with a normal sleep pattern. In addition to these symptoms of insomnia, abstinent alcoholics often have a chaotic lifestyle, which has become established during drinking and takes a long time to settle down to a regular pattern.

Chronic use of amphetamine and other stimulants is associated with shortened sleep duration and REM suppression, which is due to the direct effects of the drugs releasing dopamine and noradrenaline in the brain. Adaptive homeostatic changes occur in the brain so that during the first 2 weeks of withdrawal there is a rebound of both of these. This leads to the clinical symptoms of daytime sleepiness and fatigue and the nocturnal effects, especially of increased REM sleep, with associated reports of vivid and unpleasant dreaming.

What is the treatment of sleep disorders associated with psychiatric conditions?

The ability of antidepressant medications to improve sleep early in treatment is often important to patients, particularly if insomnia causes significant distress. Also, early improvement of sleep symptoms may encourage the individual to carry on with medication to the point where the mood-lifting effects become apparent (usually within 3-4 weeks).

Antidepressants that are 5HT2 blockers, such as Mirtazapine (Remeron), can improve subjective sleep quickly in depression. Tricyclic antidepressants (TCA) such as Amitriptyline (Elavil) and Doxepin (Silenor) also do this, because they are potent histamine H1 antagonists, but have more unwanted side effects such as carry-over sedation and dry mouth.

In large clinical trials, it has been shown that sleep problems in generalized anxiety disorder (GAD) improve along with other symptoms after effective antidepressant treatment. Cognitive behavioral therapy (CBT) focusing on sleep also appears to be efficacious in this group, similar to its actions in individuals with primary insomnia.

Medication therapy used for PTSD symptoms, such as SSRIs, Trazodone, and Mirtazapine, may improve sleep and nightmares. More recently, there have been encouraging reports of sleep improvements after treatment with Prazosin, a centrally acting alpha1-adrenoceptor antagonist, and also Buspirone (Buspar), Gabapentine (Neurontin), which need to be confirmed. Evidence suggests that benzodiazepines, Tricyclic antidepressants (TCAs), and monoamine oxidase inhibitors (MAOIs) are not useful for the treatment of PTSD-related sleep disorders.

Cognitive behavioral interventions that target insomnia and imagery rehearsal therapy for nightmares have also demonstrated good outcomes.

The treatment of sleep problems in alcohol and opiate withdrawal should focus on cognitive and behavioral strategies to improve sleep habits and reduce anxiety about the consequences of lack of sleep. Medication treatment is probably contraindicated, but in alcoholics with depression a more sleep-promoting antidepressant (e.g. mirtazapine, trazodone) would be a sensible choice. In early opiate withdrawal, antihistamines have been successfully used to improve sleep onset insomnia. It is worth noting that the use of alpha2-adrenoreceptor agonists such as clonidine to treat opiate withdrawal may also improve sleep by switching off arousal systems, so these medications can be given at night as well as in the day.