Friday 18 March 2011

Sleep, melatonin and autism

"Look into the eyes, not around the eyes, into the eyes.. and.. you're under". Famous words from Kenny Craig the Stage Hypnotist from Little Britain. If you could add the words "you will sleep for 8 hours... 3,2,1.. you're back in the room" after that and it works, many people would be very, very, very happy.

Ask any person with children, irrespective of an autism diagnosis or not, what are the toughest things about raising a child and I bet many will list a lack of sleep in the early years as being fairly close to the top of their list. Gone are the heavenly 8-hour slumberthons that were taken for granted each night. Replaced instead by 1-2 hours, then 2-3 hours, etc working up to a full night by about a year (if you are lucky) and even then not in uniform stages.

For the first few months of your child's life, you wake up looking and feeling like the living dead; despising the sound of the morning chorus which you heard start at 4am, constantly thinking about how you are going to get through the day without crashing the car and yearning for those golden 8-hour nights to return. The world passes by in slow motion. It is not something that the mind and body ever really gets used to and demonstrates how powerful a thing sleep deprivation can be, and how it impacts on many parts of your life.

Think then to how a child who suffers similar sleeping problems might also feel as a result of disturbed, unrefreshing, qualitatively poor sleeping patterns; where the body clock just somehow does not seem to keep time with the environment around them and the time spent sleeping is limited.

Think about what impact this might have on the developing body and brain and how irritability, non-compliance, and inattention at home and school (so-called 'challenging behaviours') might come about as a result. Interesting thought isn't it?

Autism including Asperger syndrome, similar to conditions such as learning disability, impacts on sleep. That's what we think anyway - autism impacts on sleep, or does sleep impact on autism? Whichever way round, there is a wealth of research to suggest that sleeping problems are common for a large group of people on the autism spectrum above and beyond the early years.

The UK National Autistic Society has a very large on-line document about autism and sleep which kinda gives a flavour of how pervasive and widespread the issue is. Dr Jacqui Jackson gave a good insight into her experience of sleeping problems related to autism (and other co-morbidities) in her family back in 2006.

The published research in this area suggests that children with an autism spectrum condition are more likely to present with shorter overall sleep time, less REM sleep (see description here), more incidents of night-waking, and indications of disordered circadian rhythms (see description here) when compared to non-autism and developmentally delayed controls. I would imagine that all that could/would cause a lot of stress and anxiety both to the child and their parents if delivered over a sustained period of say, years.

The questions then: what causes such sleeping problems in relation to autism and what can be done about it?
Unfortunately there are no cut-and-dried answers; only fragments of information which potentially point to many different mechanisms and once again, variability in the mode of action across the spectrum.

Before delving into the world of circadian rhythms and melatonin, which seem to provide the best explanations of sleeping problems in autism, I want to go back to something mentioned in the BBC report on Jacqui Jackson's family: the issue of co-morbidity.

As mentioned many times on this blog, several types of co-morbidity can be, and are, present alongside autism, including learning disability and attentional problems (ADHD). Both these example co-morbidities are associated with sleeping problems.

In ADHD, sleep problems are reported to be present in between a quarter and a half of children diagnosed. Given that autism can often be co-morbid with ADHD, there is perhaps a case for suggesting that at least some sleeping problems may be more related to the ADHD-symptoms/label over the autism? The point I am trying to make is that autism alone cannot perhaps be held responsible for all sleep disturbances at least in some children.

Back to circadian rhythms and melatonin. Our circadian rhythm is our internal clock. Working with our external environment (light and dark), it regulates many different functions including most importantly our sleep-wake cycle.

I remember quite a few years back speaking to several parents who indicated that their child's sleep-wake patterns were cyclical. That is for a few days of the month, sleep would not be a problem, but the days either side, the child seemed to sleep at different times outside of those normally expected with a more variable sleep quality.

This is an interesting phenomena. One would hope that our circadian rhythm runs parallel to our 24-hour clock. The reality however is that we all make subtle changes to our clock as a result of our environment (light or dark) and other factors. Could it be that this modification is unresponsive somehow?

Well, we do know that measures of stress such as cortisol levels are different in autism, and whilst trying not to make sweeping generalisations, it appears that stress levels continue into the evening where perhaps they should be dropping. Could this explain some of the sleep problems?

There is also a suggestion that some of the so-called 'clock genes' might be under-performing in autism (although this does require a lot more study and needs to take on board a few issues previously blogged about).

We also have a potential role for melatonin. Melatonin is a naturally-occurring metabolite of tryptophan. In its commercial form it is the drug of choice for overcoming jet-lag being widely available in the USA, although not licensed for sale in the UK at present.

There is quite a bit of research on melatonin and autism. There is research that suggests a tendency towards abnormal melatonin synthesis in autism (bearing in mind it is a derivative of serotonin, 5-HT, which already has an interest to autism). There is research that suggests lower levels of melatonin is secreted in autism. There is also a suggestion (not so much research) that pineal function in autism may be altered. There are also quite a few studies indicating that supplementation with melatonin might be beneficial for some cases of sleep problems in autism; a view backed up by Research Autism (two ticks = strong evidence).

One could therefore assume that melatonin may play at least some role in the sleep problems reported in autism. Is it the main cause? I dunno.

We perhaps should not discount that sleep is often not just about biology; it is environment, it is psychology, it is routine, it is about lots of things combined. If sleeping problems are present to some considerable degree, we should perhaps also be more 'aware' of its possible impact on presented behaviour rather than immediately reaching for the anti-challenging behaviour handbook.

A final word for those familiar with Kenny Craig - "cupboardy". If you are not familiar, watch the video.

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