Why do we dream?

Have you ever stopped to wonder why we dream at night? From sweet dreams to recurring nightmares, our mind is rarely silent – regardless of whether we can really remember their content in the morning.

Sometimes, we find our dreams are linked to things going on in our lives right now, worries about future events or strong memories from the past. This therefore seems to suggest that dreams are in some way linked to our memory, but exactly how, no one seemed sure.

Recent research has investigated the role of dreams and REM sleep (the phase of deep sleep) in the consolidation of long term memory. Consolidation just means the process whereby our memories move from short term to long term storage. In our long term memory, memories are stored for recall. Rehearsal (thinking about) these long term memories briefly involves short term processing, and this rehearsal strengthens the storage of these memories. Dreams may play a part in this consolidation and rehearsal process.

To find out more about REM sleep and our sleep cycle then why not read my previous post here.


Photo by clownbusiness/Shutterstock, with additional illustration by Lisa Larson-Walker

As I mentioned early, our dreams can have similarities to events which have taken place in our lives. Some research has focused on investigating the content of our dreams and found that the events which tend to be included in our dreams are ones which are rated as more emotional, although not more stressful, than those not incorporated (Malinoski & Horton, 2014). This suggests that REM sleep might help to process emotional memories. Further evidence to support this hypothesis is that levels of REM sleep are lower in people with depression (Cartwright, 1983) and PTSD (Ross et al, 1989).

However, although these dreams can contain elements of real life, they are often distorted: it is rare for the complete memory to be ‘played out’ in our dream. It is been suggested that this is because during sleep we cannot access full episodic memories (memories of events) but instead just traces of them.  This has been hypothesised to be due to reduced hippocampus (the part of our brain involved in memory processing) activity during REM sleep (Buzsàki, 1996). The fact that our dreams can contain strange events or impossibilities is thought to be due to a lack of activity in the prefrontal cortex – the area involved in attention and logic (Stickgold et al, 2001).

In addition to consolidating episodic memories another proposed function of our dreams is to enhance learning of procedural tasks (Smith et al, 1996). Studies in rats have found increased levels of REM sleep after procedural learning, and that less REM sleep resulted in poorer memory (Smith et al, 1985).

Whilst REM sleep and our dreams may be useful for certain types of memory consolidation, it doesn’t mean that this is the only way consolidation takes place, or that it is needed to consolidate every type of memory (Stickgold et al, 2001). The authors of this review hypothesize that dreaming enables the brain “to identify and evaluate novel cortical associations in the light of emotions… during REM”. To put it simply, when we dream our brain is working on processing new memories, learning procedures, and our emotions to events.



Seasonal Affective Disorder

It’s that time of year – the clocks have gone back, it’s cold, and already getting dark on our commute home. Whilst many people moan about this time of year, for some it can trigger symptoms of low mood and depression.

Seasonal Affective Disorder is defined as “a type of depression that comes and goes in a seasonal pattern.” (NHS Choices). It’s typically worse from December to February, getting better in spring and summer. For SAD to be diagnosed, there has to be clear evidence of worsening symptoms during winter, which can’t be explained by other circumstances (DSM-IV). In addition, there needs to be evidence for part or full remission during the summer months. Symptoms of SAD are similar to those of depression: low motivation and self-esteem, sleep problems, changes in appetite, withdrawing from social interactions and persistent negative thoughts.


Estimates of the prevalence of SAD range from 0 – 9.4% of the population, depending on who is being studied (Magnusson, 2000). One study compared rates of SAD at 4 different latitudes in the USA and found that is was most common in the northern latitudes (Rosen et al, 1990), which would be expected as SAD can be triggered by lower levels of natural light. This study also found higher rates of SAD in females than males (this finding is in line with overall levels of depression between men and women). It is thought to be caused by the lack of sunlight in winter months disrupting our circadian rhythm, which can be described as our internal body clock. This can affect the serotonin system in the brain, which is responsible in part for mood regulation.

There are various different treatment options for SAD, including light therapy, cognitive behavioural therapy, or antidepressants (Lurie et al, 2006). I’ve spoken about CBT before on this blog (see here for more information), so today I’ll just focus on light therapy and antidepressants as treatments for SAD.


Light therapy involves sitting by a specialised lamp, which emits a specified wavelength and brightness of light (at least 2500 lux). It is thought to work by encouraging the brain to produce serotonin – a neurotransmitter which is linked to feeling happy. Sitting by a lamp for 30 minutes to an hour each morning is the recommended ‘dose’ of light (NHS.uk). One meta-analysis has shown that light therapy is as effective as drug therapy in treating SAD (Golden et al, 2005).

Some antidepressants also work by increasing our serotonin levels. Known as SSRIs (selective serotonin reuptake inhibitors), they work by stopping as much serotonin from being reabsorbed at synapses in the brain and therefore leading to an increase in our mood. For antidepressants to be optimally effective in SAD, the NHS recommend starting to take them before winter and continue until spring.


Prevention is better than cure – Youth Mental Health in the UK

In Theresa May’s recent speech to parliament she stated that she wanted to end the stigma of mental illness and improve the state of mental healthcare in the UK. As a researcher into mental health services for children and adolescents, I hear often about the struggle parents have to get an appointment for their child to be seen by a psychologist, or the problems they face when care ends at 16-18, without the smooth transition to adult services enabling continuity of care.
Whilst it is vital that more money is spent on the NHS as a whole (recent talks of ‘crisis’ in A&E departments shows the obvious need for more resources), money which is promised to mental health services cannot be diverted to other areas which are struggling. These areas are definitely important, but they should not be funded to the detriment of youth mental health services.
Research by Young Minds (2014) found that 77% of NHS Trusts who responded had cut or frozen their Child and Adolescent Mental Health Service (CAMHS) funding between 2013 and 2015. Significantly, demand for these services increased over this time. This increase reflects a general trend over the last 20 or so years, for example the number of 15-16 year olds with depression nearly doubled between the 1980s and 2000s, and the number of young people being admitted to hospital for self harm has gone up by a massive 68% in the last 10 years (http://www.youngminds.org.uk/training_services/policy/mental_health_statistics).
Current services do not meet the need for care, with up to one in every four or five teenagers thought to have a mental illness. In a typical school, this would be around 3 in each classroom in the UK. With 75% of mental illness having an onset before the age of 24 (Kessler et al, 2005), it is vital that young people can access the services they need during this critical time in their development.
As mentioned above, care at CAMHS often ends when a young person is between the ages of 16 and 18. There are separate services for children and adults (CAMHS, versus AMHS) and this can represent a significant disruption of care. Young people have to move to a new adult service, in a new location and form a relationship with new healthcare professionals.  Previous research has found that only 4% of patients experienced an optimal transition (Singh et al 2010). Problems identified included a shortfall in time spent planning for transition, inadequate information transfer, and poor continuity of care. There may not even be an appropriate adult service in the local area which the young person can move to, for example in the case of autism or attention deficit disorder.
I am a researcher on the Milestone Project, an EU funded study currently investigating transition in nine different countries in Europe. My role involves interviewing young people and parents about their experiences of mental health services in the UK, and following them up over a period of time to see what happens to them when they leave CAMHS. The results of this study won’t be ready for some time, however it is clear to me that more needs to be invested into improving access for young people to mental health services.

Behavioural Activation

This week’s post is about a technique used as part of cognitive behavioural therapy for people with depression. As you probably know already, symptoms of depression include low mood, low self-esteem, feelings of anxiety and helplessness, and having low motivation and interest in activities which they previously enjoyed.

Behavioural activation focuses on the ‘B’ of the CBT model, in this case on the last symptom in particular – the withdrawal from usual activities and friends. For example, they may start to avoid social engagement and ignore invites from friends or make excuses as to why they can’t meet up, whereas before they would have been happy to go. Although in the short term this avoidance causes a temporary relief, such as a lowering of anxiety, it simply reinforces feelings of low mood or low self-esteem. This maintenance of the condition is illustrated by this diagram below:

Screen Shot 2016-07-28 at 19.49.10

Therefore, in order to break this cycle, behavioural activation aims to change the unhelpful behaviours which continue the cycle of low mood. It does this by gradually building up activities that the person can do, which is turn will improve their mood, and lead eventually to them getting back to activities they used to enjoy. This progression is important, as the change in mood is needed before larger behavioural changes can occur.

Key features of Behavioural Activation are as follows (taken from Jacobson et al, 2001):

  • Firstly, the model is presented to patients by their clinician, who explain a bit about it and why it works. This is called a treatment ‘rationale’ and it is important for the patient to feel confident that this will work. A good relationship and trust with the therapist is also important.
  • Developing treatment goals through collaboration between the patient and the therapist – these goals are new behaviours rather than moods or emotions.
  • Analysis of causes and maintenance factors of the depression
  • Graded task assignment – e.g. starting with something small such as walking to the corner shop. This is scheduled in between sessions, and a hierarchy is discussed with the therapist.
  • Establishing a routine, in the hope this results in improved mood.

Ultimately, the aim of Behavioural Activation is to help the patient re-engage and find joy in activities which they have been avoiding. This will raise mood, and therefore help someone recover from depression.

Why more money needs to be spent on improving access to mental health treatments

This week in the UK is Mental Health Awareness Week, so today’s post will be a bit different – what are the main issues about treating mental illness in our society, and how can access to therapy be improved?

Firstly: not enough money is being spent to improve access to mental health services in the UK. Fact. This means not everyone who needs access to treatment gets it, which, as well as having a massive impact on society, has an extreme effect on our economy too.

The statistics are striking:  only 25% of people with mental illness are in treatment, compared to almost 100% of people with physical health issues (Layard et al, 2012). And mental illness isn’t rare – the World Health Organisation found that mental illness makes up about 40% of all illness in developed countries. In the UK, 15% of the population of the UK suffer from anxiety or depression, but only 5% of those are in treatment (Depression Report, 2005).

Morbidity among people under age 65
Morbidity among people under age 65

And why are these individuals not receiving treatment? A report carried out by several mental health charities found that 1 in 4 primary care organisations do not offer Cognitive Behavioural Therapy – the treatment recommended by NICE for all anxiety disorders and depression. It is therefore clear that more needs to be done to improve access to therapy in the UK.

However, once a patient has been offered therapy, the problems of lack of funding do not go away. Waiting lists can be as long as several months, by which the problems could have got worse. This is another area where there is a massive disparity between mental and physical health services.

Therefore, it seems obvious that more money should be invested in mental health services within the NHS. This comes at a time where the NHS budget is stretched to the limit, and the government are looking at cutting funds to public services. And here’s the clever bit: improving access in mental health services would pay for itself. 

Let’s look at the economic cost of mental illness in the UK. In 2005, it was estimated that anxiety and depression cost the UK about £17 billion per year. About half of disability benefits are paid to people with mental illness. One study found that less than 25% of people with long term mental illness have a job, compared to about 75% of the rest of the working-age population. Therefore, this results in a massive loss of revenue from taxes, as well as increased expenditure on benefits and sick pay.

Even when people are at work, mental illness can reduce productivity and so cost the company money. A NICE study found that improving management of mental health in the workplace could save 30% of reduced productivity and sick pay costs. If a company has 1,000 employees, this equates to a saving of £250,000 per year.

Mental health also has a significant impact on our physical health, which causes more pressure on the health service. Hutter et al (2010) found that individuals with mental health problems use 60% more physical health services than people who are equally ill but do not have mental health problems. This costs the NHS about £10 billion per year. These figures are striking, and show more money, not less, needs to be invested in mental health services.

The massive economic costs of mental illness are clear, but what about savings from improving access to treatment? Layard et al (2007) found that its costs £630 to treat a patient, but this leads to £4,700 in benefits to society in the form of more people off disability benefits and back as work, so paying more taxes, and less spent on physical health services and sick days.

Fortunately, things are being done to make mental health treatment more accessible. For example, Improving Access to Psychological Therapies (IAPT), which aims to train more therapists for specialised local services. So far, this initiative has treated about 756,000 patients a year, with 45% recovering completely, 60% showing a reduction in symptoms, and 5% being well enough to come off sick pay and benefits and return to work.

This just shows the positive impact of expanding mental health services in the UK, and making treatment available for those who need it. At a time when the country is undergoing a change in government, these issues need to be remembered and prioritised. Even with cuts, and less money available, these statistics show that more money, not less, needs to be spent on mental health services in the UK.