Sleepio

A recent study published in the prestigious British Medical Journal reports that children who do not get enough sleep have an increased likelihood of becoming overweight and obese.

Many previous cross-sectional and prospective studies have reported that sleeping less is associated with elevations in Body Mass Index (BMI), in both children and adolescents. These reports, however, have several limitations; often not taking into account important confounding factors (like parental size, physical activity, early-life weight etc.) and failing to use objective, reliable measures of both sleep and fat distribution.

Addressing these limitations, researchers from New Zealand assessed 244 children over a four year period – from when they were 3 through to 7 yrs of age. Sleep was assessed with an accelerometer waist-band, for five days, at ages 3, 4, and 5 yrs. BMI and measures of fat distribution (biochemical impedance analysis to gauge fat mass and fat-free mass) were also collected and used as the main outcome variables, being assessed annually between 3 and 7 years of age. It was found that longer sleep duration at ages 3-5 was linked to a reduction in BMI – 0.48 for each hour of sleep – as well as a 61% reduction in the risk of being overweight at age 7. Crucially, this association between sleep duration and BMI reflected changes in fat mass (as compared to fat-free mass, like muscle tissue) and was found after controlling for several factors that are known to influence obesity, such as physical activity, diet and parental variables.

This study provides strong evidence that reduced sleep duration plays a causal role in contributing to future obesity. Although the mechanism(s) behind how sleep loss may have an ‘obesogenic effect’, the authors suggest several possibilities: including alterations to hormones that regulate appetite, which may impact snacking behaviour; and reduced energy expenditure due to sleep-loss induced fatigue. Professor Colin Espie, Clinical & Scientific Director of Sleepio comments ‘this could be an influential piece of research. We already know just how important obesity is in explaining poor health. Now we see that good sleep predicts a healthy weight whereas insufficient sleep risks being overweight. Perhaps if young people see that protecting your sleep is an investment in your body shape and your weight, then they will be more likely to value a good night’s sleep’.

A new study, published online in the Journal of Clinical Sleep Medicine, reports findings from a trial of email-delivered cognitive behavioural therapy (CBT) for poor sleep in college students. The authors focussed on college students since they are known to have erratic sleep schedules and poor sleep quality, which could increase the likelihood of developing chronic insomnia and possibly future depression.

First year-college students from two halls of residence were assigned to either an eight-week programme called ‘Refresh’, or a programme called ‘Breathe’. The ‘Refresh’ programme involved the delivery of email PDF files to participants each week for eight weeks, covering the following main CBT components: education on sleep regulation; time in bed-restriction; relaxation training; mindfulness training; stimulus control strategies; and cognitive techniques. Each week, participants practiced the strategies described in the files. The participants in the ‘Breathe’ group received an intervention that was in equal in length but that, instead of covering sleep, targeted low mood and general stress. Baseline and post-treatment assessments of sleep quality and depression were conducted.

When looking at those reporting poor sleep quality at baseline, it was found that those in the ‘Refresh’ group (n=19) experienced a significantly greater improvement in sleep quality compared with the ‘Breathe’ group (n=15). Intriguingly, it was also found that the sleep-focussed ‘Refresh’ programme produced greater reductions in depressive symptoms compared with the ‘Breathe’ programme (where there was specific emphasis on mood and stress!). It is worth pointing out, however, that those in the ‘Refresh’ group had more severe depression scores at baseline relative to the ‘Breathe’ group, perhaps indicating that regression to the mean (when scores on first measurement are extreme, they tend to be closer to the average on second measurement) could partially explain this finding.

Such work complements other published literature demonstrating that self-help CBT for insomnia can effectively ameliorate core insomnia symptoms. If the depression result can be replicated, showing positive improvement in depressive symptoms through a sleep-focussed intervention, then this study also supports preliminary research demonstrating that improving sleep in depressed patients with insomnia disorder can also help improve the anti-depressant response.

A new study has systematically investigated the frequency and nature of depressive symptoms that remain in individuals with Major Depressive Disorder, despite responding favourably to the anti-depressant, Citalopram. It has been well documented that residual depressive symptoms, even for those who go into remission, increase the likelihood of future relapse. Less is known, however, about the nature of residual symptoms in individuals who respond to anti-depressant therapy (i.e. a 50% reduction in depression severity) but don’t fully remit. Such information could be used to guide interventions targeting specific residual depressive symptoms, at an early stage, to help enhance rates of remission.

Dr. Shawn McClintock, lead author of the study, and colleagues assessed 428 responders to Citalopram treatment (i.e. those showing a 50% decrease in depression symptoms as measured by the Quick Inventory of Depressive Symptomatology questionnaire). Repeat assessments with this questionnaire at 12 weeks were conducted to determine anti-depressant response (‘responders’) and residual symptoms. It was found that the two most common residual symptom domains, rated as moderately severe in nature, were insomnia (75.5% of the sample) and appetite/weight change (20.1%). It was also found that, out of those symptoms rated as mild by responders at follow-up, insomnia (94.6%), sad mood (70.8%), decreased concentration/decision making (69.6%), and psychomotor disturbance (69.9%) were the most common residual symptom domains.

When looking at subtypes of insomnia, it was found that middle-of-the-night insomnia (problems waking up during the night) was the most common complaint of sleep disturbance, and the most common residual depressive symptom in general. The team also assessed depressive symptoms that emerged during Citalopram treatment, and which remained at follow-up. Middle-of-the-night insomnia was the most common symptom which emerged during treatment (in 51.4% of individuals that did not report it at baseline), with decreased general interest being a close second (40%).

This work, published in the May edition of the Journal of Clinical Psychopharmacology, indicates that insomnia is the most frequent, persistent residual depressive symptom, as well as the most common treatment-emergent symptom in those who respond to anti-depressant medication. Professor Colin Espie, Clinical & Scientific Director of Sleepio comments “This is important work, because it emphasises that insomnia is a distressing, persistent and perhaps crucial problem when it comes to treating depression. Insomnia needs to be taken much more seriously than has been done in the past. There is also evidence from other research that people with insomnia are at much greater risk of relapsing back into depression, and that treating insomnia alongside depression may be the most therapeutic approach”’