Smartphones and Sleep Data: Data Mining

Smartphones contribute a treasure trove of data that is likely to expand our knowledge of a variety of human behaviors.

An example of this is a recent study published in Science Advances by a research team from the University of Michigan.

The University of Michigan team developed a smartphone app called ENTRAIN and then used the app to collect sleep data on subjects from around the world.

They came up with some very interesting findings including the following:

• The time of going to sleep appears more influenced by social environmental factors.
• The time of awakening appears influenced primarily by biological factors
• Exposure to sunlight versus indoor light also appears to influence sleep patterns
• Sleep pattern variability is strongly related to age

The age effect in sleep in their study being:

"That the older population is more homogeneous in their sleep habits because there is a narrower range of circadian phases at which they can readily sleep."

This is an important study that highlights what we can learn from smartphone data that can be applied to population problems such as lack of adequate sleep.

Read about this study at Medical Xpress here.

The free full text manuscript can be accessed by clicking on the DOI link in the manuscript below.

Figure reproduced in this post is from a Wikipedia Creative Commons figure cited below:

By Google, AOSP - User-created screenshot, Apache License 2.0, https://commons.wikimedia.org/w/index.php?curid=42781988 

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Walch, O., Cochran, A., & Forger, D. (2016). A global quantification of "normal" sleep schedules using smartphone data Science Advances, 2 (5) DOI: 10.1126/sciadv.1501705

Low-dose Doxepin for Insomnia Treatment

Doxepin is a tricyclic antidepressant drug with significant sedative effect recently studied for use as a hypnotic in the treatment of insomnia.  Doxepin has strong antagonistic effects on several neurotransmitter receptors including the histamine (one and two), serotonin (two), alpha one adrenergic and muscarinic acetylcholinergic receptors.

Juliane Weber and colleagues recently reviewed clinical trial research related to doxepin and insomnia treatment.  For depression, doxepin typically requires 150 mg to 300 mg to achieve an antidepressant.  Many individuals are unable to tolerate this type of dose due to the sedative side effects.  Much lower doses (3 mg to 6 mg) have been investigated for effects on sleep.

A summary of the key points from their review:

• Doxepin decreased time awake after onset of sleep by 40-46%
• Total sleep time increased from 40 to 50 minutes per night
• Proportion of sleep time in REM and slow wave sleep did not change
• Elderly patients had similar effects with the lower 3 mg dosage
• Effects were similar for patients with chronic or transient insomnia
• In sleep lab testing doxepin reduced time to sleep onset from 35 minutes down to 20 minutes

A more recent study from Krystal and colleagues at Duke University looked at 1 mg and 3 mg doses of doxepin in elderly patients with chronic primary insomnia.  They found the 3 mg dose was effective in reducing wake time after sleep onset, total sleep time and overall sleep efficiency (percent of time asleep).

The duration of doxepin's effect has been studied for up to 12 weeks and there does not seem to be tolerance to the hypnotic effect over this duration.  At these low doses, doxepin appeared well-tolerated.  Longer term studies are needed to determine efficacy for periods of longer than 12 weeks.  One potential concern would be weight gain as the histamine and muscarinic receptors appear to be related to increased appetite and weight gain.

The FDA has approved doxepin 3 mg and 6 mg for insomnia treatment.  Typically, the lowest generic doses for this drug are 10 mg.  Three mg and 6 mg doses are available under the brand name Silenor.

This research suggests low-dose doxepin may be an alternative to hypnotics such as Ambien (zolpidem) for primary insomnia.  This research supports further study of current drugs for novel mechanisms and new indications.


Disclosure:  The author has no financial conflict of interest and has not received funding for research of this compound.

Image of chemical structure for two isomers of doxepin courtesy of Creative Commons authored by Ju.

Weber J, Siddiqui MA, Wagstaff AJ, & McCormack PL (2010). Low-dose doxepin: in the treatment of insomnia. CNS drugs, 24 (8), 713-20 PMID: 20658801

Krystal AD, Durrence HH, Scharf M, Jochelson P, Rogowski R, Ludington E, & Roth T (2010). Efficacy and Safety of Doxepin 1 mg and 3 mg in a 12-week Sleep Laboratory and Outpatient Trial of Elderly Subjects with Chronic Primary Insomnia. Sleep, 33 (11), 1553-61 PMID: 21102997