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Energy & sleep

Sleep, stress and anxiety

Alpha-Stim has been studied for anxiety mostly in the United States. The largest American sham-controlled trial, in 115 adults with anxiety and low mood, reported anxiety scores falling by about half with the active device against about a quarter with sham. A 2023 review of eight sham-controlled trials, six of them American, found less anxiety and better sleep, but the trials were small.

Evidence so far
Early
Reading timeAbout 12 minutes

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Why this is being studied

Stress, anxiety and poor sleep feed each other. A nervous system stuck on high alert struggles to switch off at night, and short or broken sleep keeps stress hormones high the next day. Alpha-Stim is a small device that sends a gentle current through ear clips while you sit quietly, and it has been used in the United States for anxiety and sleep for decades. The studies on this page come from American clinics and universities, including UCLA, and a review that pooled them. Results lean in a helpful direction, but the trials are small and independent groups have not always reproduced them. It is not a replacement for care from your GP if anxiety is affecting your life.

Where the evidence stands

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The mechanism

What is going on, and why this might help

What is going on in the body

Under ongoing stress, the body's alarm system stays switched on. Stress hormones such as cortisol stay high, the heart and breathing run faster, and brain activity shifts towards fast beta waves linked to alertness and worry. Anxiety disorders involve over-activity in the brain's threat circuits, including the amygdala, and weaker calming control from the front of the brain. This state makes it hard to fall asleep, and lost sleep in turn makes anxiety and low mood worse.

Where Alpha-Stim comes in

Alpha-Stim sends a very small alternating current, usually below the level you can feel, through clips on the ear lobes. A small fraction is thought to reach deeper brain structures involved in arousal and mood. Brain recordings with similar devices show more alpha waves, the slower rhythm of calm wakefulness, and fewer fast beta waves. Proposed effects include changes in brain chemicals such as serotonin and endorphins and a shift towards the body's rest-and-recover nervous system, but these are not well proven in people. A daily hour of sitting quietly may also help on its own, which is why sham-controlled trials matter.

How solid is this

Most of the trials are American. The largest, by Barclay and Barclay in 2014, found a large benefit over sham, and a 2023 review of eight sham or controlled trials (six American) found less anxiety and better sleep with no serious side effects. A US Veterans Affairs review in 2018 rated the evidence for anxiety as low strength because the trials were small and at risk of bias. Larger independent trials, including one in England for depression, have not found such clear benefits. We describe this as early.

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The studies

Every study is laid out the same way: what the researchers wanted to find out, who took part, what they actually did, what they found, why it might work and where the limits are. No jargon, and a link to the original if you want to read it yourself.

Each study is laid out the same way: what the researchers asked, who took part, what they did, what they found, why it might work, and where the limits are. The clinician layer at the end of each one carries the numbers.

Paper 1

A clinical trial of cranial electrotherapy stimulation for anxiety and comorbid depression

Barclay and Barclay · Journal of Affective Disorders · 2014 · randomised double-blind sham-controlled trial, n=115 (USA)

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What they asked

Anxiety very often comes with low mood, and the combination is harder to treat than either alone. Timothy and Raymond Barclay, working in private practice in the United States, ran a randomised, double-blind, sham-controlled trial to ask a simple question: over five weeks of daily use, does an active Alpha-Stim reduce anxiety and depression more than an identical-looking device that delivers no current?

Who took part

One hundred and fifteen adults with a primary anxiety disorder and depressive symptoms, recruited from a private practice population. 108 completed the trial. The active and sham groups started with similar anxiety and depression scores.

What they did

Everyone took home a device and used it with ear clips for 60 minutes a day for five weeks. Active devices delivered 100 microamps, below the level most people can feel. Sham devices looked and worked the same but delivered no current, and neither participants nor the clinicians scoring them knew which was which. Anxiety and depression were rated by clinicians on the Hamilton scales at the start and the end.

What they found

Anxiety scores fell by about 55 per cent with the active device against about 27 per cent with sham. Depression scores fell by about 55 per cent against about 24 per cent. Both differences were statistically significant and the effect on anxiety was large. Around 83 per cent of the active group had at least halved their anxiety score. No side effects were reported. The sham group also improved a good deal, which is common in anxiety trials.

Why it might work

The gentle current is thought to nudge brain activity towards slower, calmer alpha rhythms. A daily hour of sitting quietly may also help, which is what the sham group controls for. The gap between active and sham is what makes this trial notable.

Limits

A single site, run by the two clinicians who wrote it up, with no trial registration reported. Outcomes were measured only at five weeks, so we do not know how long benefits lasted. The effects are larger than most later and more independent trials have found. The authors reported no funding and no conflicts of interest.

Paper 2

A pilot study of cranial electrotherapy stimulation for generalized anxiety disorder

Bystritsky, Kerwin and Feusner · Journal of Clinical Psychiatry · 2008 · open pilot study, n=12 (UCLA, USA)

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What they asked

Generalised anxiety disorder means persistent, hard-to-control worry most days, often with poor sleep, tension and tiredness. Researchers at the UCLA Anxiety Disorders Program in Los Angeles ran a small pilot to see whether six weeks of Alpha-Stim was worth testing properly in this group.

Who took part

Twelve adults aged 29 to 58 with a diagnosis of generalised anxiety disorder, enrolled through the UCLA programme between 2005 and 2006.

What they did

Participants used an Alpha-Stim Stress Control System at 0.5 Hz and 300 microamps over six weeks. Anxiety was rated by clinicians on the Hamilton Anxiety Rating Scale and an overall improvement scale. A response meant at least halving the anxiety score and being rated much or very much improved. There was no sham group.

What they found

Anxiety scores fell significantly over the six weeks. Half of all 12 participants, and two thirds of those who finished, met the response definition. One more person improved substantially without quite meeting it. Side effects were mild, mostly headache and nausea.

Why it might work

The authors suggest the current may calm over-active anxiety circuits in the brain, in a similar way to other forms of brain stimulation. This pilot was not designed to test how it works.

Limits

Only 12 people and no sham or comparison group, so improvement could reflect expectation, natural ups and downs or simply the attention of being in a study. The authors describe it as preliminary. It is included because it comes from a major American university anxiety programme and led to further interest in controlled trials.

Paper 3

Efficacy of electrical cranial stimulation for treatment of psychiatric symptoms in patients with anxiety: a systematic review and meta-analysis

Chung et al. · Frontiers in Psychiatry · 2023 · meta-analysis of 8 sham or controlled trials, n=337 (6 of the 8 trials American)

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What they asked

Single trials of Alpha-Stim and similar devices are mostly small. This review pooled every randomised trial the authors could find that tested cranial electrical stimulation in people with anxiety, to get a clearer picture of anxiety, low mood and sleep.

Who took part

Eight randomised trials with 337 participants in total. Six of the eight were carried out in the United States, including the Barclay trial above, and four used Alpha-Stim. Seven compared the device with a sham.

What they did

The authors, based in Taiwan, searched five research databases up to February 2023, pooled the results and rated how confident they could be in each finding.

What they found

Anxiety fell more with active stimulation than with control, a large and consistent effect across the trials, which they rated as high certainty. In the four Alpha-Stim trials the effect was similar. Low mood also improved, with low certainty. Sleep improved in the three trials that measured it, though these involved only 53 people. Dropout rates were no different from control and no serious side effects were reported.

Why it might work

The review did not test mechanisms. The authors point to effects on brain rhythms and on brain chemicals involved in mood and arousal.

Limits

Eight small trials in total, several of them from the 1970s and 1980s, with unclear methods for allocating people in most. Sleep results rest on very few people. Long-term effects were not assessed. The authors declared no commercial conflicts. A 2018 US Veterans Affairs review of a wider set of trials was more cautious, rating the evidence for anxiety as low strength.