GME Logo

User login

User menu

Issue 67, Nov 2017
Share This
Is cannabis a potential treatment for PTSD?

O'Neil ME, Nugent SM, Morasco BJ, Freeman M, Low A, Kondo K, Zakher B, Elven C, Motu'apuaka M, Paynter R, Kansagara D. Benefits and Harms of Plant-Based Cannabis for Posttraumatic Stress Disorder: A Systematic Review. Ann Intern Med. 2017 Sep 5;167(5):332-340. Review. PubMed PMID: 28806794.


Cannabis is legal for medicinal use in an increasing number of states of the US and many of these states list posttraumatic stress disorder (PTSD) as one of the indications for its use.

Of persons who ask for cannabis for medical reasons in states where such use is legal, more than one-thirds list PTSD as the main reason for requesting cannabis.

Many stories have been reported in the press about persons whose PTSD symptoms improved after use of cannabis.

There are also reports that some persons with more severe PTSD were using cannabis to cope with their symptoms.

But, is there good research evidence that cannabis really works for PTSD?

The Veteran’s Health Administration obviously has a strong interest in the treatment of PTSD. It has commissioned a large report on the topic of cannabis and PTSD and the paper discussed below is part of that larger project.

This paper aimed to review the published research data on the efficacy and adverse effects of plant-based cannabis for the treatment of posttraumatic stress disorder.


A thorough and systematic search of the literature was conducted and relevant articles and studies were identified. But only articles in English were included.

Study data were extracted and evaluated using a structured process.

Only studies of plant-based cannabis preparations or whole-plant extracts with a standard composition and dosage were included.

Studies of synthetic cannabinoids like dronabinol and nabilone were not included because these are not available in dispensaries and their potential use for PTSD has been reviewed previously.


Two systematic reviews and three observational studies about the use of cannabis to treat PTSD were found. It is important to note that no randomized clinical trials on such use of cannabis were found.

The observational studies did not find cannabis to reduce PTSD symptoms. Either there was no improvement or persons who used cannabis had worse outcomes.

The systematic reviews concluded that there was insufficient evidence to draw conclusions about the benefits or harms of using cannabis for the treatment of PTSD.

Some evidence was also found that cannabis use was associated with an increased risk for psychotic symptoms and mania. In active users, it was also associated with an increased risk of short-term cognitive dysfunction.


Currently, there is insufficient evidence to support the use of cannabis for the treatment of PTSD.

There are many studies going on this topic, including two randomized controlled clinical trials, and their results are expected in the next few years.

Clinical Commentary

While the research published so far has not shown that cannabis is effective for PTSD, we should note that it hasn’t ruled it out either.

In the observational studies reviewed in this paper, participants chose to use cannabis and were not randomized to take it or a control substance. So, it becomes a chicken-and-egg question—did cannabis lead to worse symptoms or were those with worse symptoms more likely to use cannabis?

At this time, we cannot support or recommend the use of cannabis as a potential treatment for PTSD.

Expand Content
Share this Section:
Is bright light therapy another potential treatment for bipolar depression?

Sit DK, McGowan J, Wiltrout C, Diler RS, Dills JJ, Luther J, Yang A, Ciolino JD, Seltman H, Wisniewski SR, Terman M, Wisner KL. Adjunctive Bright Light Therapy for Bipolar Depression: A Randomized Double-Blind Placebo-Controlled Trial. Am J Psychiatry. 2017 Oct 3:appiajp201716101200. [Epub ahead of print] PubMed PMID: 28969438.


There are limited treatment options for bipolar depression.

Some previous data have suggested that addition of bright light therapy to medications may be useful for the treatment of bipolar depression.

This randomized, controlled clinical trial aimed to evaluate the efficacy of bright light therapy as an adjunct to medication for the treatment of bipolar depression.


This was a 6-week randomized, double-blind, placebo-controlled trial.

Forty-six adults with either bipolar I or bipolar II disorder depression were enrolled.

Participants were required to be on adequate antimanic medication and patients with

hypomania or mania, mixed symptoms, or rapid cycling were excluded.

The concomitant medications were used by equal numbers of patients in the two groups.

In addition to existing medications, participants were randomized to receive either 7,000-lux bright white light or 50-lux dim red “placebo” light.

The light therapy was given at midday.

As another precaution against inducing hypomania, mania, or mixed symptoms, the bright light therapy was gradually titrated up over four weeks.


Participants were enrolled throughout the year but the time of enrollment was statistically controlled for. Due to small numbers, the study could not control for a seasonal pattern to the depression.

Patients treated with bright white light had a significantly higher remission rate (68%) compared to those who received the placebo light (22%). That’s a big difference!

The depression scores were statistically significantly less in those who received bright light therapy.

Most of the improvement occurred after four weeks of treatment.

No mood polarity switches occurred in either group.

Sleep quality improved in both groups and there was no statistically significant difference between the two groups.


Addition of bright light therapy to medication was found to be efficacious as a treatment for bipolar depression.

Clinical Commentary

Given the difficulty of treating bipolar depression, introduction of any new treatment options is most welcome. However, here are some caveats:

Previous studies disagree as to whether morning bright light therapy is effective for bipolar depression. So, the timing of the bright light therapy seems to be important and this needs further study.

It will be important to counsel patients that they must not give up on the bright light treatment without trying it for at least six weeks, preferably more.

The authors noted that given the trajectory of the response to bright light therapy, it is possible that there could have been even more benefit if the treatment had been continued for more than six weeks.

Since most health insurance plans are unlikely to cover the cost of a bright light therapy lamp, patients will have to be willing to pay for it out of pocket.

We must make sure that patients at increased risk of switching to mania are excluded and that adequate antimanic medication is in place before bright light therapy treatment is started.

Expand Content
Share this Section:
Does melatonin work for primary sleep disorders?

Auld F, Maschauer EL, Morrison I, Skene DJ, Riha RL. Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders. Sleep Med Rev. 2017 Aug;34:10-22. Review. PubMed PMID: 28648359.


Melatonin is being widely used for the treatment of primary and secondary sleep disorders. Clinicians often recommend it but patients can, and do, get it over-the-counter.

This meta-analysis aimed to assess the research evidence for the use of melatonin to treat primary sleep disorders.


A detailed search of the literature was done to identify published studies on this topic.

Studies were included if they compared the efficacy of melatonin to placebo in persons with primary insomnia, delayed sleep phase syndrome, non 24-hour sleep wake syndrome in people who are blind, or rapid eye movement-behavior disorder.

Only double-blind or single-blind randomized, controlled clinical trials were included.

Meta-analyses were done to combine the results of these studies.


Twelve studies met the inclusion criteria for this study.

Melatonin was found to be statistically significantly more efficacious than placebo in reducing the time to onset of sleep (sleep latency) in persons with primary insomnia or delayed sleep phase syndrome.

Melatonin was also statistically significantly more efficacious than placebo in regulating sleep-wake patterns in blind persons.

There is quite wide variation in the dose of melatonin used in different studies. Studies in primary insomnia typically used 1 to 2 mg of melatonin given 2 hours prior to bedtime. Studies for other indications tended to use higher doses.


Melatonin seems to be efficacious for treating certain primary sleep disorders.

Larger randomized controlled clinical trials of the use of melatonin in various sleep disorders are recommended.

Clinical Commentary

Use of melatonin is attractive not only because it is perceived by patients as “natural”, but also because it does not seem to be associated with any tolerance, dependence, hangover, or impaired alertness the next day.

It also does not appear to suppress rapid eye movement (REM) sleep.

We should note, though, that this safety of melatonin is only valid for short-term use and in adults. Concerns have been raised about the safety of melatonin in children and in long-term use.

One problem in recommending melatonin for routine use is the limited and contradictory data regarding the optimum dose. Fixed-dose comparison studies are needed to determine the optimum dose.

Expand Content
Share this Section:
Which interventions work for sensory problems in autism spectrum?

Weitlauf AS, Sathe N, McPheeters ML, Warren ZE. Interventions Targeting Sensory Challenges in Autism Spectrum Disorder: A Systematic Review. Pediatrics. 2017 Jun;139(6). pii: e20170347. Review. PubMed PMID: 28562287.


In DSM-5, atypical sensory responses have been included as a key diagnostic feature for the first time.

About 40% to 90% of children with autism spectrum disorder have abnormalities of sensory processing.

For example, children with autism spectrum disorder may have difficulties with bright lights or with certain clothing/ food textures/noises/colors. These difficulties may involve avoidance or the opposite—a fascination with a particular type of stimulus.

This paper aimed to systematically review the published research to determine which interventions work for the sensory problems of these patients.


A systematic search of the literature was done to identify relevant studies.

The data were then carefully extracted from those studies by using a specified methodology.


Twenty-four studies were included in this review. These included 20 randomized controlled trials.

The authors classified the interventions into five categories and found the following:

1. Sensory integration-based approaches

These interventions used combinations of sensory and kinetic components, e.g., materials with different textures, touch or massage, swinging and trampoline exercises, balance and muscle resistance exercises.

These interventions were found to improve sensory and motor skills-related measures.

2. Environmental-enrichment based strategies

These interventions used exposure to specific types of sensory stimuli to promote tolerance of similar stimuli in other situations.

They were found to improve nonverbal cognitive skills.

3. Auditory integration-based approaches

These used elements like filtered sound to help improve sensory processing. 

These interventions were not found to improve language.

4. Massage-based approaches

These used massage by a therapist or a caregiver.

These interventions were found to improve both general symptom severity and sensory challenges.

5. Music therapy

These studies used playing or singing music and/or movement to music.

The findings of these studies could not be synthesized because the methodologies of the different studies were too different.


Some interventions may lead to modest and short-term improvement in sensory and other symptoms of autism spectrum disorder.

However, the implementation of the interventions was not consistent, sample sizes were small, and follow-up was of a relatively short duration, so more research is needed to confirm and expand these findings.

It is not clear whether the benefits of these interventions would persist beyond a few months (the duration of the studies).

Clinical Commentary

Sensory dysregulation plays an important role in the symptoms and distress related to autism spectrum disorders.

In the absence of good research data, parents are frequently left to their own devices to figure out what might work.

This review suggests that while a lot more research is needed, the available evidence suggests that several non-pharmacological interventions can be helpful in improving specific symptom domains in children with autism spectrum disorders.

Given the absence of alternative treatments and the relatively benign nature of the interventions, in my opinion, use of these therapies should be encouraged even though more research is needed.

Expand Content
Share this Section:
Should older adults be encouraged to eat avocados?

Scott TM, Rasmussen HM, Chen O, Johnson EJ. Avocado Consumption Increases Macular Pigment Density in Older Adults: A Randomized, Controlled Trial. Nutrients. 2017 Aug 23;9(9). pii: E919. PubMed PMID: 28832514.


Lutein is a nutrient that is selectively taken up into the macula of the eye and into the brain.

Increased levels of lutein in the macula of the eye and in the brain are correlated with improved cognition in both younger and older adults.

Since lutein levels in the brain cannot be measured while the person is alive, macular pigment density is a useful biomarker of the amount of lutein in the brain.

Use of a lutein supplement was been shown to improve verbal fluency scores in older women in one previous study.

Lutein-containing foods include avocados, green leafy vegetables, squash, broccoli, and eggs.

Since avocados are a particularly bioavailable source of lutein, this study evaluated the effect of avocado intake on cognition in older adults.


This was a six-month, randomized, controlled clinical trial done in healthy older adults.

The subjects were randomized to consume one of the following foods every day:

1. One avocado (0.5 mg/day of lutein)

2. One potato (0 mg/day lutein)

3. One cup of chickpeas (0 mg/day lutein).

Groups 2 and 3 were Controls.

Serum lutein levels, macular pigment density, and cognitive ability (based on a computerized battery of cognitive tests) were evaluated at baseline and after three months and six months of consuming the respective foods.


After six months:

1. Serum lutein levels were increased by 25% from baseline in persons consuming avocados but they also increased by 15% in controls.

2. Macular pigment density increased from baseline in those consuming avocadoes but not in controls.

3. Memory and spatial working memory improved in both groups.

4. Persons consuming avocados showed improvement in sustained attention while controls did not.

5. The increase in macular pigment density was correlated with improved working memory and efficiency in approaching a problem.


Daily consumption of one avocado may improve some aspects of cognitive functioning in older adults.

Clinical Commentary

This was a small study with some methodological limitations (e.g., analyzing only those who completed the study, multiple statistical testing).

Nevertheless, the findings are interesting and may help clinicians answer dietary questions from their patients.

In my opinion, that the study was funded by the Hass Avocado Board and USDA does not by itself detract from the value of the study.

Much more research is needed, for example to determine the optimum daily dose of lutein and to compare the effectiveness of different lutein-containing foods.

Expand Content
Share this Section:

Rajnish Mago, MD
Medical Editor, GME Research Review

GME Research Review is a monthly newsletter edited by Rajnish Mago, MD, who is author of "The Latest Antidepressants" and "Side Effects of Psychiatric Medications: Prevention, Assessment, and Management." Dr. Mago selects, summarizes, and provides a clinical commentary on the latest published research in psychiatry. 

We are always carefully evaluating which research papers to discuss in GME Research Review. Have come across a research paper published in the last 6 months that you thought is clinically relevant? Do you want me to analyze it for you and for the benefit of others? Please email Dr. Mago the citation at [email protected].

To contact GME, email us at [email protected]

GME does not provide medical advice. The website and articles are intended for informational purposes only. They are not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the GME Website. If you think you may have a medical emergency, immediately call your doctor or dial 911.

Log In

Join GME For Free

Become a GME subscriber and gain full access to our extensive library of 700+ psychiatric medical education videos, free CME webcasts, latest research updates, and more. To sample our content, watch the featured videos below.
Join Today!