Anxiety, depression and post-traumatic stress disorder (PTSD) are among the most common mental health conditions for which Australians are prescribed medicinal cannabis.

Most prescriptions for mental health conditions, and for other conditions more broadly, are for products containing higher levels of THC (tetrahydrocannabinol). This is the part of cannabis that causes a “high” and can affect thinking and mood.

Many of these prescriptions are for inhaled products, such as dried leaf or flower that people smoke or inhale.

This pattern of use – of inhaled, higher-THC content for mental health conditions – appears to be partly driven by prescribing trends among 18 to 44-year-old men.

For anxiety alone, there are almost three times more approvals for the products containing the highest levels of THC than for products containing only CBD (cannabidiol).

But this prescribing pattern doesn’t line up with the best available research. Most higher-quality clinical trials for anxiety have tested CBD-based products, not THC.

This is just one example of how Australians are using medicinal cannabis to treat mental health conditions without the best available evidence to back it.

Let’s start with anxiety

Anxiety is the most common mental health reason people seek medicinal cannabis in Australia.

There is emerging evidence CBD may help some people with anxiety, but the findings are inconsistent.

The largest and most comprehensive systematic review on medicinal cannabis and mental health found it did not meaningfully improve anxiety symptoms. The authors said we still need larger, high-quality trials, and studies that reflect how people use medicinal cannabis in the real world.

Evidence for THC is even more mixed. In our previous article we described how some people find THC makes them feel calmer, but others say it worsens their anxiety. As few trials have investigated THC for anxiety, it is hard to draw firm conclusions.

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Medicinal cannabis prescriptions have skyrocketed in Australia, mostly for legal but unapproved products we don’t even know work or are safe. In this series, experts tease out what’s fuelling the rise of medicinal cannabis, the fallout, and what needs to happen next.

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How about PTSD?

The evidence so far for using medicinal cannabis to treat PTSD is limited.

While some people report benefit, the findings from the small number of high-quality randomised controlled trials (the gold standard for medical evidence) are mixed.

In one very small study, only five people completed the entire protocol. This tested vaporised cannabis containing either a combination of 10% THC and 10% CBD, or a product with mainly 10% THC.

Both products appeared to improve PTSD symptoms in the short term, but the trial had trouble recruiting participants. A larger study would be needed to know if the results are reliable.

Another trial tested smoked cannabis with three strengths: 12% THC, one mainly containing CBD, and one with equal amounts of THC and CBD. There was no change in the severity of PTSD symptoms for any of the products compared to placebo. Smoking cannabis, including medicinal cannabis, is also not recommended because of its well known harms.

The limited and uncertain evidence is one reason the Department of Veterans’ Affairs has decided not to fund medicinal cannabis to treat mental health conditions, including PTSD.

What about depression?

There is even less high-quality evidence for using medicinal cannabis to treat depression. A recent systematic review found no relevant randomised controlled trials.

A small pilot study tested 150–300 milligrams a day of CBD alongside standard treatment for bipolar depression. CBD was well tolerated, meaning it didn’t cause serious side effects, but it didn’t help symptoms.

Studies for different types of depression are mixed. Some show possible benefits but also unfavourable effects including worse symptoms or acute mental health effects such as psychosis, suicidal thoughts or anxiety. It is also unclear whether unfavourable effects are due to the product or underlying mental health condition.

Is medicinal cannabis safe?

Emerging evidence shows psychosis has been reported among people using medicinal cannabis containing higher levels of THC.

Australia’s medicines regulator, the Therapeutic Goods Administration (or TGA) says products containing THC are generally not appropriate for people who have a personal or family history of psychosis or schizophrenia. This caution also extends to people with past or current mood or anxiety disorders.

This is largely because THC can worsen or trigger symptoms in people who are already vulnerable to these conditions.

Why the increased risk?

Is this due to the THC or were these people already at higher risk? It’s likely a mix of both.

Daily or near-daily cannabis use (which is common with medicinal use) is linked to a higher risk of psychosis, or it may contribute to developing it.

Young people may be particularly vulnerable to side effects after taking medicinal cannabis (and cannabis in general) for mental health conditions as their brains are still developing.

Other research shows higher-strength THC products appear to carry higher mental health risks for everyone. People who use frequently, or for long periods, are at further risk.

So the emerging picture is that the product used, how it is used, and the person matter and can influence health outcomes. Higher THC products raise risks across the board, but those risks are increased in people who start young, use often, or continue long term.

What happens when I stop taking it?

Some people whose mental health symptoms increase when they stop taking medicinal cannabis see that as evidence their medicine was working. But that’s not necessarily the case. They could be experiencing withdrawal from cannabis.

Many people who use cannabis (medicinal or otherwise) experience a rebound in symptoms – such as anxiety or sleep difficulties – when they stop. This can feel very similar to the symptoms that prompted them to seek treatment.

We also know around one in three or four people who use cannabis medically will develop cannabis dependence and are likely to experience withdrawal symptoms if they stop using it suddenly.

So, cannabis withdrawal may be more common than people realise, and may well explain symptoms that emerge when someone stops taking it.

How do I know what is right for me?

Many studies that look at whether medicinal cannabis could help different mental health conditions are low quality or have conflicting findings. So the evidence is not yet strong enough to recommend it as the best treatment for any mental health condition.

So talk to your trusted, regular medical professional to help you weigh up the potential benefits and risks of medicinal cannabis, especially if you have a history of mental health concerns.

Given the mixed evidence and the TGA’s cautions, it’s really important to seek personalised medical advice.

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If you or someone you know is struggling with anxiety, mood changes, or any mental health concerns – whether or not these relate to cannabis use – the following support is available: Beyond Blue (24/7 support): 1300 22 4636 and Lifeline (crisis support): 13 11 14.

Suzanne Nielsen, Professor and Deputy Director, Monash Addiction Research Centre, Monash University and Myfanwy Graham, NHMRC Postgraduate Scholar and Fulbright Alumna in Public Health Policy, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bushfires are currently burning in Australian states including Victoria, Tasmania, Western Australia and South Australia. In some areas, fire authorities have warned residents about the presence of smoke.

Bushfire smoke is harmful to our health. Tiny particles of ash can lodge deep in the lungs.

Exposure to this type of smoke may worsen existing conditions such as asthma, and induce a range of health effects from irritation of the eyes, nose and throat to changes in the cardiovascular system.

Public health recommendations during smoke events tend to provide general advice, and don’t often include advice specifically geared at children. But children are not just little adults. They are uniquely vulnerable to environmental hazards such as bushfire smoke for a number of reasons.

Different physiology, different behaviour

Children’s lungs are still developing and maturing.

Airways are smaller in children, especially young children, which is associated with greater rates of particle deposition – when particles settle on the surfaces of the airways.

Children also breathe more air per kilogram of body weight compared with adults, and therefore inhale more polluted air relative to their size.

Further, children’s detoxification systems are still developing, so environmental toxins take longer to effectively clear from their bodies.

Meanwhile, children’s behaviour and habits may expose them to more environmental toxins than adults. For example, they tend to do more physical activity and spend more time outdoors. Higher levels of physical activity lead to more air inhaled per kilogram of body weight.

Also, a normal and important part of children’s early play is exploring their environment, including by putting things in their mouth. This can result in kids ingesting soil, dust and dirt, which often contain environmental contaminants.

For these reasons, it’s important to consider the specific needs of children when providing advice on what to do when there’s smoke in the air.

Keeping our environments healthy

The Australian government offers recommendations for minimising the health risks from exposure to bushfire smoke. The main advice includes staying indoors and keeping doors and windows closed.

This is great advice when the smoke is thick outside, but air pollutants may still accumulate inside the home. So it’s important to air your home once the smoke outside starts to clear. Take advantage of wind changes to open up and get air moving out of the house with a cross breeze.

Kids are natural scientists, so get them involved. For example, you and your child can “rate” the air each hour by looking at a landmark outside your home and rating how clearly you can see it. When you notice the haze is reducing, open up the house and clear the air.

Because air pollutants settle onto surfaces in our home and into household dust, an easy way to protect kids during smoky periods is to do a daily dust with a wet cloth and vacuum regularly. This will remove pollutants and reduce ingestion by children as they play. Frequent hand washing helps too.

Healthy bodies and minds

Research exploring the effects of bushfire smoke exposure on children’s health is sparse. However, during smoke events, we do see an increase in hospital visits for asthma, as well as children reporting irritation to their eyes, nose and throat.

If your child has asthma or another medical condition, ensure they take any prescribed medications on a regular schedule to keep their condition well controlled. This will minimise the risk of a sudden worsening of their symptoms with bushfire smoke exposure.

Make sure any action plans for symptom flare-ups are up to date, and ensure you have an adequate supply of in-date medication somewhere easy to locate and access.

Kids can get worried during bushfires, and fire emergencies have been linked with a reduction in children’s mental health. Stories such as the Birdie’s Tree books can help children understand these events do pass and people help one another in times of difficulty.

Learning more about air pollution can help too. Our group has a children’s story explaining how air pollution affects our bodies and what can help.

It’s also important for parents and caregivers not to get too stressed, as children cope better when their parents manage their own anxiety and help their children do the same. Try to strike a balance between being vigilant and staying calm.

What about masks?

N95 masks can protect the wearer from fine particles in bushfire smoke, but their use is a bit complicated when it comes to kids. Most young children won’t be able to fit properly into an N95 mask, or won’t tolerate the tight fit for long periods. Also, their smaller airways make it harder for young children to breathe through a mask.

If you choose to use an N95 mask for your children, it’s best to save them for instances when high-level outdoor exposure is unavoidable, such as if you’re going outside when the smoke is very thick.

N95 masks should be replaced after around four hours or when they become damp.

If your child has an existing heart or lung condition, consult their doctor before having them wear an N95 mask.

Our team is currently recruiting for a study exploring the effects of bushfire smoke in children. If you live in south east Queensland and are interested in participating in the event of a bushfire or hazard reduction burn near your home, please express your interest here.

Dwan Vilcins, Group leader, Environmental Epidemiology, Children’s Health Environment Program, The University of Queensland; Nicholas Osborne, Associate Professor, School of Public Health, The University of Queensland, and Paul D. Robinson, Conjoint Professor in Respiratory and Sleep Medicine, Child Health Research Centre, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.