Norman Swan: Over the last week the ABC has been focusing on your mental health and offering practical evidence-informed advice on what we can all do to get through this COVID-19 pandemic as best we can. So what role could laughter play? There is nothing new about the idea of using laughter as a mood booster. Even the King James Bible preaches that 'a merry heart doeth good like a medicine'. But can laughter therapies really help alleviate the stress, anxiety and depression that many of us are experiencing right now?

The Health Report's David Murray has been investigating.

David Murray: Chances are you probably don't feel much like laughing right now. But maybe in this moment, laughter is exactly what we need more of.

Dan Illic: Laugh at the pandemic, at the way we are all living due to the pandemic. If you don't, you actually might cry.

David Murray: Dan Illic is a satirist and comedy writer. If you got a chuckle out of watching Ray Martin on At Home Alone Together, well, you can thank Dan for bringing you that. And he reckons that right now people really want something to laugh at.

Dan Illic: I must have seen five or six live streams by comedians from their own living rooms. Some of them had audiences between 60 and 300 people on Zoom, and that's incredible. Also there is so much great comedy happening on Instagram and TikTok, incredibly funny stuff, impersonating world leaders, making fun of the restrictions. It ends up being able to dissolve tension, absorb much of the fear around the world we are living in in this pandemic land right now.

David Murray: Comedy is great, obviously, but sometimes it's just as likely to elicit a groan as it is a giggle. So what about laughter itself? We are often told it's the best medicine, but can it get us through this pandemic with our mental health intact?

This is a laughter therapy session. Usually it would be held in person, but just like everything else during the pandemic it has also gone online.

Ros Ben-Moshe: I felt very enlivened, a real elevation in my spirit.

David Murray: Ros Ben-Moshe is an adjunct lecturer in health promotion at La Trobe University. She also runs laughter well-being programs, sometimes called Laughter Yoga.

Ros Ben-Moshe: There are two different types of laughter therapy. There is a humour-based laughter therapy, so that's something that we would get from laughing together with friends or at a funny video, then there is non humour based laughter therapy which is where Laughter Yoga comes in.

David Murray: So, no jokes, no comedians, you just laugh.

Ros Ben-Moshe: The way that it works is the facilitator demonstrates a particular laughter exercise, so it might be a greeting laugh, like [laughs]. Initially that might seem a little silly or strange to people but people just lose themselves to laughter very, very soon.

David Murray: Basically this kind of Laughter Yoga relies on fake laughter, at least at the beginning. But studies have still linked it to the release of endorphins, the dilation of blood vessels, relaxing tense muscles, forcing you to breathe and kind of leaving you feeling like you've just done some exercise. It all sounds pretty good, but is this kind of laughter really the best medicine if you need a bit of help with your mental health?

Natalie van der Wal: I have to be honest, it started because I am a yoga teacher for many years.

David Murray: Natalie van der Wal is an Associate Professor in Cognitive and Social Psychology at Leeds University in the UK. Recently she has been looking into the research on laughter therapies and what the available studies actually say about laughter and its potential for alleviating stress, depression and anxiety. But she is the first to admit that when she started the project she wasn't exactly impartial.

Natalie van der Wal: A friend of mine, he's a Laughter Yoga leader, and I did a course with him to become a Laughter Yoga leader myself. So in the beginning I was little bit biased, but then my co-author, Robin Cok, he is actually super-critical, so my initial positive outlook got very realistic.

David Murray: Associate Professor van der Wal and her co-author collected 86 relevant studies across both humour and non humour based laughter therapies. I have to say that overall they weren't exactly impressed with the quality of the research. They say many studies didn't use control groups and relied on small sample sizes. Others showed a high risk of bias. And then there was the results on the efficacy of the therapy itself, which were, well, a bit mixed.

Natalie van der Wal: We found that laughter therapy significantly reduces your depression, that was the strongest outcome, but there were a little bit more mixed results for anxiety and stress. So there I cannot say as a scientist there is a real effect. It looks like it but I cannot say for 100% sure.

David Murray: Now, the reason for this comes down to statistics. I know, I know, stay with me here. Many of the studies included in this meta-analysis did conclude that laughter therapy helped reduce stress and anxiety. But according to Natalie van der Wal, when you look beyond the averages and include their confidence intervals (this is the range of values that you are fairly sure your true result lies in), then the positive effects for stress and anxiety potentially disappear.

Natalie van der Wal: You would really want to see that the complete confidence interval is below zero, and that is not the case for the majority of the studies.

David Murray: But here's the other interesting thing, while you might assume that natural organic laughter would be better for you, it was the non humour based therapies that had the greater effect on mental health. Ros Ben-Moshe says this could be because when you are not waiting for something to make you laugh, you actually laugh more. But does this really matter when the overall evaluation of laughter therapy studies was kind of disappointing? Well, Associate Professor van der Wal said we shouldn't be giving up on the idea of laughter as medicine just yet.

Natalie van der Wal: For me it's simple; if you laugh, you feel better. But if we have more research, like big large randomised control trial studies, then we can have a final say about it. At the moment we just don't have enough evidence.

David Murray: So in the meantime if laughing makes you feel better, go for it. While we can't say it's necessarily the best medicine, it certainly can't hurt.

Norman Swan: A bit of laughter there from the late southern gospel singer George Younce, finishing that report from David Murray.

More here:

Is laughter really the best medicine? - Health Report - ABC News