People think that phones are bad for anxiety. Parents think phones are bad for the mental health of children. What is the truth? I felt I had to get to the bottom of the relationship between phones and anxiety while I was writing my book You Don't Understand Me, which addresses the mental health of teenage girls and young women. It doesn't look great. There has been a decline in the mental health of young people since the invention of the phone. correlation doesn't necessarily equal causation

I have observed that phones act as a catalyst to our emotions rather than being the cause of the problem. This can be a positive thing, when it allows us to connect with friends and family. It allows marginalized communities to meet each other.

Humans are wired to anticipate danger and our minds can quickly create catastrophic, wholly imaginary circumstances, which our bodies respond to as though they are true. Some of my friends don't want me there, they don't really like me, and nobody really likes me.

There are a number of ways in which the phone contributes to this. It allows us to know that our friends are meeting. ignorance is bliss now, and there was something there. We know, and we get to sit on our sofa in some old jogging bottoms on a Saturday night and compare our inside worries, our worst sides, our ugliest self, with endless versions of other people's lives. And guess what? That makes us sad.

We shouldn't pick our phone. We know it is making us feel bad seeing our friend on a weekend trip away with her gorgeous partner, and we know we should take a walk, yoga, and a hot bath. No one wants to hang out with you if you have a perfect bathroom and a beautiful body on social media. Your phone can cause a second round of self-judgment about how lazy or worthless you are.

The phone intensifies a comparison culture that can leave you feeling not good enough in every single aspect of life

The phone can make you feel like you aren't good enough in many aspects of life, such as being thin, successful, organised, and well-read.

While research into the effects of this on mental health is in its infancy, there is particularly damning research in relation to viewing photos of perfect bodies, which is shown to increase body dissatisfaction with a link to eating disorders. Even if we know the images are doctored, they still impact on body dissatisfaction.

Some of the questions I ask my patients are related to their phone use.

Do you use your phone to connect with people or to compare people? The latter is positive for mental health but will likely increase anxiety.

Is there a tipping point where phone use goes from positive to negative? Do you notice the change? Is it possible to put your phone away? The phone is at its most magnetic at this point, according to my experience.

Is your phone making it hard for you to do things that are positive for mental health? It's important for wellbeing that phone use doesn't get in the way of sleeping, eating, being outside and moving your body.

Research suggests there may be a sweet spot with mobile phone use, after which the screen stops being helpful and starts having a negative impact

There may be a sweet spot with mobile phone use, after which the screen stops being helpful or fun, and the negative impact on wellbeing begins. A couple of glasses of red wine can be relaxing, but a bottle a night is not so helpful. Some people find it hard to stop drinking when they should.

Think about how much time you spend on your phone and what kind of content it is, if you are experiencing anxiety. It is possible that dressing this could be an important key to a less anxious life.

It's best to use phone and internet in line with our other values rather than taking us away from them. I would look for phone use which is driven by:

It's connecting to people. A shared family group can be great. This isn't the same as looking out for ex-schoolmates to see how successful they are.

For yourself. An online yoga class, meditation app or audiobook are examples of ways to use the internet. Watching back-to-back episodes of a box set into the night is not compassionate, it is getting in the way of self-care of sleeping.

There is creativity. The phone has allowed a democratisation of creativity, particularly in photography, but also in sharing humour, craft, art and writing. Teenagers have shown incredible creativity on platforms such as TikTok, but we need to be careful with the content that is related to beauty or sexuality.

There is a curiousity about the difference. A small disagreement can turn into a massive row with the help of a phone. Is it possible to use your phone to explore new ideas?

You Don't Understand Me: The Young Woman's Guide to Life is available at guardianbookshop.com.