Does too much screen time time lead to dementia?

Excessive screen time might contribute to increasing dementia likelihood 4-6 times in the next decades, a new study claims.

The authors use existing US public data and past research to make predictions about brain health and society.

The study tries to understand two main things:

1) How screen time (phones, TV, computers, tablets) affects the brain

2) How dementia rates might change in the future as a result

They say that dementia/Alzheimers is impacted by two factors - screen time and declining IQ. 

Official CDC health data already suggests that dementia cases will rise x2 as the population gets older. However, authors argue real increase could be much higher, 4-6 times in later decades, as current models underestimate screen time.

Existing research shows that high screen use may be linked to less attention and focus, weaker memory skills, more stress and anxiety, poor sleep, less physical activity - all of these factors have been shown to affect the brain health. They also coincide with symptoms of mild cognitive impairment, which is a precursor to dementia. Heavy screen use during childhood may also affect brain development. 

This study also talks about a reported “reverse Flynn effect.” In some data, average IQ scores may be slightly declining in recent decades since the generation born in 1975 (peak of IQ). The authors suggest this could be linked to environmental and lifestyle changes, as well as increased screen use.

So how is it related to dementia? The authors use the idea of “brain reserve.”

This means that a stronger, healthier brain may resist dementia longer, while a weaker brain may be more vulnerable. Less learning, less deep thinking, and more passive screen use could reduce brain reserve --> increase dementia risk later in life.

As Millennials and Generation Z use screens more than older generations, and their IQ is declining, authors suggest they might be more affected in the long term. It means far higher public health spending on brain-related diseases.

Important: the study does not state/prove that screen time causes dementia, but shows correlations and secondary weakening effects that it may have on the brain health. We do need longitutidnal studies to prove it. Developing healthier digital habits early in life might be a good prevention strategy while we are still looking at long-term studies. 

If you want to know more about this topic and relationship between health and our screens, check out CDI's certification in digital wellbeing.