Lifetime risk of any mental disorder ≈ 50%.

There are 2 statements which might  look conflicting:
 

"1 in 5 children born today will suffer from a serious mental disorder in their lifetime."

 and

"~50% of the population will personally experience such a disorder in their lifetime."

The terminology for — “someone will suffer from a serious mental disorder in their lifetime” — is lifetime risk or lifetime prevalence. 

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✅ Clarifying the Two Statements:

1. "1 in 5 children born today will suffer from a serious mental disorder in their lifetime."

→ This is referring to serious (severe) mental disorders only.

• This includes schizophrenia, bipolar I disorder, severe major depression, severe autism, etc.

• These are typically disabling or persistent disorders with high functional impact.

• Lifetime risk ≈ 20% is a rough estimate for these serious conditions.

2. "About 50% of the population will experience a mental disorder in their lifetime."

→ This refers to any diagnosable mental disorder, including:

• Mild to moderate depression or anxiety

• Adjustment disorders

• Substance use disorders

• ADHD, phobias, eating disorders, etc.

• Many are episodic, mild, or self-limiting.

• This is based on epidemiological studies like those from NIMH or Global Burden of Disease studies.

• Lifetime prevalence of any mental disorder ≈ 46–50%.

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🔍 So why the difference?

Because they are talking about different levels of severity:

Metric	What It Refers To	Prevalence
20% ("1 in 5")	Serious mental disorders	~20% lifetime
50%	Any mental disorder (mild to severe)	~50% lifetime

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✅ Which is correct?

Both are correct, depending on context:

• Use "50%" when you mean all mental disorders (broad definition).

• Use "20%" if your Petition is focused on serious, preventable suffering (e.g., disabling conditions).