Anxiety is at record highs among teens and young people. What's driving this spike in mental health struggles? Experts have pointed the finger at everything from phones to politics to helicopter parenting. But while the exact causes of the worrying increase in anxiety are still being debated, one thing is clear: Parents' over-the-top stress about their kids' future isn't helping. 

In a world where those with a college degree not only significantly outearn those without one, but even outlive them by a startling eight-and-half years on average, it's entirely natural that entrepreneurs would be anxious about their kids' academic achievements. But research shows that the more we stress about our kids' grades, the more miserable they grow. 

"I have for years thought that one of the main causes of the increase in adolescent depression was an increase in school pressure," Laurence Steinberg, a psychologist who studies teens, told the Atlantic. "When I talk to kids and we talk about sources of stress, they mention school pressure more than likes on Instagram."​

So how can success-focused parents modulate their interest in their kids' performance so that they hold them to high standards but don't drive them towards mental health struggles? Journalist, Harvard grad, and parenting researcher Jennifer Breheny Wallace has a suggestion -- justchange what you ask your kid when they walk through the door after school every day. 

"Lead with lunch"

Breheny Wallace is the author of the new book Never Enough: When Achievement Pressure Becomes Toxic -- and What We Can Do About It, which is based on a survey of 6,500 parents she conducted along with Harvard researchers.She recently spoke to CNBC about what she learned from the project, and offered one simple change parents can make to help protect their children's mental health. 

Like many parents, she told CNBC, as soon as her kids came in the door, she used to pepper them with questions about school. How did that quiz go? What homework do you have? Are you ready for that big math exam at the end of the week? Now, she "leads with lunch" instead.  

"When my kids come in the door, instead of asking them, 'How'd you do on the Spanish quiz?' -- which I used to do before I wrote the book -- I now ask them, 'What did you have for lunch?'" she tells the site. "I talk about things that have nothing to do with their achievements."

Whether your child opted for a bologna sandwich or the chicken fajitas is, of course, not wildly important. Why make the shift then? Psychologists repeatedly told Breheny Wallace not only that parents' achievement anxiety is catching, but that when parents always lead with schoolwork-related questions, kids learn that what their parents really care about is their achievements, not them. 

If you let how your kid did on the Spanish quiz instantly color your interactions with them, they come to understand that your love and esteem are contingent on grades. And that, Breheny Wallace insists, can lead to toxicity, anxiety, and mental health struggles. 

But wait, don't I need to know how my kid is doing in Spanish? 

While few parents intend to send their kids this message, I can imagine some would still question to Breheny Wallace's lunch-first gospel. Shouldn't parents be involved in their kid's schooling and support their success? Of course, she responds, but parents need to press their kids less to share about these topics than they think they do, she insists. 

"My kids are going to tell me. It's on their minds," she says of academic matters. "They don't have to think that I've been worrying all day about one Spanish quiz. Instead, they should be getting the messaging from me that I care about them as a whole person."

Breheny Wallace does sometimes initiate conversations about academics and future plans, but she now follows the advice of psychologists and saves these talks for a single allotted hour on the weekend rather than letting them color just about every parent-kid interaction. The result, she says, is kids who understand how much she values academic achievement and hard work but know that her love for them isn't tied to any particular outcome. And that is certainly a big step toward protecting kids from anxiety and mental health struggles.