Why does mental illness usually manifest in young adults?

The real answer is that the doctors don’t know the answer.

Just hypothesizing here:

Probably, at least partly, it’s hormones and stress and also a build up of life experiences.

Plus, adolescence is when certain behaviors become less acceptable, and if they persist, it’s easier to diagnose the problem.

I remember right before my dad retired they were designing a study regarding ADD medication. They were thinking that possibly some children don’t respond well to medication because the diagnosis is incorrect and maybe they are actually bipolar.

Maybe imaginary friends get realized to be actual hallucinations, because most children outgrow an imaginary friend. Possibly, the child always was hallucinating. Although, it seems that in many people it does start in adolescence.

I think so many things affect our brains and mental health. It’s so complex that I doubt there will ever be one single answer.

Too many fret too much about getting laid.

^^Male answer. Oy.

Good question, and as @Hawaii_Jake says there may not be a clear answer yet.

But at least one large study of over 190 research reports suggests that early onset of some types of mental illness might be related to the rapid development of the human brain through late adolescence into early adulthood.

https://www.nature.com/articles/s41380-021-01161-7

Basically there is so much exponential nuerologic development happening in such a brief period of time that the odds of at least a short-term disorder may increase.

I’m just guessing, but I’d say it’s because young adulthood is when symptoms first show up. By the time someone is in their 40’s or older, they’ve already had issues and their problems have come to the attention of various people and probably been treated. If there is a predisposition to mental illness, the stressors of late teens/early adulthood are likely to cause the symptoms to be manifested.

This is a good article:

https://www.vice.com/en/article/xd7g44/why-mental-health-disorders-emerge-in-your-early-20s-58477fa6e17bea0210307264

and another one:

https://www.nbcdfw.com/news/health/the_real_world__recognizing_mental_illness_in_young_adults/2112996/

I have to wonder if “mental illness” is just a catch-all phrase. Young adults are still figuring things out. They have to often learn through trial and error, whether it be through physical or mental actions. They have to establish who they are. A child has a brain that is not acting like an adult feels it should or that child is showing behavior that seems off so the child is taken to a doctor or a psychologist who goes on to medicate the child so they will not think/act that way and they call it mental illness.

There is a reason children stop being children as they get older. They make the move where they are allowed to play and grow and explore into a role where they are mature with a better understanding of how to fit into society. But as they make that move, their behavior/thinking can be a bit odd. Our society rushes to call it mental illness.

Young people don’t hide their emotions. Older adults have become adept at hiding their symptoms. It might still be there, but they just don’t allow you to see it!!!

I think it’s there much younger but not diagnosed until later. This is of course, a complicated question that we don’t have answers to.

A good guess would be a combination of hormone imbalances initiated with puberty combined with a natural tendency to assign all societal aberrations of personality when observed in children as mere products of immaturity. Ask yourself, for example, at what age it should be acceptable for a president to uniformly manifest the behaviors and mindset of a 3 year old?

Some of it is probably that as a teen, the family unit is somewhat compensating— supporting healthy behaviors and possibly avoiding situations that trigger negative behaviors. Manageable and therefore undiagnosed conditions can spiral out of control when those supports are gone.

Update I was wondering if it is the age that one has to be more self reliant, and to stand on their own two legs. Then they fail, for the first tine without much help from schools and parents.

@RedDeerGuy1 please see the answer by JLoon above.

@Hawaii_Jake I have problems reading her link. Too many stats.

^I think the key point is that there is a great deal of brain development during that time, so the illnesses come out.