Since mental maturity of the mind only finishes at age 24, can any mental illnesses present throughout puberty gravely affect future mentality? I heard that children and teenagers shouldn't watch violent R-rated movies because their mental maturity may go in the wrong direction. If someone has ADHD, Schizophrenia or Maladaptive Daydreaming Disorder would the same thing probably happen? I have some psychological disorders myself, and I'm worried I might develop and grow up with them until adulthood.
It is a fact that a number of psychological disorders arise or become noticeable when a person reaches adolescence. I suspect that this is due to the brain rewiring itself for adult thinking. Problems become more noticeable during the extremes of the teenage years.
It is by 24 or 25 that the majority of guys have fully developed mentally. Many actually complete the changes earlier, but by 24 you can be fairly certain it is done.
During adolescence, it is very easy to become obsessive or develop compulsive behaviors. Usually a person grows out of them, but it is far to easy for things to get locked into place during the teenage years. That is why addictive substances, such as alcohol and tobacco, are kept from teens. It is also why we try hard to keep teens away from pornography. It isn't that these habits can't be broken, but habits established in adolescence are stubborn to let go.
Also because the brain is changing, chemicals that affect the brain can easily cause permanent damage. We've only recently learned that marijuana will temporarily lower the IQ of an adult, but will permanently lower the IQ of a teenager.
You have to realize that psychology is not nearly an exact science. We are still learning how the brain works and what affects it. Worse, psychology, being a science, doesn't know how to deal with unquantifable things like the human spirit. When there isn't a physical cause known for a problem, people fall back to treating the symptoms blindly.
Even what should be considered normal variation in behavior is hard to quantify. There are a number of people who think most of the ADHD labeling is being applied to normal boyish behavior. The fact that so many boys outgrow ADHD seems to lend credence to that belief.