Are there clear, identifying characteristics of the “abnormal timing of developmental events” that can lead to schizophrenia, psychosis, ADHD, etc.? How can parents know if their child has experienced this abnormal development?

Q. Are there clear, identifying characteristics of the “abnormal timing of developmental events” that can lead to schizophrenia, psychosis, ADHD, etc.? How can parents know if their child has experienced this abnormal development?