Adolescence to Adulthood: Defining the Transition

The transition from adolescence to adulthood is marked by:

• Completion of somatic growth (epiphyseal closure, peak bone mass).
• Attainment of reproductive maturity (regular cycles, spermatogenesis).
• Neurodevelopmental maturation (prefrontal cortex myelination into mid-20s).
• Psychosocial milestones: Autonomy, identity formation, economic independence.

Chronologically, this typically occurs in the late teens to early twenties, but varies individually and culturally. Legal adulthood (18–21) does not equate to biological or psychological maturity.