The term adolescence denotes the period of time between the onset of puberty and the completion of physical maturation. During these transitional years, full reproductive capacity is attained, manifested by spermatogenesis in the male and ovulation in the female. Concomitantly, major physical changes occur, including (1) full maturation of the gonads, external genitalia, and secondary sexual characteristics, (2) alterations in lean body mass and fat distribution, and (3) rapid skeletal growth, ultimately terminated by fusion of the epiphyses and the attainment of final adult stature.
Although we are accustomed to equating adolescence with the teenage years, the last century has been characterized by a progressive lowering of the normal age for pubertal development, so that presently, 50% of girls in the United States reach puberty while in elementary school. The implications of this earlier physical maturation, particularly in terms of sexual education and contraception counseling are readily evident. Furthermore, as the normal onset of puberty occurs earlier, the psychological ramifications of pubertal delay and short stature in adolescence become increasingly pronounced. It is not unusual, nowadays, to see 13 or 14-year-old patients (and their parents) who are concerned about delays in sexual maturation and skeletal growth, and while the majority of such patients are found to be normal variants, their anxieties and concerns are nonetheless real.
Puberty and social brain development
