Pubertal Maturation

Early and Late Pubertal Maturation

File photo | Credit: FatherlyOpens in new window

Early Maturation

Variations in the environment have been linked to variability in pubertal timing. Some of these findings have surprised researchers because the exact mechanisms by which environments “speed up” or delay pubertal onset are unknown. For instance, family composition can exert important effects on timing.

Consequentially, girls who grow up in homes where the father is absent or who are physically or sexually abused in childhood tend to reach puberty earlier in life. One explanation for these findings is that girls in these environments experience greater stress than girls who are not in these circumstances.

Stress leads to the release of a hormone called cortisol and to the activation of the hypothalamic-pituitary-adrenal (HPA) axis, which influences all hormonal secretions.

Another argument is based on Life History theory, which posits that the timing of reproductive readiness (i.e. pubertyOpens in new window) is tied to the environment in order to optimize the chance for reproductive success (Belsy, Steinberg, and Draper, 1991). The rationale is as follows: individuals reared in harmful or unpredictable environments (e.g. uncertain resources, high mortality rates, father absence) may have attempted to increase their reproductive success by accelerating sexual maturation and beginning sexual activity and reproduction at a relatively earlier age.

A shortened reproductive timetable in this context may have increased the probability of having at least one offspring that would survive and reproduce (Ellis, 2013).

In contrast, individuals growing up in a relatively stable and supportive environment would increase their reproductive success by maturing on time or delaying reproductive maturation, within a biologically acceptable range, in order to reap the benefits of an extended period of development (Ellis, 2004).

In such environments, deferring reproduction would allow individuals to acquire the sociocompetitive skills and resources necessary for successful mating and subsequent high-quality parental investment in offspring (Ellis, 2013).

Late Maturation

Most (approximately 95%) girls and boys have commenced puberty by 13 years and 14 years respectively. However, there are examples of youth passing the normal age range for puberty without showing any signs of body changes.

• In girls, delayed puberty is defined as lack of any breast development by age 12 – 13 years, lack of pubic hair by age 14 years, lack of menarche by age 16 years, or greater than 5 years between initial breast budding and menarche.
• In boys, puberty is considered delayed if testicular enlargement does not occur by 14 years of age, there is lacke of pubic hair by age 15 years, or more than 5 years are required to complete genital enlargement.

Puberty can be delayed for several reasons. Usually, youth who undergo delayed puberty are simply following a family pattern of delayed puberty that can be traced back to genetic underpinnings in the timing of puberty, a phenomenon known as constitutional delay of puberty (CDP) (or more colloquially as being a “late bloomer”).

In other circumstances, delayed puberty occurs because of diet and physical activity.

Girls’ bodies require a certain amount of fat before they can go through puberty or get their first menstrual period. It is for this reason that girls who suffer from food restrictive eating disorders, such as anorexia nervosaOpens in new window, also typically sexually mature later relative to their peers.

In addition to the relatively lower body fat, anorexia is associated with a hypogonadotropic state that can delay or arrest the onset of puberty (Warren and Vu, 2003) because of aberrant hormone levels.

Individuals with anorexiaOpens in new window and bulimiaOpens in new window (an eating disorder characterized by binge eating that is followed by vomiting or fasting, learn more) display elevated levels of the androgen hormones DHEA and DHEAS (Monteleone et al., 2001) and decreased levels of luteinizing hormone, FSH and estradiol (Devlin et al., 1989), which are all necessary for normative development of primary and secondary sex characteristics. These variations in hormone levels contribute to atypical pubertal timing.

Delayed puberty may also be caused by a medical condition. These include chronic illnesses, such as kidney disease, severe asthma, cystic fibrois, rheumatoid arthritis, celiac disease, or hypothyroidism.

Deficiencies in the production of gonadotrophins (FSH and LH) from the pituitary gland or in the production of sex steroids (estrogens and testosterone) can also lead to delayed puberty as is the case in girls with Turner syndrome, a genetic condition in which a female does not have the usual pair of two X chromosomes.

In these circumstances, endocrinologists typically prescribe treatment with sex steroids (gradually increasing doses of estrogen for girls and testosterone for boys).

Pubertal Timing Effects on Psychopathology

Early pubertal maturation has been linked to a broad range of psychopathological symptoms during adolescence for girls and boys.

For boys, earlier maturation has most consistently been associated with higher frequency of internalizing and externalizing symptoms during early and mid adolescenc.

Internalizing symptoms include depression, worry, fear, self-injury, and social withdrawal, whereas externalizing symptoms may include aggression, angry outbursts, law-breaking, or hyperactivity.

The effects of early pubertal maturation in girls seem to be much greater: early timing is associated with higher rates of depressive disorders, substance disorders, eating disorders, and disruptive behavior disorders (Graber, 2013).

Sexual behavior in those who mature earlier is also accelerated; these gifts tend to experience first sexual intercourse, first pregnancy, and first childbirth at earlier ages (Ellis, 2004); although there are only a few longitudinal studies, there is some evidence that issues facing early maturers in adolescence persist in young adulthood and beyond (Graber, Seeley, Brooks-Gunn, and Lewinsohn, 2004).

Late-maturing boys and girls differ from their early-maturing counterparts. In girls, those who mature later than their peers have more successful psychosocial, academic and other outcomes (Graber, Nichols, and Brooks-Gunn, 2010). Boys, however, tend to exhibit greater depressive symptoms and externalizing problems, as well as substance use and disruptive behaviors (Graber et al., 2004).

There are two well-known hypothesis regarding the association between pubertal timing and negative behavioral outcomes.

1. The early timing or developmental readiness hypothesis predicts that someone who reaches puberty earlier than peers will not be prepared for sudden emotional and increased drive in adolescence.
2. The off-time or maturational deviance hypothesis proposes that adolescents who develop either ealier or later relative to their peers experience psychological distress and manifest behavioral problems.

The maturational compression hypothesis was proposed to explain the relationship between tempo of puberty and psychosocial and behavioral relationship between tempo of puberty and psychosocial and behavioral problems (Mendle, Harden, Brooks-Gunn, and Graber, 2010).

This hypothesis predicts that early matures who advance through pubertal stages quickly develop psychological problems because they do not have the developmental time to become accustomed to the biological and social changes they experience.

Another possibility is that the surge in emotional reactivity associated with puberty outpaces the cognitive abilities of the adolescent. Brain regions implicated in behavioral regulation and self-control lag behind development of regions underlying emotion processing. As such, early maturers may struggle to regulate the strong emotions typically associated with pubertal onset because of normative delays in brain regions that play a strong role in emotion regulation.