Adolescence 8th edition

1. Adolescence8th edition Insert Photo from DAL Chapter One: Biological Transitions By Laurence Steinberg, Ph.D.

2. Chapter 1 Overview • What is puberty? • What is the endocrine system? • What triggers puberty? • What are the physical changes of puberty? • Variations in the timing and tempo of puberty • What is the psychosocial impact of puberty? • Early vs. Late maturation • Eating disorders • Physical health in adolescence

3. Puberty: An Introduction • From Latin word pubertas (adult) • Period of lifespan in which an individual becomes capable of sexual reproduction • Hormones regulated by the endocrine system lead to physical changes • No new hormones are produced and no new bodily systems develop at puberty

4. The Endocrine System • Produces, circulates, and regulates hormone levels in the body • Hormones • Substances secreted by endocrine glands • Glands • Organs that stimulate particular parts of the body to respond in specific ways • Feedback loop (HPG axis) • Set point (Example: thermostat)

5. The Endocrine System: HPG Feedback Loop • HPG Axis: • Hypothalamus • Pituitary gland (master gland) • Gonads (testes and ovaries) • Gonads release sex hormones into bloodstream • Androgens and estrogens

6. What Triggers Puberty? • Although no new hormones in adolescence, something signals the HPG axis to kick on • Presence of mature sexual partners • Nutritional resources • Leptin may be the most important signal • Protein produced by fat cells • Must accumulate enough body fat (~11%) • Rising levels of leptin signal hypothalamus to stop inhibiting puberty (at least in females) • Adrenarche • Maturation of adrenal glands leads to physical (somatic) changes

7. What Role Do Hormones Play? • Organizing Role • Prenatal hormones “program” the brain to be masculine or feminine (like setting an alarm clock) • Patterns of behavior as a result of this organization may not appear until adolescence (Ex: sex differences in aggression) • Activating Role • Increase in certain hormones at puberty activates physical changes (Ex: secondary sex characteristics)

8. Puberty is Affected by Context • Timing of physical changes in adolescence varies by • Regions of the world • Socioeconomic class • Ethnic group • Historical era • Example: Menarche (first menstruation) • U.S. average 12 to 13 years • Lumi (New Guinea) average > 18 years Insert picture from DAL

9. What Are The 5 MajorPhysical Changes of Puberty? • Adolescent growth spurt • Development of primary sex characteristics (gonads) • Development of secondary sex characteristics (breasts, pubic hair) • Changes in body composition • Changes in circulation and respiration

10. Physical Changes of Puberty:Adolescent Growth Spurt • Adolescent growth spurt • Rapid acceleration in growth (height and weight) • Simultaneous release of growth hormones, thyroid hormones, and androgens • Peak Height Velocity (Time that adolescent is growing most quickly) • Average female growth spurt is 2 years earlier than the average male growth spurt

11. Physical Changes of Puberty:Adolescent Growth Spurt

12. What Are The Physical Changes of Puberty? • Changes in body composition • Relative proportions of body fat/muscle change • Different for boys (more muscle) and girls (more fat) • Skeletal changes(Bones become harder, denser, more brittle) • Closing of ends of long bones (epiphysis) • Asymmetry of growth • Circulatory and respiratory changes • Size and capacity of heart and lungs • Exercise tolerance

13. Sexual Maturation: Overview • Development of secondary sex characteristics • Measured in boys and girls by Tanner Stages • Changes include • growth of pubic hair • changes in appearance of sex organs • breast development

14. Sexual Maturation: Boys • Spermarche typically occurs 1 year after accelerated penis growth • Boys capable of fathering a child before they look like adults; opposite true for girls

15. Sexual Maturation: Girls • Sequence less regular than in boys • Menarche typically occurs after other secondary sex characteristics; regular ovulation follows 2 years later • Thus, girls appear physically mature before they are actually capable of reproduction

16. Variations in the Timing and Tempo of Puberty • No specific average age at onset or duration of puberty • No relation between the age at which puberty begins and the rate of pubertal development • Timing (early or late) and adult stature • Small effect: late maturers slightly taller as adults, early maturing girls slightly heavier as adults • Childhood height and weight • Stronger correlation with adult height and weight

17. Variations in the Timing and Tempo of Puberty

18. Individual Differences in Pubertal Maturation • Pubertal maturation • Interaction between genes and environment • Differences in timing/rate among individuals in the same general environment result chiefly from genetic factors • Two key environmental influences • Nutrition • Health • Exposure to pheromones Insert photo from DAL

19. Group Differences in Pubertal Maturation • Typically studied by comparing average age of menarche • Across countries • Age at menarche lower when not malnourished (Ex: Africa and United States) • Among SES groups within a country • Affluent girls reach menarche before disadvantaged girls • Within same populations but different eras

20. Group Differences in Pubertal Maturation • Secular trend (group trend within same region) • Leveling off in industrialized nations • Better sanitation, control of infectious diseases • U.S. average age of menarche has not changed in 30 years • Onset of puberty has continued to occur earlier among African-American girls in the United States

21. Group Differences in Pubertal Maturation • Secular trend (group trend within same region) • Leveling off in industrialized nations • Better sanitation, control of infectious diseases • U.S. average age of menarche has not changed in 30 years • Onset of puberty has continued to occur earlier among African-American girls in the United States

22. The biological changes of puberty can affect the adolescent’s behavior in at least three ways

23. How Do Researchers Study The Psychosocial Consequences of Puberty? • Groups compared at different stages of puberty • Cross-sectional study design • Longitudinal study design • Same adolescents tracked over time • Comparison of early vs. late maturers • When interested in the effects of pubertal timing on psychosocial outcomes

24. The Immediate Impact of Puberty • Self-esteem varies by gender and ethnicity • Adolescent moodiness • More fluctuations throughout the day than adults • Not solely due to hormones • Changes in patterns of sleep • Delayed phase preference and later melatonin secretion • Environmental influences and school start times • Family relationships • Peer relationships

25. The Immediate Impact of Puberty

26. The Psychosocial Impact of Specific Pubertal Events • Most adolescents react positively to pubertal changes • especially secondary sex characteristics • Reactions to menarche are varied • but less negative than in the past • Less known about boys’ reactions to first ejaculations Insert photo from DAL

27. Psychosocial Impact of Early or Late Maturation: Boys • Perception of being an early or late maturer is more important in affecting one’s feelings than the reality • Pros of early maturation • Popularity, better self-esteem • More responsible, cooperative, sociable later in adulthood • Cons of early maturation • More drug and alcohol use, precocious sexual activity, greater impact of victimization • Less creative, more humorless in later adulthood

28. Psychosocial Impact of Early or Late Maturation: Girls • Compared to early maturing boys, early maturing girls have more difficulties • Maturational deviance hypothesis • Developmental readiness hypothesis • Cultural and contextual factors (valuing thinner body types) • Pros of early maturation • Popularity with boys • Cons of early maturation • Heavier and shorter stature later in life • Precocious sexual activity, lowered self-image, higher rates of depression, eating disorders, anxiety

29. Psychosocial Impact of Early or Late Maturation: Girls

30. Eating Disorders • Body Dissatisfaction • Higher among early maturing girls • Puberty brings rapid increase in body fat for girls • Obesity • The most common pattern of disordered eating among adolescents • Basal Metabolism Rate • Disordered eating • Patterns of eating, attitudes, and behaviors that are unhealthy.

31. Eating Disorders • Deviation from the “ideal” physique can lead to loss of self-esteem and other problems in the adolescent’s self-image • Studies of magazines, 1970 to 1990 • Ideal body shape became slimmer • Ideal body shape became less curvaceous

32. Marilyn Monroe Height: 5 feet 5 1/2 inchesWeight: Varied, approx. 120 lbs. Measurements: 37-23-36 Dress size: 12Pant Size: 8 Kate Moss Height: 5 feet 6 inchesWeight: 105 lbs. Measurements: 33-23-35 Dress size: 4Pant Size: 2

33. Eating Disorders • Characterized by: • severe disturbance in eating behavior • Intense fear of becoming overweight which leads to the pursuit of thinness • This fear is relentless and may become deadly • Types of Adult Eating Disorders: • Anorexia Nervosa • Bulimia Nervosa • Obesity also has disordered eating patterns, but at this moment it is not considered an eating disorder

34. Eating Disorders:Bulimia & Anorexia Nervosa • Adolescents with these eating disorders have an extremely distorted body image • The definitions below are provided by the book, but I do not agree…I am providing them as a point of reference: • Bulimia • Eating binges; force themselves to vomit to avoid weight gain • 3% of adolescents are genuine bulimics • Anorexia • Starve themselves to keep weight down • Fewer than one-half of 1% of adolescents • Bulimia and Anorexia 10 times more common among females

35. Anorexia Nervosa • Name originated from the idea that there was a “lack of appetite induced by nervousness” • Characterized by: • Intense fear of weight gain • Refusal to maintain healthy body weight • Women: • At this time, this diagnosis requires that a woman does not have their period. However, there is much controversy associated with this. • Men: • Decrease in sexual appetite and testosterone • Patients may deny having a problem • May be quietly proud of their achieved thinness • May be life persistent • Mortality rate is 12 times higher than regular population • Death is usually due to physiological consequences (i.e. brain atrophy, etc. ) or suicide

36. Types of Anorexia Nervosa • Restricting Type: • Limit food and caloric intake • Avoid eating in front of others • When eating with others they may eat slowly or dispose of food • Admired by others with eating disorders • Binge Eating/Purging Type: • Either binge, purge, or binge and purge • Binge: out of control eating of amounts of food that are far greater than what a normal person would eat • May be followed by purging • Purging: Self induced vomiting, misuse of laxatives, diuretics, enemas, etc • This doesn’t stop caloric intake • Approximately 30% to 50% go from Restricting to Binge Eating Purging

37. Bulimia Nervosa • Characterized by: • Binge eating and efforts to prevent weight gain by using unhealthy behaviors such as self induced vomiting, laxatives, exercise, etc. • Person is not severely underweight. Typically, they are normal weight. • Usually begins by restricting eating to lose weight. Then the person eats “forbidden food”. • Binge: may be equal to about 4,800 calories • May feel disgusted, but continue due to fear of weight gain • Feel shame and guilt

38. Types of Bulimia Nervosa • Purging: • Vomiting, laxatives, diuretics • Most common (make up 80% of those diagnosed with Bulimia Nervosa). • Non Purging: • Exercise

39. Risk Factors for Eating Disorders • Eating Disorders are believed to be caused by an interaction of biological, socio cultural, family, and individual variables.

40. Treatment for Anorexia Nervosa • Medications: • No strong evidence that medication is helpful • Antidepressants and antipsychotic medications are sometimes used to help with disturbed thinking • Family Therapy: • Treatment of choice for adolescents • Therapist works with parents to get child to begin to eat again • After weight gain, other family problems are discussed • Randomized controlled trials show that patients who receive family therapy do better than the control group and five years after treatment 75 to 90 percent are fully recovered • Cognitive Behavioral Therapy: • Changing behavior and maladaptive ways of thinking • Treatment will usually last for one to two years • Modifying distorted beliefs about food, weight, and the self which have led to the disorder • Recovery rate of about 17%

41. Treatment for Bulimia Nervosa • Medication: • Antidepressants are commonly used • co-morbidity with mood disorders may be a factor • Seem to decrease binges and improve patient’s mood and preoccupation with shape and weight • Cognitive Behavioral Therapy: • Treatment of choice • Shown to be superior to medication and interpersonal therapy • Combining CBT with medication only slightly increases the results • Used to normalize eating patterns • Meal planning, nutritional education, and ending binging and purging cycles by teaching the person to eat small amounts of food throughout the day • Changing cognitions and behaviors that initiate binge cycle through challenging dysfunctional thought patterns such as: • All or nothing thinking • Idea of good food versus bad food

42. Treatment Outcomes • Eating Disorders are difficult to treat & have high relapse rates • Anorexia Nervosa: • Study conducted by Lowe two years after treatment: • 16% no longer alive (mostly due to complications of starvation or suicide) • 10% had not recovered • 21% partially recovered • 51% completely recovered • Bulimia Nervosa: • Study conducted 11 years after treatment: • 0.5% mortality rate • 70% recovered • 30% still had it • It is important to note that the client may recover, but may still have food issues.

43. Physical Health and Health Care in Adolescence • Adolescent health care needs differ from those of children and adults • Health compromising and health enhancing behaviors • School-based health centers • 10% are family planning visits • Most visits involve injuries, acute illnesses and mental health Insert photo from DAL

44. Physical Health and Health Care in Adolescence • PARADOX: Adolescence is a healthy period of the lifespan • But nearly 1 in 15 adolescents experiences at least one disabling chronic illness: • mental disorders (depression) • respiratory illnesses (asthma) • muscular and skeletal disorders (arthritis)   • Threats to health have psychosocial causes (not natural causes)

45. Adolescent Mortality • Today • 45% of teen deaths due to car accidents and other unintentional injuries • 30% of teen deaths due to homicide and suicide • 50 Years Ago • Most deaths from illness and disease