Depressive Disorders

1
Depressive Disorders

• Chapter 17
• Daniel N. Klein, Autumn J. Kujawa, Sarah R.
  Black, and Allison T. Pennock

2
HISTORICAL CONTEXT

• Recognition of child and adolescent depressive
  disorders did not emerge until the late 1970s.
• Before the 1970s depression was thought to be
  rare in children and clinicians believed that
  depression was expressed in behavioral
  disturbances such as behavior problems, enuresis,
  and somatic concerns.
• During the late 1970s, investigators demonstrated
  that many children and adolescents met full adult
  criteria for major depressive disorder (MDD).

3
TERMINOLOGICAL AND CONCEPTUAL ISSUES

• Depression is a complex phenomenon and can
  encompass
• A mood state
• A clinical syndrome that can be caused by a
  variety of nonpsychiatric factors such as
  neuroendocrine disorders and psychoactive drug
  use
• A psychiatric disorder
• Depressive disorders are multifactorial
  conditionscaused by combinations of many
  etiological factors.
• Depressive disorders are probably etiologically
  heterogeneous, meaning that there are different
  subtypes of depression that are caused by
  different sets of etiological processes.
• Depressive disorders are characterized by both
  equifinality and multifinality.

4
DIAGNOSIS AND CLASSIFICATION

• DSM-IV (2000)
• MDD A period of persisting depressed or
  irritable mood or loss of interest or pleasure
  that lasts at least 2 weeks and is accompanied by
  a variety of other symptoms, including
• Low energy and fatigue
• Inappropriate feelings of guilt or worthlessness
• Difficulty thinking, concentrating or making
  decisions
• Sleep disturbance (insomnia or hypersomia)
• Appetite disturbance (eating too little or too
  much or significant weight loss or gain)
• Psychomotor disturbance (either retardation
  extreme slowing in movement and speech, or
  agitation extreme restlessness)
• Thoughts of death or suicidal thoughts or
  behavior.

5
DIAGNOSIS AND CLASSIFICATION

• Dysthymic disorder (DD) is a milder but more
  chronic condition, characterized by a period of
  depressed or irritable mood that is present for
  at least half the time for at least one year and
  is accompanied by several other depressive
  symptoms.
• Subtypes
• Unipolar-bipolar distinction, differential
  symptom presentation, and course.
• Unfortunately, subtyping has largely been ignored
  in child and adolescent depression.

6
DIAGNOSIS AND CLASSIFICATION

• Depression in Very Young Children
• Little research exists on depression in infants
  and preschool aged children
• Luby and colleagues (2003) reported that MDD can
  be identified in preschool-age children using
  modified DSM-IV criteria with a shorter duration
  requirement.
• Preschoolers meeting modified criteria for MDD
  had an 11-fold greater risk of exhibiting MDD 12
  to 24 months later compared to healthy children
  (Luby, Si, Belden, Tandon Spitznagel, 2009).

7
EPIDEMIOLOGY

• Prevalence
• Studies of community samples indicate that
  depression is rare in early childhood, increases
  somewhat in middle/late childhood, and rises
  sharply in adolescence.
• A meta-analysis of 26 studies estimated that the
  point prevalence of MDD was 2.8 in school-age
  children and 5.7 in adolescents (Costello,
  Erkani, Angold, 2006).
• By mid-late adolescence, the lifetime prevalence
  of depression approaches adult rates (Rudolph,
  2009).

8
EPIDEMIOLOGY

• Sex Differences
• Depressive symptoms and diagnoses in males and
  females are similar in childhood but between the
  ages of 12 and 15 rates among females increase
  markedly (Hyde, Mezulis, Abramson, 2008
  Nolen-Hoeksema Hilt, 2009).
• Comorbidity
• Depressed children and adolescents are
• 8.2 times more likely than nondepressed youths to
  meet criteria for an anxiety disorder
• 6.6 times more likely to meet criteria for
  conduct disorder
• 5.5 times more likely to meet criteria for
  attention-deficit/hyperactivity disorder (Angold,
  Costello, Erkanli,1999).

9
Course and Outcome

• Clinical samples tend to have a longer duration
  than community samples
• Mean duration of MDD episodes is approximately 7
  to 8 months.
• Episodes of DD last an average of 48 months.
• 40 to 70 of adolescents with MDD experience a
  recurrence in adulthood (Fombonne et al., 2001).
• Predictors of increased risk of recurrence
• Greater severity
• Psychotic symptoms
• Suicidality
• Prior history of recurrent MDD
• Subthreshold symptoms after recovery
• Depressotypic cognitions
• Recent stressful life events
• Adverse family environments
• Family history of MDD

10
RISK FACTORS

• Genetics
• Temperament
• Maladaptive parenting and abuse
• Biological factors
• Cognitive factors
• Peer relationships
• Life stress

11
Protective Factors

• Little research on protective factors in youth
  depression.
• Most research focuses on variables that appear to
  be the absence or opposite of established risk
  factors, such as high self-esteem and
  self-efficacy, an easy temperament, and family
  and peer support.

12
Conclusions and Future Directions

• Genetic factors play a role in youth depression,
  but the strength of their influence varies as a
  function of development, given that genetic
  effects increase with age.
• Genetic influences are likely to operate through
  intermediate phenotypes such as temperament and
  susceptibility to stress.
• Genetic influences are also mediated and/or
  moderated by a number of other risk factors.
• Two major sets of distal causes include genetic
  susceptibilities and early adversities.