Mood Disorders: Major Depressive Disorder (MDD) and Persistent Depressive Disorder (PDD)

Overview of Depression

  • Common Symptoms:

    • Different underlying causes (etiologies), progression (courses), and treatments exist, although the symptoms may be similar across disorders.
    • Effective treatments for depression may require time to find the right combination.

  • Major Depressive Disorder (MDD):

    • A medical condition impacting feelings, thoughts, and behaviors.
    • Causes prolonged feelings of sadness and loss of interest in previously enjoyed activities.
    • Represented as the classic clinical diagnosis among depressive disorders.

  • Persistent Depressive Disorder (Dysthymia or PPD):

    • The second most common presentation of depressive symptoms.
    • Characterized as chronic depression where a person never experiences an excessively elevated mood or mania (referred to as unipolar depression).

Prevalence of Depression

  • According to the World Health Organization (WHO, 2017):

    • Depression is identified as the leading cause of disability around the globe.
    • Lifetime prevalence of MDD: 28.2%.
    • 12-month prevalence of MDD: 6.7% (according to National Institute of Mental Health (NIMH, 2017)).
    • Increased incidence observed across all age groups globally.
    • Gender Differences:
    • Women are 70% more likely than men to experience depression and tend to seek help more often.
    • Men more frequently utilize alcohol/substance use as a method of self-medication (according to Lliades, 2015).

  • Prevalence Rates for Other Depressive Disorders:

    • PPD with persistent major depressive episode (MDE): 15.2% lifetime prevalence.
    • PPD with pure dysthymia: 3.3% lifetime prevalence, a milder but chronic form of depression.
    • Other specified depressive disorders (OSDDs): 9.1% lifetime prevalence.

Comorbidity with Other Psychiatric Disorders

  • Depressive symptoms often accompany other psychiatric conditions, complicating their treatment.

    • Higher rates of suicide and increased severity of depression associated with comorbidity.
    • Common disorders that present with depression: anxiety disorders, PTSD, schizophrenia, substance use disorders, eating disorders, OCDs, schizoaffective disorder.
    • Individuals with chronic medical problems face a higher risk for developing depression (e.g., cancers, strokes, chronic pain, heart disease according to Mayo Clinic Staff, 2017).
    • Depression prevalence among all hospitalized patients ranges from 5% to 60%, with a median of 33%. Associated with poor functional outcomes and increased hospital readmission rates (according to IsHak et al., 2017).

  • Medication Inducing Depression:

    • Heart and high blood pressure medications, steroids, birth control pills, sleeping pills, antibiotics/antivirals can induce depression in susceptible individuals (according to Harvard Health Publishing, 2017).

Depression in Different Age Groups

Children and Adolescents

  • Increasing incidence of severe depression in youth, from 5.9% in 2012 to 8.2% in 2015 (according to Mental Health America, 2018).
  • Children as young as 3 can be diagnosed with MDD; the incidence for children under 12 is 2.5%.
  • Symptoms in children: irritability, physical complaints, decline in academic performance, and social withdrawal.
  • After puberty, girls are at double the risk of developing depression compared to boys.
  • Substance Use: Children with depressive symptoms may start using drugs and alcohol earlier (according to WebMD Medical Reference, 2016).
  • Incidence in Adolescents (ages 12-17):
    • At least one MDE in a year: 11.93% (according to Nguyen et al., 2017).
    • Adolescents may mask their depression via sulking, negativity, behavioral issues at school, feelings of being misunderstood, and withdrawal.
  • Relapse rates post-depression recovery in children: 30% to 70%; for adolescents: 20% to 50% (according to Bonin, 2016).

Older Adults

  • Clinical depression prevalence: 7% among older adults, with significant disability markers (according to WHO, 2017).
    • Incidence in different demographics:
    • Community-dwelling older adults:
    • Home health care patients: 13.5%.
    • Hospitalized older patients: 11.5% (according to CDC, 2017).
  • Common Symptoms:
    • Identifiable symptoms in older adults: Sadness complaints are less prominent; excessive concern over physical health.
    • Older adults may assume their depressive symptoms are part of aging, leading to under-recognition and undiagnosis.
    • Higher suicide rates noted in older populations (according to Kok & Reynolds, 2017).
  • Key Assessment Tools: Geriatric Depression Scale for better mental health care integration in elderly communities.

Theory and Causation of Depression

  • Complex Nature: Genetic, biochemical changes, environmental, and psychological factors contribute to the development of depression.

Genetic Factors

  • Twin Studies: Monozygotic twins show a 50% chance of both having unipolar depression if one is affected, whereas dizygotic twins have a 20% chance.
  • Family history of depressive disorders notably escalates risk (people with a first-degree relative with depression are 2-4 times more likely).

Risk Factors for Depression (Box 15.1)

  • History of prior depressive episodes.
  • Family history of depression or suicide.
  • Membership in the LGBTQ community.
  • Gender: Higher incidence in females.
  • Age: Younger age increases risk.
  • Chronic illnesses can precipitate the onset of depression.
  • Absence of social support and negative life events increase vulnerability.

Biochemical Factors

  • Neurotransmitters implicated: Serotonin, norepinephrine, dopamine, glutamate, GABA, acetylcholine (according to Harvard Health Publishing, 2017).
  • Disruptions in receptor sites for these neurotransmitters might lead to depressive symptoms, impacting medication efficacy.

The Stress-Diathesis Model of Depression

  • Framework analyzing depression as the result of environmental stressors affecting a biologically vulnerable individual.
  • Relationship with neurophysiological changes: early trauma prompting long-term stress alterations, impacting mood regulation (CNS influence).

Cognitive Theory

  • Cognitive-Behavioral Therapy: Aaron T. Beck's view on early-life experiences creating a disposition toward negative, illogical thoughts.
  • The cognitive triad highlights negative thinking patterns contributing to depression, emphasizing:
    • What you think = What you feel/do.
  • Automatic negative thoughts can perpetuate depressive feelings (e.g., personalization of social interactions).

Clinical Picture of Major Depressive Disorder and Persistent Depressive Disorder

Major Depressive Disorder (MDD)

  • Represents substantial emotional pain and dysfunction affecting daily living.
  • Symptoms can resolve naturally in a subset of individuals (20% in 3 months and up to 80% in 1 year) but increases the risk of future episodes.
  • Symptoms recognized via the mnemonic SIG E CAPS:
    • Sleep disturbances, Sad mood, Interest loss, Guilt, Energy reduction, Concentration issues, Appetite changes, Psychomotor changes, Suicidal thoughts.
  • Diagnosis dimensions: mild, moderate, severe episodes, and include DSM-5 specifiers for additional symptoms.

Persistent Depressive Disorder (PDD)

  • Chronic disorder with symptoms lasting at least 2 years.
  • Presents with less severe symptoms compared to MDD but often entails significant social distress.
  • Symptoms can include continuous daytime fatigue.

Assessment of Clinical Depression

  • Depression assessment should focus on recognizing diverse symptoms across populations, including older adults and adolescents.
  • Underdiagnosis is common in minority groups due to socioeconomic factors.
  • Regular screening for depression is highly recommended via standardized tools, including the Beck Depression Inventory, Hamilton Depression Scale, Geriatric Depression Scale, and PHQ-9.

Suicide Risk and Homicide Potential Assessments

  • High priority in evaluating suicidal ideation, with shocking statistics highlighting serious risk:
    • 78% of suicides occur among males; suicide is the 10th leading cause of death across all age groups.
  • Assessment for current and past thoughts or attempts of suicide is critical.

Standardized Tools for Depression Detection

  • Edinburgh Postnatal Depression Scale (EPDS) specifically targets pregnant/postpartum women for depression screening.
  • Evidence indicates that screening reduces prevalence and enhances treatment responses.

Conclusion

  • Recognizing symptoms, understanding risk factors, treatment implications, and responsible screening practices are essential in the nursing process related to mood disorders, specifically depression, to ensure appropriate patient care and intervention.