Lecture on Major Depressive Disorder

Overview

• Major Depressive Disorder (MDD) is characterized by prolonged feelings of helplessness and discouragement about the future.
• Symptoms include:
  • Low self-esteem, worthlessness
  • Lack of energy
  • Social isolation, trouble focusing, and making decisions
  • Pervasive low mood affecting all life aspects

Physical Symptoms

• Lethargy or fatigue
• Fluctuations in weight (significant gain or loss)
• Sleep disturbances (insomnia or hypersomnia)
• In Western cultures, focus tends to be on mood/emotional states, while some Eastern cultures emphasize bodily symptoms.
• Depression is the leading cause for seeking mental health services, often referred to as the "common cold" of psychological disorders.

Prevalence

• 13% of men and 22% of women worldwide may experience depression once in their lives.
• Up to 31% of college students may experience depression.

Misconceptions

• Depression is not just feeling sad occasionally; it's a serious disorder.
• Can be triggered by life events or exist without apparent cause.
• Often coexists with other disorders like anxiety.

Factors Contributing to Depression

Biological Factors

• Genetic component identified by family and twin studies.
• Decreased activation in the prefrontal cortex affecting decision making and action generation.
• Lower activity in brain's reward circuitry leading to loss of enjoyment.
• Fewer receptors for neurotransmitters like serotonin.
• Research on serotonin transporter gene (5-HTTLPR):
  • Associated with depression in stressful environments.
  • Can lower depression risk in positive environments.

Psychological Factors

• Learned Helplessness: Repeated exposure to uncontrollable adverse situations can lead to feeling powerless.
• Cognitive Theories: Negative thought patterns may trigger depression.
  • Individuals may emphasize negative experiences and thoughts.
• Attributional Style: Depressed individuals often attribute negative events to internal, stable, global causes.
  • Leads to a pessimistic attributional style.

Sociocultural and Environmental Factors

• Depression can spread among close individuals (partners/friends) through co-rumination.
• Low socioeconomic status, poverty, unemployment are risk factors.
• Social isolation, child abuse, and prejudice can contribute to depression.
  • Internalized prejudice, such as homophobia, can lead to depression.

Biopsychosocial Model

• Integrates biological, psychological, and sociocultural factors.
• Recognizes that genetic predispositions may manifest under certain environmental conditions or thought patterns.