Affective Disorders in Psychology: In-Depth Notes

Affective Disorders Overview

• Definitions: Mood disorders that primarily impact emotional states.
• Categories:
  • Depressive Disorders (e.g., Major Depressive Disorder, Seasonal Affective Disorder)
  • Bipolar Disorders (involving mania and depression)
  • Anxiety Disorders (includes panic disorders and PTSD)

Depression vs Clinical Depression

• Depression: Can arise from difficult life situations (e.g., sadness, grief).
• Clinical Depression (MDD): A persistent low mood and loss of interest lasting at least two weeks.

Major Depressive Disorder (MDD)

• Symptoms:
  • Persistently low mood and anhedonia (loss of interest in pleasurable activities).
  • Changes in sleep and appetite.
  • Cognitive issues such as memory and concentration.
• Hormonal Mechanisms:
  • Involves dysregulation of the Hypothalamic-Pituitary-Adrenal (HPA) axis:
  • Elevated Corticotropin-Releasing Hormone (CRH) and Adrenocorticotropic Hormone (ACTH).
  • may lead to hypercortisolemia (excess cortisol).
  • Effects on serotonin (5-HT) signaling & may involve sex hormones (low estrogen/testosterone levels increasing susceptibility).
• Diurnal Rhythm:
  • Cortisol is regulated by melatonin; abnormalities can imply chronic stress effects.

Seasonal Affective Disorder (SAD)

• Associated with disrupted circadian rhythms and stress; often characterized by depressive symptoms during certain seasons.

Manic and Depressive Symptoms

• Manic Symptoms: Elevated mood, heightened energy, impulsivity, and talkativeness.
• Depressive Symptoms: Sadness, fatigue, changes in sleep and appetite, and indecisiveness.

Cyclothymia

• A mood disorder characterized by milder mood swings between hypomania and mild depression.

Premenstrual Dysphoric Disorder (PMDD)

• Symptoms:
  • Severe depression, anxiety, irritability before menstruation.
  • Physical symptoms include bloating and headaches.
• Hormonal Mechanisms:
  • Normal hormone levels but abnormal sensitivity to fluctuations, especially in progesterone.
  • Allopregnanolone (ALLO):
  • Acts as a positive modulator of GABA-A receptors but can exacerbate mood swings in PMDD.

Postpartum Depression (PPD)

• Symptoms: Emotional highs and lows, anxiety, and trouble bonding with the infant. Affects about 15% of new mothers.
• Hormonal Changes:
  • Sharp drop in estradiol and progesterone post-birth can contribute to symptoms.
  • ALLO withdrawal and oxytocin dysregulation may also play a role.

Important Hormonal Relationships in Affective Disorders

• Major Affective Disorders :
  • MDD: HPA axis dysregulation, low sexual steroid levels.
  • PMDD: Hormonal sensitivity, GABAergic systems.
  • Bipolar Disorder & Anxiety Disorders: Dysregulated hormone systems affecting impulsivity and behavior.

Key Questions to Review

• What are the major categories of affective disorders?
• How does hormonal sensitivity differ in PMDD versus standard PMS?
• What is measured by the dexamethasone suppression test and its relation to mood disorders?
• How do childbirth-related hormonal changes impact postpartum depression and maternal behavior?