Etiology of depressive disorders in clinical psychology.pptx

Etiology of depression

1. Biological Factors of Depression

2. 1. G e n e t i cs Research has shown that depression can run in families, indicating a genetic component to the disorder. Genome-wide association studies (GWAS) have identified specific genetic variations associated with increased susceptibility to depression, including polymorphisms in the serotonin transporter gene (SLC6A4), commonly referred to as the SERT gene, which plays a crucial role in serotonin reuptake and neurotransmission. Individuals with a family history of depression are more likely to develop the condition themselves.

3. 2. Neurochemical Imbalance Depressive disorders have been associated with dysregulation of key neurotransmitters, particularly serotonin, norepinephrine, and dopamine. Serotonin plays a crucial role in mood regulation and emotional stability, with reduced serotonin levels linked to increased vulnerability to depression. Additionally, norepinephrine and dopamine are critical for motivation, reward processing, and arousal. Dysfunctions in these neurotransmitter systems, including deficiencies or imbalances, may contribute to the pathophysiology of depression by impairing emotional regulation, motivation, and cognitive function.

4. 3. Hormonal Fluctuations Depression is influenced by hormonal imbalances, particularly involving the HPA axis, thyroid hormones, and sex hormones : HPA Axis Dysfunction : Chronic stress leads to excessive cortisol secretion, contributing to neuronal damage and mood disturbances. Thyroid Hormones : Hypothyroidism is linked to depressive symptoms such as fatigue and cognitive impairment. Sex Hormones : Estrogen fluctuations affect serotonin and dopamine, increasing mood vulnerability (e.g., during menopause or postpartum). Progesterone withdrawal may trigger premenstrual dysphoric disorder (PMDD). Low testosterone is associated with depressive symptoms in both men and women.

5. 4.Brain Region Abnormalities in Depression Depression is linked to structural and functional changes in key brain regions: Prefrontal Cortex (PFC) : Reduced activity affects cognitive control over emotions. Amygdala : Hyperactivity increases emotional reactivity, especially to negative stimuli. Hippocampus : Shrinkage due to prolonged stress impairs memory and stress regulation. Anterior Cingulate Cortex (ACC) : Dysfunction disrupts emotional processing and self-regulation. Basal Ganglia & Striatum : Reduced dopamine signaling leads to anhedonia and low motivation.

6. Psychological Factors in Depression Depression is influenced by various psychological mechanisms, including cognitive, emotional, behavioral, and interpersonal factors. These processes interact with biological and environmental influences, increasing vulnerability to depressive disorders.

7. 1. Cognitive Factors Negative Cognitive Triad (Beck's Model) : Depressed individuals tend to have negative thoughts about themselves, the world, and the future , leading to hopelessness. Cognitive Distortions : Maladaptive thinking patterns, such as catastrophizing, overgeneralization, and black-and-white thinking, reinforce depressive symptoms. Rumination : Excessive focus on negative experiences and emotions prolongs distress and impairs problem-solving. Low Self-Efficacy : A belief in one's inability to influence life events can lead to passivity and further emotional distress. Maladaptive Core Beliefs : Deep-seated negative beliefs, such as “I am unworthy” or “I will always fail,” shape automatic thoughts and emotional responses.

8. 2. Learned Helplessness & Hopelessness Learned Helplessness (Seligman’s Theory) : Repeated exposure to uncontrollable stressors leads to passivity, withdrawal, and a belief that efforts are futile . Hopelessness Theory : Depressed individuals may attribute negative events to internal (it’s my fault), stable (it will always be this way), and global (it affects everything) causes , leading to despair and loss of motivation .

9. 3. Early Life Trauma & Attachment Issues Childhood Trauma : Neglect, abuse, or loss of a caregiver can lead to dysfunctional attachment styles , increasing emotional vulnerability. Attachment Styles : Insecure-Avoidant individuals may struggle with emotional disconnection and suppression of distress. Insecure-Anxious individuals may develop a fear of abandonment, leading to excessive worry and emotional instability. Disorganized Attachment is linked to extreme emotional dysregulation and dissociation. Adverse Childhood Experiences (ACEs) : Early exposure to stressors increases the likelihood of maladaptive coping mechanisms, low self-worth, and difficulties in emotional regulation .

10. 4. Emotional Dysregulation & Personality Traits Excessive Emotional Sensitivity : Individuals with high neuroticism may experience intense emotional fluctuations and react strongly to stress. Difficulty in Emotion Regulation : Struggles with identifying, expressing, and managing emotions contribute to persistent distress. Low Resilience & Coping Deficits : Ineffective coping strategies (e.g., avoidance, denial) can worsen depressive symptoms. Perfectionism & High Self-Demands : Unrealistically high expectations, fear of failure, and self-criticism contribute to chronic stress.

11. 5. Interpersonal & Social Factors Social Isolation & Lack of Support : Limited emotional connections and chronic loneliness increase vulnerability to depression. Interpersonal Conflict : Ongoing relationship difficulties , rejection, or loss of a loved one can trigger depressive episodes. Dependency on External Validation : Excessive need for approval or fear of disapproval can lead to self-esteem fluctuations and emotional instability. Workplace & Academic Stress : High demands, burnout , and chronic stress contribute to emotional exhaustion and depressive symptoms.

12. 6. Behavioral Factors & Lifestyle Influences Avoidance & Withdrawal : Reduced engagement in pleasurable or meaningful activities can reinforce low mood and lack of motivation. Sleep Disturbances : Chronic insomnia or poor sleep quality disrupts emotional regulation and cognitive function . Poor Self-Care : Neglecting basic needs, exercise, or nutrition can exacerbate depressive symptoms. Substance Use : Alcohol or drug use may serve as maladaptive coping mechanisms , further worsening mood disorders.

13. Social Factors in Depression Depression is influenced by various social factors, which can be categorized into three main areas: Interpersonal Relationships, Socioeconomic Factors, and Cultural & Environmental Influences .

14. 1. Interpersonal Relationships Social Isolation & Loneliness : Lack of close connections can lead to feelings of emptiness and despair. Relationship Conflicts : Chronic conflicts in family, friendships, or romantic relationships increase emotional distress. Breakups & Divorce : The loss of significant relationships can trigger depressive symptoms. Parental Influence & Attachment : Dysfunctional parenting and insecure attachment styles contribute to emotional vulnerability. Lack of Social Support : Weak support networks make it harder to cope with stress and adversity.

15. 2. Socioeconomic Factors Financial Stress & Poverty : Unemployment, debt, and economic instability increase chronic stress. Workplace Stress & Burnout : High job demands, toxic environments, and job insecurity contribute to emotional exhaustion. Academic & Career Pressure : Societal expectations around success can lead to feelings of inadequacy and depression. Housing & Living Conditions : Poor living environments and lack of stability can negatively affect mental health.

16. 3. Cultural & Environmental Influences Stigma & Mental Health Perception : Fear of judgment prevents many from seeking help. Discrimination & Social Oppression : Racism, sexism, and other forms of discrimination increase psychological distress. Social Media & Unrealistic Comparisons : Exposure to curated lifestyles can lead to low self-esteem. Migration & Cultural Adjustment : Relocating to a new country can cause social disconnection and loneliness. Traumatic Life Events : Death, abuse, or exposure to violence can have long-term effects on mental health.

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