Week 6 - anxiety & depression 2024- no video

Week 6: PaWeek 6 - anxiety & depression 2024- no videort 1 – Anxiety Disorders

• Instructor: Dr. Nicola Gregory (ngregory@bournemouth.ac.uk)

• Room: P115 L5 / L7 2024-2025

• Trigger Warning: Content includes discussions of anxiety and depression symptomology.

Lecture Information

• Subject: Biological Psychology

• Dates:

  • Lecture 1: November 13, 2024, 10:00 - 12:00

  • Lecture 2: November 15, 2024, 11:00 - 13:00

• Location: Bournemouth University

Key Terms

• Anxiety

• Stress

• Anxiety Disorders

• Generalized Anxiety Disorder (GAD)

• Social Anxiety Disorder (SAD)

• Stress Response

• HPA Axis (Hypothalamus, Pituitary gland, Adrenal gland)

• Corticotropin-releasing hormone (CRH)

• Adrenocorticotropic hormone (ACTH)

• Cortisol

• Sympathetic and Parasympathetic Nervous System

• Hippocampus

• Amygdala

• Insula

• Glucocorticoid receptors

• SSRIs (Selective Serotonin Reuptake Inhibitors)

• GABA (Gamma-Aminobutyric Acid)

• Orbitofrontal Cortex

• Resting-State Functional Connectivity

Learning Outcomes

• Understanding the types of anxiety and their diagnostic criteria

• In-depth study of Generalized Anxiety Disorder and Social Anxiety Disorder

• Exploration of the stress response

• Examination of key brain areas involved (e.g., amygdala, hippocampus, HPA axis)

• Cognitive neuroscience related to anxiety disorders

• Overview of pharmacotherapy for anxiety disorders

Anxiety Overview

• Definition: Chronic fear without a specific threat

• Symptoms of anxiety include tension, worry, and physical manifestations.

• Can be both innate and learned; may have adaptive qualities but can hinder functioning if excessive.

Classification of Anxiety Disorders (DSM V)

• Types:

  • Separation Anxiety Disorder

  • Selective Mutism

  • Specific Phobia

  • Social Anxiety Disorder

  • Panic Disorder

  • Agoraphobia

  • Generalized Anxiety Disorder

• Note: OCD and PTSD are categorized separately in DSM V.

Generalized Anxiety Disorder (GAD)

• Affects approximately 5% of the population.

• Characterized by excessive worry over 6 months, difficult to control.

• Accompanied by at least three of the following:

  • Restlessness / Edginess

  • Trouble concentrating

  • Increased fatigue

  • Irritability

  • Muscle tension

  • Sleep disturbances

• Symptoms cause significant distress and impaired function.

• Not due to substances, medical conditions, or other mental disorders.

Physiological Symptoms of GAD

• Symptoms may include:

  • Tachycardia

  • Palpitations

  • Hypertension

  • Sleep disturbances

  • Nausea

  • Dizziness

  • Fatigue

  • Rapid breathing

Aetiology of GAD

• Prevalence: 5% affected

• Comorbidity: 60-90% with other diagnoses

• Heritability: 15-20% genetic contribution

• Large environmental influence (stressful events, trauma, etc.).

Social Anxiety Disorder (SAD)

• Definition: Intense fear in social situations due to potential scrutiny.

• Key features include:

  • Fear of embarrassment or humiliation

  • Anxiety provoked in social situations, often leading to avoidance.

  • Persistent fear lasting over 6 months, causing distress and functional impairment.

  • Must not be attributable to substances or other mental conditions.

Aetiology of SAD

• Usually starts in teenage years, often triggered by a traumatic event.

• Heritability: 25-50%

• High prevalence of undiagnosed SAD, with many not seeking treatment.

Treatment Options for Anxiety Disorders

• Psychological: Usually CBT or psychotherapy; self-referral available.

• Pharmacological:

  • SSRIs are commonly prescribed.

  • Benzodiazepines used for severe cases.

Neural Mechanisms in Anxiety Disorders

• Hyperactivation of Stress Response: Common in all anxiety disorders.

• Activation occurs with a non-threatening stimulus.

Regulation of Stress Response

• Amygdala: Triggers stress response.

• Hippocampus: Inhibits stress response by measuring cortisol levels; chronic stress can damage glucocorticoid receptors, leading to HPA axis activation.

Cognitive Mechanisms in Anxiety

• Attentional Biases: Individuals with anxiety disorders disproportionately attend to threatening stimuli.

• In SAD, this bias is most prominent in social contexts.

Cognitive Neuroscience in Anxiety

• Research shows those with high social anxiety display increased focus on faces, reflecting attentional bias.

• Amygdala activity is more pronounced in anxiety patients, indicating less regulation by the orbitofrontal cortex (OFC).

Pharmacotherapy for Anxiety Disorders

• SSRIs: Increase serotonin availability and glucocorticoid receptors in the hippocampus, indirectly reducing HPA axis activation.

• Benzodiazepines: Act as fast-acting anxiolytics but should be used sparingly due to addiction potential.

Summary and Conclusions

• GAD and SAD are characterized by persistent fear triggered by inappropriate stress response activations.

• Hyperactivity of the amygdala is critical in anxiety disorders and pharmacotherapy is important for treatment.

Recommended Reading

• Essential: Chapter 22, Mental Illness, Bear et al.

• Etkin & Wagner, 2007 - Meta-Analysis: Emotional Processing in PTSD, Social Anxiety, and Specific Phobia.

• Hahn et al., 2011 - Resting-State Functional Connectivity in Social Anxiety Disorder.

Week 6: Part 2 – Depression

• Continue discussion on depression in biological psychology.

Key Terms

• Monoamines

• Serotonin

• Agonist

• SSRIs

• SNRIs

• Norepinephrine

• Brain Stimulation Techniques: tDCS, rTMS, ECT

• Neuroplasticity

• BDNF (Brain-Derived Neurotrophic Factor)

• Cognitive Function

Learning Outcomes for Depression Lecture

• Diagnostic criteria and prevalence of depression

• Understand monoamine theory and neuroplasticity theory

• Explore brain stimulation for treatment

• Investigate neural structure/function differences in depression.

Depression Diagnosis (DSM V)

• Criteria: 5 or more symptoms over two weeks; at least one must be:

  • Depressed mood or

  • Anhedonia (loss of pleasure)

• Other symptoms: weight changes, sleep issues, fatigue, worthlessness, concentration difficulties, suicidal thoughts.

Prevalence of Depression

• Approximately 10% of the population is affected.

• Genetic factors play a role, particularly in affective disorders.

Treatment Options for Depression

• Options vary based on severity:

  • Mild Depression: Low intensity psychotherapy (e.g., CBT)

  • Severe Depression: High intensity psychotherapy or antidepressants (e.g., SSRIs).

  • Brain stimulation for treatment-resistant depression.

Biological Models of Depression

• Monoamine Theory: Depression linked to underactivity of serotonin/norepinephrine systems.

• Neuroplasticity Theory: Depression associated with decreased neuroplasticity.

Antidepressants and Controversy

• Debate exists regarding the effectiveness of SSRIs for mild to moderate depression; more significant effects noticed in severe cases.

Neuroplasticity Theory and Antidepressants

• Antidepressants increase neuroplasticity, correlating with improved depressive symptoms; linked to BDNF.

Summary of Biological Models of Depression

• Monoamine theory: Focuses on monoamine underactivity.

• Neuroplasticity theory: Connects depression with diminished neuroplasticity.

Brain Stimulation Treatments

• Alternatives are considered if pharmacological methods fail.

• Techniques include tDCS, rTMS, and ECT for treatment-resistant cases.

tDCS and rTMS Overview

• Both techniques target the prefrontal cortex; shown to improve depressive symptoms over multiple sessions.

Structural and Functional Differences in Depression

• Studies have shown grey matter reductions in crucial brain areas, such as the prefrontal cortex and amygdala.

Cognitive Effects of Depression

• Mood-congruent memory: Depressive mood enhances the recall of negative memories.

Conclusion on Depression

• Summarize models and treatment options, considering the structural, functional, and cognitive impacts of depression.

References for Further Study

• Include suggested readings and additional resources for deeper insights into the topics discussed.