AP Psychology Lesson: Bipolar, Depressive, Anxiety, and OCD Disorders

Unit: Mental and Physical Health | Lesson: 4 of 8 | Topic: Bipolar, Depressive, Anxiety, and OCD Disorders
AP Exam Weighting: 15%–25%
Instructions: Complete this lesson during class by filling in the blanks and answering questions. All information needed is provided or will be researched in class. This lesson prepares you for the AP Psychology exam by exploring mood and anxiety-related disorders. Use the provided spaces to write your answers clearly, focusing on applying concepts critically.

Warm-Up

Purpose: Get you thinking about how mood and anxiety disorders affect behavior.
Questions:

  1. How might persistent sadness change someone’s daily life?
  2. Why might excessive worry make it hard to focus?
    Your Answers: Write a short response (1–2 sentences) for each question.

Key Concepts

Instructions: Read the information below and answer the questions to learn core AP concepts. For definitions, write them in your own words based on the content or look up a different definition if directed by your teacher (e.g., via apa.org or Google Scholar).
Content: Bipolar disorders involve mood swings between mania (elevated mood) and depression. Depressive disorders include persistent sadness and loss of interest (e.g., major depressive disorder). Anxiety disorders feature excessive worry (e.g., generalized anxiety disorder). Obsessive-compulsive disorder (OCD) involves intrusive thoughts (obsessions) and repetitive behaviors (compulsions). Example: A person with OCD repeatedly checks locks due to fear of intruders. These disorders disrupt behaviors like work or relationships. Biological factors (e.g., serotonin imbalances) and environmental stressors contribute. Diagnosis uses DSM-5 criteria.

  1. Define bipolar disorders in your own words: _______________________________
  2. Define anxiety disorders in your own words: _______________________________
  3. Define obsessive-compulsive disorder in your own words: _______________________________
  4. Explain how a depressive disorder influences a behavior, using a specific example:
  1. Explain how OCD influences a behavior, using a different example:
  1. How do biological factors contribute to bipolar disorders?
  1. Why might environmental stressors worsen anxiety disorders?
  1. How does the DSM-5 ensure accurate diagnosis of these disorders?

Biological Causes of Anxiety, Depression (MDD), and Schizophrenia

焦虑、抑郁（MDD）、精神分裂症的生物学成因

一、Anxiety Disorders 焦虑障碍

Biological Causes / 生物学成因

  1. Genetic predisposition / 遗传易感性
    • English: Family and twin studies show higher concordance rates among blood relatives; anxiety has moderate heritability.
    • 中文：家系与双生子研究显示亲属同病率更高，焦虑具有中等程度的遗传度。
  2. Neurotransmitter irregularities / 神经递质异常
    • English: Abnormalities in GABA (low inhibitory activity), serotonin, and norepinephrine lead to difficulty regulating fear and arousal.
    • 中文：**γ- 氨基丁酸（GABA）** 抑制功能不足、5 - 羟色胺（血清素）与去甲肾上腺素失衡，导致恐惧与唤醒难以调节。
  3. Brain structure and function / 脑结构与功能异常
    • English: Hyperactivity of the amygdala (fear center); reduced prefrontal cortex regulation over emotional responses.
    • 中文：** 杏仁核（恐惧中枢）** 活动过度；前额叶皮层对情绪反应的调控能力下降。
  4. Autonomic nervous system hypersensitivity / 自主神经系统高敏感性
    • English: Heightened sympathetic nervous system reactivity (fight-flight-freeze) to mild threats.
    • 中文：交感神经系统对轻微威胁表现出过度的 “战斗 - 逃跑 - 冻结” 反应。

二、Major Depressive Disorder (MDD) 重性抑郁障碍

Biological Causes / 生物学成因

  1. Genetic factors / 遗传因素
    • English: Strong heritability; higher risk for identical twins, first-degree relatives, and individuals with family history of mood disorders.
    • 中文：遗传度较高；同卵双生子、一级亲属及有情绪障碍家族史者患病风险显著上升。
  2. Monoamine hypothesis (classic) / 单胺类假说（经典理论）
    • English: Deficiencies in serotonin, norepinephrine, and dopamine are associated with low mood, anhedonia, and fatigue.
    • 中文：5 - 羟色胺、去甲肾上腺素、多巴胺水平不足，与情绪低落、快感缺失、精力衰退相关。
  3. Neuroplasticity and neurotrophic factors / 神经可塑性与神经营养因子
    • English: Low levels of BDNF (Brain-Derived Neurotrophic Factor) reduce neuron growth, repair, and connectivity in mood-related circuits.
    • 中文：** 脑源性神经营养因子（BDNF）** 水平降低，导致情绪相关脑区神经元生长、修复与连接受损。
  4. Brain structure and activity / 脑结构与活动
    • English: Reduced activity in the prefrontal cortex (decision-making, mood control); smaller hippocampus (linked to stress and memory); hyperactive amygdala.
    • 中文：前额叶皮层（决策、情绪调控）活动降低；海马体体积缩小（与应激、记忆相关）；杏仁核活动亢进。
  5. HPA axis dysregulation / 下丘脑 - 垂体 - 肾上腺轴（HPA 轴）功能紊乱
    • English: Chronic elevated cortisol (stress hormone) impairs neurons and increases vulnerability to depression.
    • 中文：长期皮质醇（应激激素）偏高损伤神经元，提升抑郁易感性。

三、Schizophrenia 精神分裂症

Biological Causes / 生物学成因

  1. Dopamine hypothesis / 多巴胺假说（核心生物学理论）
    • English: Excessive dopamine activity in the mesolimbic pathway is strongly linked to positive symptoms (delusions, hallucinations, disorganized thinking).
    • 中文：中脑边缘通路多巴胺活动过度，与阳性症状（妄想、幻觉、思维紊乱）高度相关。
  2. Genetic vulnerability / 遗传易感性（素质 - 应激模型核心）
    • English: Very high heritability; concordance rate ~48% in identical twins, ~17% in fraternal twins. Multiple genes contribute to risk.
    • 中文：遗传度极高；同卵双生子同病率约 48%，异卵双生子约 17%，由多基因共同增加患病风险。
  3. Brain structure abnormalities / 脑结构异常
    • English: Enlarged cerebral ventricles; reduced volume and activity in the prefrontal cortex and temporal lobe; hippocampal abnormalities.
    • 中文：脑室扩大；前额叶、颞叶体积与活动下降；海马体结构异常。
  4. Neurodevelopmental factors / 神经发育因素
    • English: Prenatal viral infection, maternal malnutrition, birth complications, and early brain damage increase risk.
    • 中文：孕期病毒感染、母体营养不良、分娩并发症、早期脑损伤等均会提升发病风险。
  5. Other neurotransmitter involvement / 其他递质参与
    • English: Abnormalities in glutamate (NMDA receptor hypofunction) and serotonin contribute to both positive and negative symptoms.
    • 中文：谷氨酸系统（NMDA 受体功能低下）、5 - 羟色胺异常，共同参与阳性与阴性症状的形成。

一页浓缩版（PPT 专用・双语极简）

Anxiety / 焦虑

  • Genetics / 遗传
  • Low GABA, serotonin imbalance / GABA 不足、血清素失衡
  • Hyperactive amygdala / 杏仁核过度活跃
  • SNS hypersensitivity / 交感神经过敏

MDD / 重性抑郁障碍

  • Genetics / 遗传
  • Low serotonin, norepinephrine / 血清素、去甲肾上腺素不足
  • Low BDNF, small hippocampus / BDNF 降低、海马体缩小
  • HPA axis overactivity / HPA 轴亢进

Schizophrenia / 精神分裂症

  • Excess dopamine (positive symptoms) / 多巴胺过多（阳性症状）
  • Strong genetics / 强遗传基础
  • Enlarged ventricles, low prefrontal activity / 脑室扩大、前额叶活动低
  • Prenatal/neurodevelopmental insults / 孕期与神经发育损伤
  • Glutamate dysfunction / 谷氨酸系统功能异常

Guided Activity

Instructions: Work in pairs to complete the two tasks below. Write your answers and be prepared to share one key point from each task with the class.
Task 1: Scenario Analysis: Scenario: A student with depression skips classes due to low energy. Analyze how a depressive disorder and DSM-5 criteria contribute to their diagnosis. For example, consider how symptoms or diagnostic standards guide identification.
Your Response for Task 1: Explain the role of each concept in the diagnosis.

Class Share for Task 1: Note one point you’ll share.

Task 2: Case Application: Imagine a person with OCD washes their hands repeatedly due to fear of germs. Apply the concepts of OCD and biological factors to explain their behavior. For example, evaluate how compulsions or brain chemistry affect their actions.
Your Response for Task 2: Apply the concepts to explain the behavior.

Class Share for Task 2: Note one point you’ll share.

Class Assignment: Refer to the assignment file for this lesson

Instructions: Complete the tasks below to deepen your understanding of mood and anxiety disorders.
Study Summary 1: A 2019 study found that serotonin imbalances were linked to depressive disorders in young adults.
Question 1: How does this study demonstrate the role of biological factors in depression, and what might enhance treatment outcomes?

Study Summary 2: A 2020 study showed that cognitive therapy reduced symptoms of anxiety disorders in adolescents.
Question 2: Evaluate how this study illustrates the impact of environmental interventions on anxiety, and suggest one limitation of its findings.

AP Exam Connection: This practices analyzing and evaluating research, a key skill for FRQs.

AP Exam Practice

Instructions: Answer the question below. We’ll review answers as a class to learn exam strategies.
Free-Response Question (FRQ):
Explain how bipolar disorders, anxiety disorders, and OCD interact to influence a specific behavior (e.g., social withdrawal or repetitive actions). Provide one example for each disorder (bipolar, anxiety, OCD) and analyze how they interact to shape the behavior.

Closure

Instructions: Write a brief summary (2–3 sentences) of two key ideas you learned today about how mood and anxiety disorders affect behavior.

Extended Practice

Instructions: Complete the tasks below based on today’s lesson to reinforce AP skills.

  1. Review your answers from this lesson.
  2. Write a detailed paragraph (5–7 sentences) applying today’s topic to a real-life scenario (e.g., how a disorder affects someone’s school or social life). Include references to bipolar disorders, anxiety disorders, and OCD, and explain their interaction.
  1. Find a short article or study on mood or anxiety disorders (e.g., via apa.org) and write 2–3 sentences summarizing its relevance to today’s lesson. Cite the source (e.g., website or article title).
Last modified: Thursday, 5 February 2026, 3:59 AM