Psychological Disorders II: Anxiety, OCD, Mood Disorders, and Schizophrenia

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Anxiety, Obsessive-Compulsive, & Depressive Disorders

Anxiety Disorders

Anxiety disorders are characterized by excessive, irrational, and maladaptive fear or nervousness. These disorders are common and often comorbid with other psychological conditions. Symptoms can include physiological responses such as fight-or-flight, freeze, or faint reactions. Anxiety disorders are not a sign of mental weakness, and seeking help is important for effective management.

Generalized Anxiety Disorder (GAD): Marked by frequently elevated levels of anxiety, often in response to everyday life challenges. Individuals experience a general sense of unease that is difficult to control, often linked to heightened amygdala sensitivity to stressors.
Panic Disorder: Characterized by sudden, intense episodes of fear known as panic attacks. Individuals may develop agoraphobia, a fear of having a panic attack in public places.
Specific Phobia: Involves intense fear of a particular object, activity, or organism. Genetic factors may contribute, as shown by selective breeding studies of fear responses.
Social Phobia (Social Anxiety Disorder): Involves a strong fear of being judged or embarrassed in social situations. Cultural phenomena such as Hikikomori (social withdrawal) are related.

Examples of social anxiety behaviors Selective breeding and freezing response in anxiety

Type of Phobia	Examples
Natural environment type	Heights, thunderstorms, large bodies of water
Situational type	Closed spaces (e.g., elevators), crowds
Animal type	Spiders, snakes, mice
Blood/injection/injury type	Seeing blood or broken bones, seeing needles
Other type	Fear of vomiting or choking

Table of phobia types and examples

Example: A student with social anxiety may avoid crowded cafeterias or eye contact with professors to reduce anxiety.

Panic Attack Cycle: Individuals may notice increased heart rate, which leads to fear of experiencing a panic attack, perpetuating the cycle.

Cycle of panic attacks

Obsessive-Compulsive Disorder (OCD)

OCD is characterized by persistent, unwanted thoughts (obsessions) and repetitive, ritualistic behaviors (compulsions) performed to reduce anxiety. Common obsessions include fears of contamination, while compulsions may involve excessive cleaning or checking. The disorder is associated with dysfunction in the orbitofrontal cortex (OFC), basal ganglia, and thalamus, as well as the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC).

Obsessions: Intrusive thoughts that cause distress (e.g., fear of germs).
Compulsions: Ritualistic behaviors aimed at reducing anxiety (e.g., handwashing).
Neural Circuits: The orbitofrontal loop (OFC → basal ganglia → thalamus) is implicated in OCD, along with the DLPFC and ACC.

Prefrontal cortex regions involved in OCD Anterior cingulate cortex location

Example: The "Lady Macbeth effect" refers to the urge to cleanse oneself after moral transgressions, illustrating the link between obsessions and compulsions.

Mood Disorders

Mood disorders involve significant disturbances in emotional state. The two primary types are major depressive disorder (MDD) and bipolar disorder. These disorders affect mood, motivation, energy, and cognitive functioning.

Major Depressive Disorder (MDD): Characterized by prolonged sadness, feelings of worthlessness, hopelessness, social withdrawal, and cognitive/physical sluggishness. Individuals may exhibit a pessimistic explanatory style, attributing negative events to internal, stable, and global causes.
Biological Factors: Overactivity of the amygdala and hypothalamic-pituitary-adrenal (HPA) axis, reduced inhibition by the hippocampus and frontal cortex, and decreased neurogenesis in the hippocampus. The nucleus accumbens is involved in anhedonia (loss of pleasure), and the medial prefrontal cortex (mPFC) is linked to rumination.
Neurochemistry: Serotonin (5-HT) deficits are common; selective serotonin reuptake inhibitors (SSRIs) are used as treatment.
Bipolar Disorder: Involves alternating periods of mania (elevated mood, energy) and depression. It is challenging to treat due to the extreme mood fluctuations.

Cortisol molecule and stress Neurobiology of depression and HPA axis Pessimistic explanatory style in depression

Example: A person with MDD may withdraw from social activities and experience persistent negative thoughts about themselves and their future.

Schizophrenia

Symptoms and Phases

Schizophrenia is a severe brain disorder characterized by significant breaks from reality, disorganized thinking, and problems with attention and memory. It is distinct from dissociative identity disorder (DID). The disorder progresses through several phases:

Prodromal Phase: Marked by negative symptoms such as social withdrawal and catatonia.
Active Phase: Characterized by positive symptoms, including hallucinations (false perceptions) and delusions (false beliefs, e.g., paranoia or grandeur), as well as disorganized behavior.
Residual Phase: Symptoms may lessen but some impairment remains.
Subtypes: Paranoid, disorganized, and catatonic forms exist.

Scene from A Beautiful Mind illustrating schizophrenia

Example: Hallucinations may involve hearing voices that are not present, while delusions may include beliefs of being persecuted or having special powers.

Explanations: Biological and Environmental Factors

Multiple factors contribute to the development of schizophrenia, including genetics, brain structure, neurochemistry, and environmental stressors.

Genetics: Family and twin studies show a strong genetic component. The risk increases with closer genetic relationships to affected individuals.
Brain Differences: Enlarged ventricles, reduced frontal cortex activity, increased dopamine (DA) activity (positive symptoms), and underactive glutamate (GLU) systems (negative symptoms) are observed.
Neurodevelopmental Hypothesis: Prenatal factors (e.g., maternal stress, malnutrition) and adolescent factors (e.g., excessive synaptic pruning in the prefrontal cortex) increase risk.
Environmental Stressors: Urban living, low social support, high emotional expressiveness (EE), and cannabis use are associated with increased risk.

Brain ventricle size in schizophrenia Genetic risk of schizophrenia Neurodevelopmental timeline and schizophrenia risk factors Environmental and developmental risk factors for schizophrenia

Example: A person with a family history of schizophrenia who experiences urban stress and cannabis use during adolescence may be at higher risk for developing the disorder.

Additional Resources

York University Student Counselling, Health & Well-being: https://students.yorku.ca/counselling
Good2Talk: 1-866-925-5454 or text GOOD2TALKON to 686868