Overview of Psychological Disorders and Their Classifications

Psychopathology

Study of psychological disorders, including symptoms, causes (etiology), and treatment.

Psychological disorder

Abnormal thoughts, feelings, or behaviors that are atypical, dysfunctional, or dangerous.

Defining Criteria (APA definition)

Significant disturbances in thoughts, emotions, or behavior that reflect biological, psychological, or developmental dysfunction, cause significant distress or disability, and are outside cultural expectations.

Cultural Influence

Cultural norms vary: hallucinations might be seen as pathology in one culture and spiritual in another.

Harmful Dysfunction (Wakefield, 1992)

Disorder = dysfunction in a mental mechanism + harmful consequences judged by cultural standards.

DSM-5

Diagnostic and Statistical Manual of Mental Disorders published by APA, listing disorders, diagnostic criteria, features, prevalence, risk factors, and comorbidity.

ICD

International Classification of Diseases published by WHO, similar to DSM but more used internationally and in public health.

Supernatural Perspective

Disorders seen as possession, witchcraft, or curses, with treatments including exorcism, torture, and punishment.

Biological Perspective

Disorders linked to genetics, brain chemistry, or structure.

Diathesis-Stress Model

Disorders result from a vulnerability (diathesis) + environmental stress, combining biological and psychosocial causes.

Anxiety Disorders

Excessive, persistent fear or anxiety; most common class of disorders (~25-30% lifetime prevalence).

Specific Phobia

Irrational fear of specific objects/situations (e.g., spiders, heights) affecting 12.5% of the population.

Social Anxiety Disorder

Extreme fear of social judgment linked to past teasing and behavioral inhibition, often comorbid with alcohol abuse.

Panic Disorder

Recurrent unexpected panic attacks + fear of future attacks, caused by genetics, brainstem (locus coeruleus), and catastrophic thinking.

Generalized Anxiety Disorder (GAD)

Persistent, excessive worry lasting 6+ months, caused by cognitive patterns from trauma or maltreatment.

Obsessive-Compulsive Disorder (OCD)

Characterized by obsessions (intrusive, unwanted thoughts) and compulsions (ritualistic behaviors to relieve obsession distress), with a prevalence of 2.3%.

Causes of OCD

Higher prevalence among first-degree relatives, overactive orbitofrontal cortex, and classical/operant conditioning creating compulsions as negative reinforcement.

Body Dysmorphic Disorder

Obsession with imagined physical flaws.

Hoarding Disorder

Difficulty discarding possessions.

Posttraumatic Stress Disorder (PTSD)

Triggered by exposure to trauma.

PTSD Symptoms

Flashbacks, avoidance, negative emotions, hyperarousal.

PTSD Prevalence

Affects ~7% of population.

PTSD Risk Factors

Trauma involving harm by others, low support, childhood adversity, serotonin gene variant.

Major Depressive Disorder (MDD)

Intense sadness, anhedonia, fatigue, worthlessness, suicidal thoughts.

MDD Prevalence

Affects ~6.6% annually, ~17% lifetime.

MDD Gender Differences

More common in women.

MDD Subtypes

Seasonal, postpartum, persistent depressive disorder (dysthymia).

Bipolar Disorder

Alternates between depression and mania.

Bipolar Manic Symptoms

Talkative, reckless, little sleep, grandiosity.

Bipolar Prevalence

Affects ~1% of population.

Biological Basis of Mood Disorders

High heritability, especially for bipolar.

Cortisol and Depression

Elevated cortisol linked to depression.

Neurotransmitters in Depression

Low serotonin/norepinephrine in depression; dopamine also involved.

Brain Structure in Depression

Overactive amygdala, underactive prefrontal cortex in depression.

Aaron Beck's Theory

Depressive schemas from early experiences → cognitive biases.

Hopelessness Theory

Stable, global, and internal attributions → hopelessness → depression.

Rumination

Repetitive negative focus sustains depression (more common in women).

Suicide and Mental Illness

90% of those who die by suicide have a diagnosable mental illness.

Suicide Risk Factors

Substance abuse, access to lethal means, isolation, prior attempts.

Gender Differences in Suicide

Males 4x more likely to die by suicide.

Schizophrenia Prevalence

Affects ~1% of population.

Positive Symptoms of Schizophrenia

Hallucinations, delusions, disorganized thinking.

Negative Symptoms of Schizophrenia

Avolition, anhedonia, asociality, alogia.

Genetics of Schizophrenia

Highly heritable.

Dopamine Hypothesis

Overactive dopamine systems.

Brain Structure in Schizophrenia

Enlarged ventricles, reduced frontal lobe activity.

Prenatal Factors in Schizophrenia

Infection, stress.

Dissociative Amnesia

Loss of memory tied to trauma.

Depersonalization/Derealization Disorder

Feeling detached from self or surroundings.

Dissociative Identity Disorder (DID)

Two or more distinct personalities; often linked to childhood trauma.

Personality Disorders

Enduring, inflexible patterns that impair functioning.

Personality Disorders Prevalence

Affects ~9% of population.

Cluster A Personality Disorders

Paranoid, schizoid, schizotypal.

Cluster B Personality Disorders

Borderline Personality Disorder, Antisocial Personality Disorder.

Borderline Personality Disorder

Instability in mood, relationships, self-image; linked to childhood abuse.

Antisocial Personality Disorder

Lack of empathy, deceitful, impulsive; common in males; linked to genetics and brain abnormalities.

Cluster C Personality Disorders

Avoidant, dependent, obsessive-compulsive.

ADHD (Attention-Deficit/Hyperactivity Disorder)

Inattention + hyperactivity/impulsivity.

ADHD Prevalence

Affects ~5% of children, more boys.

Causes of ADHD

Genetic, dopamine deficiency, frontal lobe underactivity.

Autism Spectrum Disorder

Deficits in social interaction, communication, and repetitive behaviors.

Causes of Autism Spectrum Disorder

Genetic + environmental factors (e.g., mutations).