1. Major Depressive Disorder (MDD)

Category: Depressive Disorders
Prevalence: ~7% annually (U.S.)
Core Features: Persistent sadness or loss of interest

Symptoms:

• Depressed mood most of the day

• Anhedonia (loss of interest)

• Sleep changes

• Appetite/weight change

• Fatigue

• Feelings of worthlessness

• Difficulty concentrating

• Suicidal thoughts

Treatment:

• SSRIs (e.g., fluoxetine)

• Cognitive Behavioral Therapy (CBT)

• Lifestyle interventions (exercise, sleep)

• Electroconvulsive therapy (severe cases)

2. Generalized Anxiety Disorder (GAD)

Category: Anxiety Disorders
Prevalence: ~3% annually

Core Features: Excessive, uncontrollable worry for at least 6 months

Symptoms:

• Restlessness

• Fatigue

• Difficulty concentrating

• Irritability

• Muscle tension

• Sleep disturbance

Treatment:

• CBT

• SSRIs or SNRIs

• Buspirone

• Relaxation techniques and mindfulness

3. Bipolar I Disorder

Category: Bipolar and Related Disorders
Prevalence: ~1% lifetime

Core Features: At least one manic episode (may include depressive episodes)

Symptoms (Manic Episode):

• Elevated or irritable mood

• Increased energy/activity

• Decreased need for sleep

• Grandiosity

• Pressured speech

• Risky behavior

Treatment:

• Mood stabilizers (e.g., lithium)

• Antipsychotics

• Psychoeducation

• Therapy (e.g., family-focused)

4. Schizophrenia

Category: Schizophrenia Spectrum and Other Psychotic Disorders
Prevalence: ~1% lifetime

Core Features: Psychosis lasting ≥6 months, including delusions, hallucinations

Symptoms:

• Positive: delusions, hallucinations, disorganized speech

• Negative: flat affect, social withdrawal

• Cognitive: poor executive function

Treatment:

• Antipsychotics (e.g., risperidone)

• Psychosocial interventions

• Supported employment/housing

• Cognitive remediation therapy

5. Obsessive-Compulsive Disorder (OCD)

Category: Obsessive-Compulsive and Related Disorders
Prevalence: ~1–2% annually

Core Features: Recurrent, intrusive thoughts (obsessions) and repetitive behaviors (compulsions)

Examples:

• Obsessions: contamination, harm, symmetry

• Compulsions: hand-washing, checking, counting

Treatment:

• SSRIs (high doses)

• Exposure and Response Prevention (ERP)

• CBT

• Deep brain stimulation (severe/refractory)

6. Post-Traumatic Stress Disorder (PTSD)

Category: Trauma- and Stressor-Related Disorders
Prevalence: ~3.5% annually

Core Features: Trauma exposure + intrusive memories, avoidance, hyperarousal

Symptoms:

• Flashbacks/nightmares

• Avoidance of reminders

• Negative mood/cognition

• Hypervigilance, exaggerated startle

Treatment:

• Trauma-focused CBT

• EMDR (Eye Movement Desensitization and Reprocessing)

• SSRIs

• Prazosin (for nightmares)

7. Attention-Deficit/Hyperactivity Disorder (ADHD)

Category: Neurodevelopmental Disorders
Prevalence: ~5% children, ~2.5% adults

Core Features: Inattention and/or hyperactivity-impulsivity before age 12

Symptoms:

• Easily distracted

• Fidgeting

• Interrupting

• Poor organization

• Forgetfulness

Treatment:

• Stimulants (e.g., methylphenidate)

• Behavioral therapy

• School accommodations

• Parent training

8. Borderline Personality Disorder (BPD)

Category: Personality Disorders (Cluster B)
Prevalence: ~1.6% (up to 5.9% lifetime)

Core Features: Instability in interpersonal relationships, self-image, and affect

Symptoms:

• Intense fear of abandonment

• Emotional lability

• Identity disturbance

• Impulsivity

• Self-harm or suicidal behavior

Treatment:

• Dialectical Behavior Therapy (DBT)

• Psychodynamic therapy

• SSRIs (for mood symptoms)

• Hospitalization (during crises)

9. Social Anxiety Disorder (Social Phobia)

Category: Anxiety Disorders
Prevalence: ~7% annually

Core Features: Fear of social or performance situations

Symptoms:

• Avoidance of speaking, eating, or performing publicly

• Fear of embarrassment or humiliation

• Physical symptoms: blushing, sweating, trembling

Treatment:

• CBT (exposure therapy)

• SSRIs or SNRIs

• Beta-blockers (for performance anxiety)

• Social skills training

10. Substance Use Disorders (SUDs)

Category: Substance-Related and Addictive Disorders
Prevalence: ~8% annually (any SUD in the U.S.)

Core Features: Problematic use of a substance leading to impairment or distress

Substances:

• Alcohol, opioids, cannabis, stimulants, etc.

Symptoms:

• Craving

• Loss of control

• Tolerance/withdrawal

• Continued use despite harm

Treatment:

• Motivational Interviewing

• Medication-assisted treatment (e.g., buprenorphine, naltrexone)

• CBT

• 12-step programs (e.g., AA)