1. Signs and Symptoms
1.1. Emotional/Psychological Symptoms
1.1.1. Persistent sadness, hopelessness
1.1.2. Irritability/frustration
1.1.3. Loss of interest or pleasure in activities (anhedonia)
1.1.4. Feeling of worthlessness, guilt or helplessness
1.1.5. Recurrent thoughts of death, suicidal ideation
1.2. PHYSICAL SYMPTOMS
1.2.1. Fatigue
1.2.2. Changes in appetite leading to weight loss
1.2.3. Insomia
1.2.4. Unexplained Headaches and back pain
1.3. Behavioural symptoms
1.3.1. Neglect of responsibilities (work school or home)
1.3.2. Social withdrawal
1.3.3. Reduced motivation
2. SYSTEM AFFECTED
2.1. Central Nervous System
2.1.1. Impaired memory, concentration and decision makinga
2.1.2. Decreased neuroplasticity and neurogenesis
2.1.3. Increased risk for neurodegenerative disorders (Alzheimers)
2.2. CARDIOVASCULAR SYSTEM
2.2.1. Increase risk of hypertension and heart disease
2.2.2. Increase inflammatory markers (CRP) contributing to atherosclerosis
2.2.3. Poor heart rate variability leading to increase of arrhythmias
2.2.4. Elevated cortisol and catecholamines
2.3. Respiratory System
2.3.1. Slowed or irregular breathing pattern
2.3.2. Higher risk of poor respiratory outcomes in comorbid illness (COPD)
2.4. GASTROINTESTINAL SYSTEM
2.4.1. Appetite changes: weight gain/loss
2.4.2. Constipation
2.4.3. Nausea and abdominal pain
2.5. Musculoskeletal system
2.5.1. Chronic fatigue, decreased physical activity
2.5.2. Muscle aches and joint pain
2.5.3. Increased perception of pain
2.6. Endocrine & Immune System
2.6.1. Dysregulation of HPA axis leading to increased cortisol
2.6.2. Decrease immune response leading to increased susceptible to infections
2.6.3. Increased Systemic inflammation
3. Complications
3.1. Suicidal ideation / attempts
3.2. Substance abuse
3.3. Poor adherence to medication
3.4. Worsening of chronic disease (DM, HTN)
3.5. Social withdrawal
3.6. Malnutrition
3.7. Sleep disorder
4. Diagnostic test
4.1. CLINICAL EVALUATION PRIMARY TOOL)
4.1.1. Psychiatric assessment using
4.1.2. DSM-5 criteria for major depressive disorder (MDD)
4.1.3. Structured interviews (PHQ-9, HAM-D)
4.1.4. Suicide risk assessment.
4.2. LAB TEST
4.2.1. Complete Blood count to rule out anaemia and infection
4.2.2. Comprehensive metabolic panel to evaluate liver and kidney function
4.2.3. Thyroid function test hypo or hyperthyroidism can mimic depression
4.2.4. Hormonal and endocrine panel
4.2.5. Vitamin B12 and folate, Vitamin D levels, HbA1c or fasting glucose
4.2.6. Cortisol level
4.2.7. Toxicology screen(Urine drug screen) : identify substance use that may mimic depression
4.3. IMAGING
4.3.1. Brain MRI or CT scan
4.3.1.1. Use when symptoms are atypical, late onset or suggest a neurological issue
5. Treatment Options
5.1. Pharmacological
5.1.1. First line Antidepressants (SSRIs)
5.1.1.1. Fluoxetine, sertraline, citalopram, escitalopram, paroxetine
5.1.1.1.1. Well tolerated and effective. and Monitor for suicidal thoughts, serotonin syndrome, GI side effects.
5.1.2. Other Antidepressants (2nd line or if SSRIs are ineffective)
5.1.2.1. Duloxetine, Mirtazapine
5.1.3. TCAs/MAOIs: older, more side effects, used when other fails
5.1.4. Adjunctive medications ( for treatment of resistant depression)
5.1.5. Atypical antipsychotics (Aripiprazole, quetiapine)
5.1.6. Mood stabilizers ( Lamotrigine, lithium)
5.2. Non pharmacological
5.2.1. Psychotherapy
5.2.1.1. Effective alone for mild/moderate depression or combined with meds in moderate/severe cases
5.2.2. Cognitive behavioral therapy
5.2.3. Dialectical behavioral therapy
5.2.4. Psychodynamic therapy
5.2.5. Group therapy/ support group
5.3. Advanced/ NON pharmacological options
5.3.1. Electroconvulsive therapy
5.3.1.1. rapid and effective for severe, suicidal or catatonic depression.
5.3.2. Transcranial magnetic Stimulation
5.3.2.1. Non invasive, outpatient brain stimulation
5.3.3. Ketamine:
5.3.3.1. fast acting NMDA antagonist for severe depression
6. DEFINITION AND PATHOPHYSIOLOGY
6.1. Neurotransmitter Dysregulation
6.1.1. Reduced Norepinephrine (energy, alertness)
6.1.2. Reduced serotonin (Mood, sleep, appetite regulation)
6.1.3. Reduced Dopamine (Pleasure, reward)
6.2. Hypothalamic Pituitary Adrenal (HPA) Axis Dysfunction
6.2.1. Increase cortisol levels due to chronic stress
6.2.2. Impaired feedback loop between brain and adrenal glands
6.3. Neuroplasticity & Neurogenesis Impairment
6.3.1. Decreased brain derived neurotrophic factor (BDNF)
6.3.2. Reduced neurogenesis in hippocampus
6.3.3. Decreased synaptic connectivity
6.4. Structural brain changes
6.4.1. Decreased volume in Prefrontal cortex (decision making)
6.4.2. Hippocampus (memory)
6.4.3. Amygdala ( emotion regulation)
6.5. Inflammatory Response
6.5.1. Increased pro inflammatory cytokines (eg, IL-6, TNF-alpha)
6.5.2. Possible link between systemic inflammation and depressive symptoms
6.6. Circadian Rhythm Diruption
6.6.1. Abnormal sleep wake cycles
6.6.2. Melatonin and cortisol rhythm disturbances
7. CAUSES
7.1. Biological Factors and genetic factors
7.1.1. Genetic predisposition (Family history of mood disorders)
7.1.2. Imbalance in brain chemicals (neurotransmitters)
7.1.3. Chronic medical conditions (DM, cardiovascular disease)
7.2. Psychological factors
7.2.1. Negative thought patterns (cognitive distortions)
7.2.2. Low self esteem or poor coping mechanisms
7.2.3. Early childhood trauma or loss
7.3. Environmental & Social factors
7.3.1. Stressful life events (loss, divorce or job stress)
7.3.2. Stressful life events (loss, divorce or job stress)
7.3.3. Lack of social support
7.3.4. Substance abuse
7.4. Hormonal factors
7.4.1. Postpartum changes
7.4.2. Menopause
7.4.3. Thyroid dysfunction
7.5. Medication or Substance Use
7.5.1. Side effect of certain medications ( steroids, beta-blockers)
7.5.2. Alcohol or drug use contributing to mood changes
8. RISK FACTOR
8.1. Psychological Risk Factors
8.1.1. Low self esteem
8.1.2. Negative thinking patterns (hopelessness, rumination)
8.1.3. History of trauma or abuse (emotional, physical, or sexual)
8.1.4. Poor coping skills
8.1.5. Anxiety disorders or other psychiatric comorbidities (PTSD, OCD)
8.2. Environmental & Social RIsk Factors
8.2.1. Stressful life events (Job loss, divorce)
8.2.2. Social isolation or loneliness
8.2.3. Lack of social or family support
8.2.4. Lack of social or family support
8.2.5. Financial difficulties or poverty
8.2.6. Living in a high conflict or abusive environment
8.3. Substance Use & Medications
8.3.1. Alcohol or drug misuse
8.3.2. Withdrawal from substances (alcohol, stimulants)
8.3.3. Medications (benzodiazepines)
8.3.4. Medications (benzodiazepines)
8.4. Developmental & Early life Factors
8.4.1. Adverse childhood experiences (ACEs)
8.4.2. Parental neglect or absence
8.4.3. Early loss of a parent or caregiver
9. POSSIBLE REFERRAL
9.1. Psychiatrist
9.2. psychologist
9.3. therapist
9.4. Endocrinologist
9.5. Nutritionist,
9.6. Social worker
10. AFFECTED IN BRAIN
10.1. Serotonin (5-HT)
10.1.1. Origin:Raphe nuclei (brainstem)
10.1.1.1. Affected: mood regulation, sleep wake cycle, appetite, sexual desire, impulse control
10.1.1.2. Limbic system ( emotion regulation)
10.1.1.3. Hypothalamus ( appetite, sleep)
10.1.1.4. Prefrontal cortex (mood, decision manking)
10.2. Noreephinephrine
10.2.1. Origin : locus coeruleus (pons)
10.3. Dopamine
10.3.1. Origin: Ventral tegmental are
10.4. Also affected prefrontal cortex
10.5. Anterior cingulate cortex
10.6. Amygdala
10.7. Thalamus
10.8. Basal ganglia
10.9. Hypothalamus
10.10. Hippocampus
11. PATIENT CONSIDERATION
11.1. GENETIC COUNSELING
11.1.1. Family history of depression
11.1.2. Involves polygenic inheritance
11.1.3. Consider pharmacogenetic testin
11.2. FAMILY IMPACT
11.2.1. Can strain family relationship
11.2.2. Children of depressed parent at risk of emotional issues
11.2.3. Caregiver fatigue
11.3. CULTURAL FACTORS
11.3.1. stigma may delay seeking treatment
11.3.2. Language barrier can interfere with diagnosis and treatment
11.3.3. spiritual beliefs may influence hoe symptoms are perceived