Major Depressive Disorder - Psychiatry

Snapshot
A 51-year-old female presents to her PCP with a sore throat. Upon further screening, the patient shares concerns of difficulty with sleep, concerns about making mistakes in her life, and observations of decreased ability to focus at work as an administrative assistant for the past three months. She occasionally feels anxious about repeating past mistakes, which she cannot articulate. She goes on to express guilt about the death of some of her family members. She reports having experienced bouts of intense energy and uncontrollable thinking during which she felt very productive at work without need for sleep just prior to her current state. She denies any suicidal or homicidal thoughts. She denies any family history of depression or bipolar disorder. She denies worsened symptoms with menses. Physical exam is unremarkable, but the patient remarks a low appetite that has led to 3 pounds of weight loss. The PCP diagnoses the woman with major depressive disorder with mixed features and with anxious distress. The patient is started on escitalopram and scheduled for a follow-up appointment in two weeks.
Introduction
Mood state, syndrome, and/or mental disorder characterized by dysphoria (sad/irritable) Most common psychiatric disorder Epidemiology 18% prevalence in the United States females affected twice as often as males not associated with economic status or race incidence decreases with increasing age however, associated with presence of multiple medical comorbidities Classifications (DSM-V) unipolar major depression (major depressive disorder) persistent depressive disorder (previously called dysthymia) no scientifically meaningful distinction between chronic depression and dysthymia symptom persistence for > 2 years disruptive mood dysregulation disorder new diagnosis for children up to 18 years with persistent irritability and behavior dyscontrol created due to concerns of overdiagnosis of bipolar disorder premenstrual dysphoric disorder substance/medication induced depressive disorder depressive disorder due to another medical condition unspecified depressive disorder
Presentation
Symptoms SIG E CAPS Sleep decreased Interest decreased (anhedonia) Guilt increased Energy decreased Concentration decreased Appetite decreased Psychomotor retardation Suicidal ideations

Evaluation

Routine outpatient screening now recommended by USPSTF
- Patient Health Questionnaire-2 (PHQ-2) can be used
  - if positive, follow up with PHQ-9
  - assess for suicidal ideation, plan, and intent

Diagnostic criteria
- core symptom criteria have not changed in DSM-V
- one or more major depressive episodes
  - a depressive episode must contain five or more of the above symptoms
- for episodes > 2 week period separated by 2 month period
- impairment of daily living
- medical causes has been ruled out (e.g., hypothyroidism, adrenal insufficiency, Huntington's disease, hypercortisolism, mononucleosis, Parkinson's disease, stroke, lupus, TBI, vitamin B12 deficiency)
Subtype specifiers
- anxious distress
- atypical features
  - appetite increased
  - reactive to pleasurable stimuli
  - hypersomnia
  - heavy feelings in limbs
  - longstanding pattern of hypersensitivity to rejection
- catatonia
  - symptoms improve with benzodiazepines (i.e., lorazepam)
- mixed features
  - at least three symptom criteria for mania/hypomania

Treatment

Routine outpatient screening now recommended by USPSTF Patient Health Questionnaire-2 (PHQ-2) can be used if positive, follow up with PHQ-9 1st line: psychotherapy + pharmacotherapy psychotherapy cognitive-behavioral therapy or interpersonal psychotherapy pharmacotherapy selective serotonin reuptake inhibitors (SSRI) first line drug fewer side effects overall need at least 6-8 weeks to take effect SNRI, atypical agents (bupropion, mirtazapine) second line drugs TCAs and MAO inhibitors third line Electroconvulsive therapy for refractory cases, depression with psychotic features, or if immediate symptom resolution is required
Prognosis
Prognosis medical therapy effective in up to 70% of patients though must allow sufficient time for success and treat for minimum of 6 months results observable typically in 2 weeks follow-up usually at 2 weeks because risk of suicide is greatest following initial use of antidepressants if patient has had 1 episode of major depression, pharmacotherapy can be discontinued after 6 months of no symptoms can be monitored using PHQ-9 (not PHQ-2) complications pseudodementia dementia secondary to depression rule out organic causes before making this diagnosis (such as a TSH level)

Blood, Plasma, Serum	Reference Range
ALT	8-20 U/L
Amylase, serum	25-125 U/L
AST	8-20 U/L
Bilirubin, serum (adult) Total // Direct	0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca²⁺)	8.4-10.2 mg/dL
Cholesterol, serum	Rec: < 200 mg/dL
Cortisol, serum	0800 h: 5-23 μg/dL //1600 h: 3-15 μg/dL 2000 h: ≤ 50% of 0800 h
Creatine kinase, serum	Male: 25-90 U/L Female: 10-70 U/L
Creatinine, serum	0.6-1.2 mg/dL
Electrolytes, serum
Sodium (Na⁺)	136-145 mEq/L
Chloride (Cl^-)	95-105 mEq/L
Potassium (K⁺)	3.5-5.0 mEq/L
Bicarbonate (HCO₃^-)	22-28 mEq/L
Magnesium (Mg²⁺)	1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)
24-28 wks // 32-36 wks	30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks	40-220 ng/mL // 80-350 ng/mL
Ferritin, serum	Male: 15-200 ng/mL Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma	Male: 4-25 mIU/mL Female: premenopause: 4-30 mIU/mL midcycle peak: 10-90 mIU/mL postmenopause: 40-250
pH	7.35-7.45
PCO₂	33-45 mmHg
PO₂	75-105 mmHg
Glucose, serum	Fasting: 70-110 mg/dL 2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation	Fasting: <5 ng/mL Provocative stimuli: > 7ng/mL
Immunoglobulins, serum
IgA	76-390 mg/dL
IgE	0-380 IU/mL
IgG	650-1500 mg/dL
IgM	40-345 mg/dL
Iron	50-170 μg/dL
Lactate dehydrogenase, serum	45-90 U/L
Luteinizing hormone, serum/plasma	Male: 6-23 mIU/mL Female: follicular phase: 5-30 mIU/mL midcycle: 75-150 mIU/mL postmenopause 30-200 mIU/mL
Osmolality, serum	275-295 mOsmol/kd H₂O
Parathyroid hormone, serume, N-terminal	230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C)	20-70 U/L
Phosphorus (inorganic), serum	3.0-4.5 mg/dL
Prolactin, serum (hPRL)	< 20 ng/mL
Proteins, serum

Hematologic	Reference Range
Bleeding time	2-7 minutes
Erythrocyte count	Male: 4.3-5.9 million/mm³ Female: 3.5-5.5 million mm³
Erythrocyte sedimentation rate (Westergren)	Male: 0-15 mm/h Female: 0-20 mm/h
Hematocrit	Male: 41%-53% Female: 36%-46%
Hemoglobin A1c	≤ 6 %
Hemoglobin, blood	Male: 13.5-17.5 g/dL Female: 12.0-16.0 g/dL
Hemoglobin, plasma	1-4 mg/dL
Leukocyte count and differential
Leukocyte count	4,500-11,000/mm³
Segmented neutrophils	54%-62%
Bands	3%-5%
Eosinophils	1%-3%
Basophils	0%-0.75%
Lymphocytes	25%-33%
Monocytes	3%-7%
Mean corpuscular hemoglobin	25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration	31%-36% Hb/cell
Mean corpuscular volume	80-100 μm³
Partial thromboplastin time (activated)	25-40 seconds
Platelet count	150,000-400,000/mm³
Prothrombin time	11-15 seconds
Reticulocyte count	0.5%-1.5% of red cells
Thrombin time	< 2 seconds deviation from control
Volume
Plasma	Male: 25-43 mL/kg Female: 28-45 mL/kg
Red cell	Male: 20-36 mL/kg Female: 19-31 mL/kg

Cerebrospinal Fluid	Reference Range
Cell count	0-5/mm³
Chloride	118-132 mEq/L
Gamma globulin	3%-12% total proteins
Glucose	40-70 mg/dL
Pressure	70-180 mm H₂O
Proteins, total	< 40 mg/dL

Sweat	Reference Range
Chloride	0-35 mmol/L
Urine
Calcium	100-300 mg/24 h
Chloride	Varies with intake
Creatinine clearance	Male: 97-137 mL/min Female: 88-128 mL/min
Estriol, total (in pregnancy)
30 wks	6-18 mg/24 h
35 wks	9-28 mg/24 h
40 wks	13-42 mg/24 h
17-Hydroxycorticosteroids	Male: 3.0-10.0 mg/24 h Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total	Male: 8-20 mg/24 h Female: 6-15 mg/24 h
Osmolality	50-1400 mOsmol/kg H₂O
Oxalate	8-40 μg/mL
Potassium	Varies with diet
Proteins, total	< 150 mg/24 h
Sodium	Varies with diet
Uric acid	Varies with diet
Body Mass Index (BMI)	Adult: 19-25 kg/m²