History

• Patients do not always present with a straightforward complaint of feeling depressed ^r11
• Vague somatic complaints or numerous complaints that do not fit any clear clinical pattern often occur, particularly in older patients and in patients for whom psychological symptoms are stigmatized ^r11
  • Fatigue ^c1
  • Poor concentration ^c2
  • Memory impairment ^c3
  • Difficulty making day-to-day decisions ^c4
  • Decline in school or work performance ^c5c6
  • Decreased sexual interest ^c7
  • Sleep disturbance ^c8
  • Appetite changes ^c9
  • Weight changes (gain or loss) ^c10c11c12
  • Headache ^c13
  • Nausea ^c14
  • Pain ^c15
  • Change in bowel habits (constipation or diarrhea) ^c16c17c18
• Depressive symptoms ^r9
  • Loss of interest or pleasure in previously enjoyable things ^c19
  • Disproportionate feelings of guilt or thoughts of worthlessness ^c20c21c22
  • Suicidal thoughts or thoughts about dying ^c23c24
  • Psychotic symptoms (particularly in older patients) ^c25c26
  • Anxiety and worry ^c27c28
  • Preoccupation with physical complaints ^c29

Physical examination

• Psychological findings ^r9
  • Depressed or flat affect ^c30c31
  • Appears withdrawn, with poor eye contact ^c32c33
  • Psychomotor agitation or retardation ^c34c35
  • Crying ^c36
  • Anxious behavior ^c37
  • Irritability ^c38
  • Evidence of self-neglect with poor personal hygiene ^c39c40
• Dermatologic findings ^r11
  • Evidence of self-harm (eg, healed lacerations, scars on body or extremities) ^c41c42c43
• Weight loss, weight gain, or evidence of poor nutrition ^r11c44

Causes

• Unknown ^c45

Risk factors and/or associations

Primary diagnostic tools

• Depression screening tools (eg, Beck Depression Inventory, Patient Health Questionnaire-9) can be used initially to identify patients requiring full diagnostic interviews using standard diagnostic criteria ^r1r2r4r11
• History and physical examination provide definitive diagnosis ^c58
• Laboratory analyses (eg, hypothyroidism testing [TSH], urine or serum drug screen) can be used to exclude medical disorders that produce or exacerbate mood symptoms or screen for substance-induced mood symptoms ^r13c59c60

Other diagnostic tools

• Standardized depression inventory tests ^c61
  • US Preventive Services Task Force recommends the following: "All positive screening results should lead to additional assessment that considers severity of depression and comorbid psychological problems (eg, anxiety, panic attacks, or substance abuse), alternate diagnoses, and medical conditions" ^r1
  • Beck Depression Inventory ^r2c62
    • Self-rated questionnaire
    • Measures the intensity, severity, and depth of common depression symptoms
    • Standard test has 21 questions; a shorter 7-question version is optimized for screening use in the office setting
  • Hamilton Depression Rating Scale ^r2c63
    • Observer-rated scale designed to be administered by the health care professional
  • Major Depression Inventory ^r3c64
    • Self-rated questionnaire
    • Incorporates both the ICD‐10 symptoms of depression and the DSM-IV symptoms of major depression
  • Patient Health Questionnaire-9 ^r4r14c65
    • Self-rated questionnaire with 9 items

Most common ^r15

• Persistent depressive disorder (dysthymia) ^c66
  • Characterized by:
    • Changes in eating
    • Altered sleeping pattern (eg, insomnia, hypersomnia)
    • Low energy
    • Low self-esteem
    • Inability to concentrate or make decisions
    • Feelings of hopelessness or pessimism
  • Fewer symptoms than major depressive disorder
  • Involves feeling depressed for periods of variable duration but without meeting DSM-5 criteria for major depressive disorder
  • Such patients often have major depressive disorder interspersed throughout their lifetime
  • Differentiated based on history and physical examination
• Bipolar disorder ^r16c67d1
  • Mood disorder characterized by episodes of mania or hypomania
  • Carefully screen patients with major depression for bipolar disorder
    • 15% of patients with major depression have bipolar disorder ^r17
    • Patients with bipolar disorder do not respond to antidepressants; therefore, differentiation is crucial
  • Presence of mania or hypomania is the cardinal feature that distinguishes bipolar disorder from major depressive disorder
    • Mania
      • A period of mood change (happy, excited, or irritable) that causes impairment and is distinct and noted by others
      • At least 4 of the following symptoms are present:
        • Inflated self-esteem or grandiosity
        • Little need for sleep (without development of fatigue)
        • Pressured or overly verbose speech
        • Racing thoughts
        • Distractibility
        • Irritability or agitation
        • Reckless or high-risk behavior
  • Differentiated based on history and physical examination
• Adjustment disorder ^r18c68
  • Temporary, short-term, nonpsychotic response to an event or situation (eg, a divorce, a death in the family, a disappointment, a failure)
  • Symptoms can include sadness, anxiety, insomnia, poor concentration, poor performance in school
  • Symptoms persist for no longer than 6 months after termination of the stressor
  • Does not meet criteria for another mental disorder
  • Differentiated based on history and physical examination
• Dementia ^r19c69
  • Especially in older patients, may be mistaken for major depressive disorder during early stages of the illness
  • The following features are more closely associated with dementia:
    • Impaired, inconsistent, and fluctuating orientation, mood, and behavior
    • Cognitive impairment that worsens over time
    • Neurologic deficits often present (eg, dysphasia, apraxia)
    • Disabilities concealed by the patient
    • Inability to remember recent events; often unaware of memory loss
    • Onset of memory loss occurs before mood change
    • Frequently uncooperative, confused, or disoriented
    • Demonstrated lack of concern about cognitive deficit
  • Differentiated based on history and physical examination
• Parkinson disease ^r20c70d2
  • Progressive disorder of the central nervous system that often coexists with depression
  • Associated with symptoms of major depressive disorder, in addition to:
    • Increased muscle tone with cogwheel rigidity
    • Coarse resting tremor
    • Akinesia
    • Loss of facial expression
    • Shuffling gait
    • Flexed posture
  • Differentiated based on history and physical examination
• Schizophrenia ^c71d3
  • Disorder that affects thoughts, feelings, and perceptions; primary symptom is psychosis with auditory hallucinations and delusions
  • Schizophrenic patients may develop secondary major depression ^r16
  • Distinguished from major depressive disorder by the following:
    • Severe personality deterioration
    • Thought disorder, including loose associations
    • Grandiose delusions
    • Hallucinations, which are typically auditory
    • Bizarre behavior
  • Differentiated based on history and physical examination
• Schizoaffective disorder ^c72
  • Milder psychotic symptoms than schizophrenia with presence of mood disorder ^r16
• Hypothyroidism ^r21c73d4
  • Patients with hypothyroidism may have symptoms of major depressive disorder, in addition to signs and symptoms of slow metabolism (eg, dry skin, brittle hair, weight gain)
  • Differentiated by laboratory testing for hypothyroidism
• Substance use disorders ^c74c75
  • May cause symptoms of depression with chronic use or from withdrawal
  • Causative substances include:
    • Alcohol ^c76c77d5
    • Stimulants (eg, amphetamine, cocaine) ^{c78c79c80c81c82c83d6}
    • Cannabis (with chronic use) ^c84c85
    • Opiates ^c86c87d7
    • Anabolic steroids ^c88c89
  • Differentiated from major depressive disorder by:
    • Positive result from urine or serum drug screen for the substance, if available
    • History of mood disorder that occurs temporally with substance use or withdrawal
• Medication causes ^r14c90
  • Drug classes that are known to produce symptoms similar to depression include:
    • Benzodiazepines ^c91
    • Steroids ^c92
    • Levodopa ^c93
    • Oral contraceptives ^c94
    • Interferon ^c95
  • Differentiated based on history and physical examination

Admission criteria ^r23

• Patients unable to take care of themselves at home
• Patients undergoing electroconvulsive therapy
• Suicidal/homicidal ideation with intention or overt suicide/homicide attempts
• Psychosis

Recommendations for specialist referral

• Refer to psychiatrist if patient exhibits any of the following:
  • Suicidal or homicidal ideation or attempts
  • Severe confusion, raising the question of dementia or delirium
  • Delusions or hallucinations
  • Substance use or dependence
  • Suspected bipolar disorder
  • Depression that has not responded to appropriate drug therapy

Drug therapy

• Selective serotonin reuptake inhibitors ^r30c96
  • Citalopram ^c97
    • Citalopram Hydrobromide Oral solution; Children and Adolescents 7 to 17 years: 10 mg PO once daily initially. Some experts recommend 20 mg/day PO in those 12 years and older. Clinical guidelines recommend to start with a low dose and titrate gradually, in 10 mg/day increments at 4-week intervals, but some studies titrate as often as every week. Effective dose: 20 mg/day PO. Usual Max: 40 mg/day. Max for CYP2C19 poor metabolizers: 20 mg/day due to risk for QT prolongation. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions.
    • Citalopram Hydrobromide Oral tablet; Adults 60 years and younger: 20 mg PO once daily initially. May increase dose after 1 week if clinically indicated. Citalopram capsules may be used for patients taking 30 mg/day. Usual Max: 40 mg/day. Max for CYP2C19 poor metabolizers: 20 mg/day due to risk for QT prolongation. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions.
    • Citalopram Hydrobromide Oral tablet; Adults older than 60 years: 20 mg PO once daily is the recommended and max dosage. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions.
  • Escitalopram ^r31r32c98
    • Escitalopram Oral solution; Children and Adolescents 12 to 17 years: The initial and recommended dose is 10 mg PO once daily. If needed, may increase to 20 mg/day after a minimum of 3 weeks, but a trial in adults suggested no additional benefit. Max: 20 mg/day PO. Periodically reassess the need for continued treatment.
    • Escitalopram Oral tablet; Adults: 10 mg PO once daily is the initial and recommended dose. If needed, may increase to 20 mg once daily after a minimum of 1 week, but one trial suggested no additional benefit. Max: 20 mg/day PO. Periodically reassess the need for continued treatment.
    • Escitalopram Oral tablet; Geriatric Adults: 10 mg PO once daily is the initial and recommended dose. Periodically reassess the need for continued treatment.
  • Fluoxetine ^c99
    • Fluoxetine Hydrochloride Oral solution [Depression/Mood Disorders]; Children and Adolescents 8 to 17 years: 10 to 20 mg PO once daily. An initial dose of 10 mg/day may be appropriate in lower weight children; increase to 20 mg/day after 1 week. Usual effective dose: 10 to 20 mg/day. May increase by 10 to 20 mg increments if response not sufficient; full effect may take 4 weeks or longer. Max: 60 mg/day. May divide daily dose into 2 doses (e.g., morning and noon) if the dosage is 20 mg/day or more.
    • Fluoxetine Hydrochloride Oral tablet [Depression/Mood Disorders]; Adults: 20 mg/day PO initially. May increase after several weeks by 10 to 20 mg as needed and tolerated. Consider lower dosages for geriatric adults. Max: 80 mg/day PO. May divide daily dose into 2 doses (e.g., morning and noon) if the dosage is 20 mg/day or more.
  • Paroxetine ^c100
    • Paroxetine Hydrochloride Oral tablet; Adults: 20 mg PO once daily initially, usually in the morning. May increase by 10 mg at weekly intervals. Max: 50 mg/day PO. DEBILITATED or GERIATRIC ADULTS: 10 mg PO once daily initially, may increase by 10 mg at a minimum of weekly intervals; Max: 40 mg/day PO.
    • Paroxetine Hydrochloride Oral tablet, extended-release; Adults: 25 mg PO once daily initially, usually in the morning. May increase by 12.5 mg at weekly intervals. Max: 62.5 mg/day PO. DEBILITATED or GERIATRIC ADULTS: 12.5 mg/day PO initially, May increase by 12.5 mg at weekly intervals; Max: 50 mg/day PO.
  • Sertraline ^r33c101c102
    • Evidence recommends that physicians use caution when prescribing sertraline in pediatric patients (if at all).
    • Sertraline Hydrochloride Oral solution; Children 6 to 11 years†: 12.5 mg to 25 mg/day PO initially. Begin with a low dose and titrate gradually in 12.5 to 25 mg/day increments at 4-week intervals until clinical response is achieved; some studies report titration in 25 mg to 50 mg/day increments as often as every 1 to 2 weeks. A dose of 50 mg/day PO is considered effective in some patients. Max: 200 mg/day PO.
    • Sertraline Hydrochloride Oral tablet; Children and Adolescents 12 to 17 years†: 25 to 50 mg/day PO initially. Begin with a low dose and titrate gradually in 12.5 to 25 mg/day increments at 4-week intervals until clinical response is achieved; some studies report titration in 25 mg to 50 mg/day increments as often as every 1 to 2 weeks. A dose of 50 mg/day PO is considered effective in some patients. Max: 200 mg/day PO.
    • Sertraline Hydrochloride Oral tablet; Adults: 50 mg PO once daily. A lower initial dose (25 mg PO once daily) may be used to minimize adverse effects. May increase at intervals of not less than 1 week. May initiate sertraline capsules in patients who have taken 100 mg or 125 mg for at least 1 week. Max: 200 mg/day PO.
  • Vilazodone ^r34r35
    • Has not received enough study to judge safety in older patients or in those with, or at high risk for, cardiovascular disease. ^r34
  • Vortioxetine ^r34r35
• Serotonin-norepinephrine reuptake inhibitors ^c103
  • Duloxetine ^c104
    • Duloxetine Oral capsule, gastro-resistant pellets; Adults: Initially, give 20 mg PO twice daily or 60 mg/day PO as a single dose or in 2 divided doses (i.e., 30 mg PO twice daily). Alternatively, give 30 mg/day PO for 1 week, then increase to 60 mg/day. Target maintenance dose: 60 mg/day; dividing doses may increase tolerability. Max: 120 mg/day PO, but more than 60 mg/day has not been shown to have an additional benefit.
  • Milnacipran ^c105
    • Milnacipran Hydrochloride Oral tablet; Adults: Initially, 12.5 to 25 mg PO twice daily. Based on individual response, the dose may be titrated to 100 mg PO twice daily. Max: 200 mg/day. In one trial of adult patients with diabetes mellitus type 2 and co-morbid depression, 72.6% of treated patients fulfilled criteria for antidepressant response according to the Beck Depression Inventory scale.
  • Venlafaxine ^c106
    • Venlafaxine Hydrochloride Oral tablet; Adults: 75 mg/day PO, given in 2 or 3 divided doses, initially. If needed, may increase by 75 mg/day no less than every 4 days. Outpatient Max: 225 mg/day PO, given in divided doses. Institutional Max: 375 mg/day PO, given in 3 divided doses.
    • Venlafaxine Hydrochloride Oral tablet, extended-release; Adults: 75 mg PO once daily, initially. Alternatively, 37.5 mg PO once daily for 4 to 7 days to allow for tolerability before increasing to 75 mg/day PO. If needed, may increase by 75 mg/day at intervals of no less than every 4 days. Venlafaxine besylate ER tablets may be used in patients who have taken at least 75 mg/day for 4 or more days in order to provide 112.5 mg or 225 mg PO once daily dosage. Recommended Max: 225 mg/day PO.
  • Levomilnacipran ^r34r35
    • Has not received enough study to judge safety in older patients or in those with, or at high risk for, cardiovascular disease. ^r34
  • Desvenlafaxine ^r36
• Noradrenergic and specific serotonin antidepressants ^c107
  • Mirtazapine ^r31c108
    • Do not use concomitantly with MAOIs.
    • Mirtazapine Oral tablet; Adults: 15 mg PO once daily at bedtime, initially. If needed, may titrate no sooner than every 1 to 2 weeks. Geriatric patients may need slower titration schedules. The effective dose range is 15 to 45 mg/day. Max: 45 mg/day PO.
• Noradrenergic and dopaminergic antidepressants ^c109
  • Bupropion ^c110
    • Bupropion Hydrochloride Oral tablet [Depression/Mood Disorders]; Children† and Adolescents† 6 years and older: Dosage not established. Suggested dosage ranges from 1.4 to 6 mg/kg/day PO, titrated upward slowly and administered in divided doses. In trials, the average effective dose is roughly 3 mg/kg/day PO; the maximum dosage is generally 250 to 300 mg/day PO. Safety data are not extensive; most patients have also been diagnosed with ADHD.
    • Bupropion Hydrochloride Oral tablet [Depression/Mood Disorders]; Adults: Initially, 100 mg PO twice daily; titrate after 3 days to 100 mg PO 3 times per day if needed; no single dose should exceed 150 mg.
    • Bupropion Hydrochloride Oral tablet, extended release 12 hour [Depression/Mood Disorders]; Adolescents†: Limited data are available. Dosing may be weight based or may use a non-weight based titration similar to adults. One trial used initial doses up to 2 mg/kg (not to exceed 100 mg) PO once daily in the morning, followed by gradual titration to 3 mg/kg/dose every morning with 2 mg/kg/dose every evening at dinner. If needed, further titration to 3 mg/kg/dose PO twice daily occurred. Single doses of bupropion SR could not exceed 150 mg/dose. Max dose: 6 mg/kg/day PO, in divided doses. Alternatively, give no more than 150 mg PO once daily in the morning; titrate after no less than 4 days up to 150 mg PO twice daily if needed. After several weeks, titrate to 200 mg PO twice daily if needed with doses at least 8 hours apart.
    • Bupropion Hydrochloride Oral tablet, extended release 12 hour [Depression/Mood Disorders]; Adults: Initially, 150 mg PO each morning; titrate after 4 days to 150 mg PO twice daily if needed. After several weeks, titrate to 200 mg PO twice daily if needed; administer doses at least 8 hours apart.
    • Bupropion Hydrochloride Oral tablet, extended release 24 hour [Depression/Mood Disorders]; Adults: Initially, 150 mg PO once daily in the AM; titrate after 4 days to usual target dose of 300 mg PO once daily in the AM. Due to a dose-related risk of seizures, gradually titrate based on response and tolerance. Max: 450 mg PO once daily. When discontinuing treatment, doses of 300 mg/day or more should be tapered to 150 mg PO once daily prior to discontinuation.
• Tricyclic antidepressants ^r30c111
  • Amitriptyline ^c112
    • Amitriptyline Hydrochloride Oral tablet; Adolescents: Begin at a low daily dosage, usually at bedtime, and titrate as needed and tolerated. Lower doses are used compared to young adults; 10 mg PO 3 times per day with 20 mg PO at bedtime may be satisfactory in adolescents who do not tolerate higher dosages. When satisfactory improvement has occurred, reduce to the lowest effective dose. Weight-based dosing has been used in clinical trials in adolescents for other indications. TCAs are not drugs of choice for pediatric patients with depression; there is lack of high-quality data to support efficacy and safety.
    • Amitriptyline Hydrochloride Oral tablet; Adults: Initially, 75 mg/day PO, given in divided doses, or, 50 mg to 100 mg PO once daily at bedtime. Hospitalized patients may require 100 mg/day PO initially. Titrate if needed, up to 150 mg/day PO, by increasing the daily dose 25 to 50 mg at weekly intervals, to response and tolerance. Max (hospitalized patients): 300 mg/day PO. Usual maintenance dose: 50 to 100 mg PO per day. In some patients, 40 mg/day PO is sufficient. For maintenance, give as a single dose, preferably at bedtime. Use lowest effective dose. It is appropriate to continue maintenance therapy 3 months or longer to lessen the possibility of relapse.
    • Amitriptyline Hydrochloride Oral tablet; Geriatric: 10 to 25 mg PO at bedtime initially. Titrate as needed and tolerated. Max: 150 mg/day PO, but such doses are not typically tolerated in the geriatric adult. Usual adult maintenance dosage: 50 to 100 mg per day. In some patients, 40 mg/day is sufficient. For maintenance therapy, give as a single dose, preferably at bedtime. Use lowest effective dose. It is appropriate to continue maintenance therapy 3 months or longer to lessen the possibility of relapse.
  • Desipramine ^c113
    • Desipramine Hydrochloride Oral tablet; Adolescents: 25 to 50 mg PO at bedtime initially. May titrate at weekly intervals by 25to 50 mg, depending on response and tolerance. Usual Max: 100 mg/day PO, in single or divided doses. Max (hospitalized patients): 150 mg/day PO. Once at a maintenance dosage, administering the total daily dose at bedtime may minimize daytime sedation and improve compliance. TCAs are not drugs of choice for pediatric patients with depression; there is lack of high-quality data to support efficacy and safety.
    • Desipramine Hydrochloride Oral tablet; Adults: 50 to 75 mg/day PO initially, in single or divided doses. Titrate by 25 to 50 mg at weekly intervals according to response and tolerance. The usual adult dose is 100 mg to 200 mg PO per day, in single or divided doses. Max: 300 mg/day PO. Patients requiring up to 300 mg/day should generally be hospitalized for therapy initiation. Once at a maintenance dosage, administering the total daily dose at bedtime may minimize daytime sedation and improve compliance.
    • Desipramine Hydrochloride Oral tablet; Geriatric: 25 mg PO at bedtime initially. May titrate at weekly intervals by 25 to 50 mg, depending on response and tolerance. Usual max: 100 mg/day PO, in single or divided doses. Max (hospitalized patients): 150 mg/day PO. Once at a maintenance dosage, administering the total daily dose at bedtime may minimize daytime sedation and improve compliance.
  • Imipramine ^c114
    • Imipramine Hydrochloride Oral tablet; Adolescents: Initially, 30 mg to 40 mg/day PO once daily at bedtime to help minimize daytime sedation. If necessary, titrate upward based on response and tolerability. Usual Max: 100 mg/day PO. Use the lowest effective dose that maintains remission. TCAs are not drugs of choice for pediatric patients with depression; there is lack of high-quality data to support efficacy and safety.
    • Imipramine Hydrochloride Oral tablet; Adults: OUTPATIENTS: Initially, 75 mg/day PO; bedtime dosing may reduce daytime sedation. The, titrate to 150 mg/day as a single dose or divided doses based on response and tolerability. Optimal response may take 1 to 3 weeks of treatment at a given dose. Maintenance: 50 to 150 mg/day. Outpatient Max: 200 mg/day PO. HOSPITALIZED ADULTS: Initially, 100 mg/day PO in divided doses, gradually increased to 200 mg/day PO in divided doses as required. If no response after 2 weeks, increase to 250 mg/day to 300 mg/day PO. Hospitalized patient Max: 300 mg/day PO. Use lowest effective dose that maintains remission.
    • Imipramine Hydrochloride Oral tablet; Geriatric Adults: Initially, 30 mg to 40 mg/day PO once daily at bedtime to help minimize daytime sedation. If necessary, titrate to response and tolerability. Usual Max: 100 mg/day. Use the lowest effective dose that maintains remission.
  • Nortriptyline ^c115
    • Nortriptyline Hydrochloride Oral capsule; Adolescents: Initially, 10 mg or 25 mg PO at bedtime.May increase as tolerated to 30 mg to 50 mg per day, given in divided doses or once daily at bedtime. TCAs are not drugs of choice for pediatric patients with depression; the quality of data to support efficacy and safety in adolescents is considered marginal.
    • Nortriptyline Hydrochloride Oral capsule; Adults: Initially, 25 mg to 50 mg PO per day, given in divided doses or at bedtime. May increase as needed and tolerated. Max: 150 mg/day PO.
    • Nortriptyline Hydrochloride Oral capsule; Geriatric Adults: Initially, 10 mg to 25 mg PO at bedtime. May increase as tolerated to 30 mg to 50 mg per day, in divided doses or at bedtime.
• MAOIs ^r37c116
  • Avoid alcohol, tobacco, caffeine, and tyramine-containing foods (eg, aged cheeses, cured meats, fermented cabbage, soy sauce, fava beans) except when taking selegiline at the lowest dosage.
  • Isocarboxazid ^c117
    • Isocarboxazid Oral tablet; Adolescents 16 years and older: In patients receiving contraindicated drugs known to interact with MAOIs, the interacting drug should be discontinued for at least 1 to 2 weeks before initiating isocarboxazid therapy. INITIAL DOSAGE: 10 mg PO twice daily. Carefully assess for drug efficacy and safety to individualize dosage. May increase by 10 mg/day PO every 2 to 4 days, up to 40 mg/day PO by end of first week. May increase further by up to 20 mg/week, if needed and tolerated. Max: 60 mg/day PO, given in 2 to 4 divided doses. Use caution if receiving more than 40 mg/day PO. MAINTENANCE DOSAGE: After maximum clinical response is achieved, reduce the dosage over several weeks to the lowest dosage that maintains effectiveness to limit cumulative MAOI effects and serious dose-related toxicity. Periodically re-evaluate for drug effectiveness and safety.
    • Isocarboxazid Oral tablet; Adults: In patients receiving contraindicated drugs known to interact with MAOIs, the interacting drug should be discontinued for at least 1 to 2 weeks before initiating isocarboxazid therapy. INITIAL DOSAGE: 10 mg PO twice daily. Carefully assess for drug efficacy and safety to individualize dosage. May increase by 10 mg/day PO every 2 to 4 days, up to 40 mg/day PO by end of first week. May increase further by up to 20 mg/week, if needed and tolerated. Max: 60 mg/day PO, given in 2 to 4 divided doses. Use caution if receiving more than 40 mg/day PO. MAINTENANCE DOSAGE: After maximum clinical response is achieved, reduce the dosage over several weeks to the lowest dosage that maintains effectiveness to limit cumulative MAOI effects and serious dose-related toxicity. Periodically re-evaluate for drug effectiveness and safety.
  • Phenelzine ^c118
    • Phenelzine Sulfate Oral tablet; Adults: 15 mg PO 3 times daily; may rapidly increase to 60 mg/day if tolerated. Individualize dosage based on careful observation. For some, an increase up to 90 mg/day may be necessary. Onset of maximum effect is 2 to 6 weeks. After the maximum benefit is achieved, reduce dosage slowly over several weeks to the lowest dose that maintains effectiveness. Maintenance dose may be as low as 15 mg/day PO or 15 mg PO every other day, continued as long as required. NOTE: In patients requiring a contraindicated drug known to interact with MAOIs, phenelzine should be discontinued for at least 2 weeks before initiating the interacting drug.
  • Selegiline ^c119
    • Selegiline Hydrochloride Transdermal patch - 24 hour; Adults: Initially, 6 mg/24 hours transdermally once daily. If clinically indicated, increase by 3 mg/24 hour at intervals of no less than 2 weeks. Effective dose range: 6 to 12 mg/24 hours. Max: 12 mg/24 hours. Inform patients to avoid tyramine-containing foods/beverages/dietary supplements beginning on the first day of selegiline 9 mg or 12 mg/24 hours treatment. Avoid tyramine for 2 weeks after dose reduction (to 6 mg/24 hours) or discontinuation of 9 mg/24 hours or 12 mg/24 hours.
• N-methyl-D-aspartate receptor antagonists ^c120
  • Esketamine nasal spray ^r28r29c121
    • First N-methyl-D-aspartate antagonist to receive FDA approval for major depression.
    • Used as an adjunct to an oral antidepressant for treatment-resistant depression (those who have failed 2 or more standard antidepressant treatments).
    • Only available through a restricted distribution system, under a Risk Evaluation and Mitigation Strategy, owing to risk of serious adverse outcomes resulting from sedation and dissociation, the potential for drug misuse, and suicidal thoughts and behaviors in young adults.
    • Owing to sedation and dissociation risk, patients must be monitored for at least 2 hours after each treatment, followed by a repeat assessment to ensure patient is clinically stable and safe to leave the health care setting. ^r38
    • Esketamine Nasal spray, solution; Adults: INDUCTION PHASE: On day 1, administer 56 mg intranasally. Week 1 through 4: 56 mg or 84 mg twice per week. MAINTENANCE PHASE: Week 5 through 8: 56 mg or 84 mg once weekly. Week 9 and beyond: 56 mg or 84 mg once every 2 weeks or once weekly; use the least frequent dosing needed to maintain remission/response.

Nondrug and supportive care

Music therapy

• Music therapy (provided by a music therapist) has been found to decrease depressive symptoms, improve anxiety associated with major depressive disorder, and improve functioning ^r39c122

Acupuncture ^r40c123

• Small to moderate reduction in the severity of depressive symptoms has been reported

Exercise ^r41c124

• Exercise has been shown to have significant effect in reducing depressive symptoms in patients with major depressive disorder,^r42 especially regular, moderate-level, aerobic exercise

Comorbidities

• Anxiety disorder ^c134
  • Approximately one-half of patients with anxiety disorders have other mood disorders (typically dysthymia or depression) ^r53
• Obsessive-compulsive disorder ^c135
  • Often produces additional depression symptoms
• Substance use disorder (eg, alcohol, opioids, amphetamine, cocaine, cannabis) ^c136
  • Associated with depression and suicide attempts
  • Impulsivity is heightened when under the influence of substances ^r54
• Coronary artery disease ^c137
  • Risk of future cardiac events is 2 to 3 times higher in patients with coronary artery disease and depression when compared to patients without depression ^r55
  • Depression has been shown to be an independent risk factor for mortality in cardiovascular disease, especially in patients with a heart failure diagnosis. ^r56
• Diabetes mellitus ^c138
  • Patients with diabetes and depression experience worse glycemic control and an increased risk of diabetic complications ^r55
• Obesity ^c139
  • Depression-associated low motivation, poor adherence, negative thinking, fatigue, and sleep problems reduce the success of early-treatment weight loss programs ^r57
• Hypertension ^c140
  • People who carry a diagnosis of depression have a higher incidence of hypertension than in the general population ^r58
  • Antidepressants can affect blood pressure and the individual effect can be highly variable with greater increases noted in the elderly, those with higher baseline blood pressure, and using antihypertensive therapy or with kidney disease ^r59
  • Selective serotonin reuptake inhibitors have a lower impact on blood pressure than other antidepressants ^r58
  • Monoamine oxidase inhibitors, tricyclic antidepressants, and serotonin-norepinephrine reuptake inhibitors have a higher chance of increasing blood pressure ^r58r60

Special populations

• Pregnant patients
  • Untreated major depressive disorder in pregnancy poses a risk to the mother and fetus (potential harm from malnutrition, poor prenatal care, substance use disorder, or suicide attempts)
  • Treatment can include psychotherapy and medications determined by the patient's obstetrician and psychiatrist
    • Given the potential harms to the fetus and neonate from certain pharmacologic agents, clinicians are encouraged to consider cognitive behavioral therapy or other evidence-based counseling interventions when managing depression in pregnant or breastfeeding patients ^r1r7
• Older adults
  • Antidepressants pose greater risk for adverse events because of multiple medical comorbidities and drug-drug interactions in case of polypharmacy. ^r61
• Patients diagnosed with dementia
  • High-quality evidence does not support the use of pharmacologic treatment of depression in patients with dementia. ^r61

At-risk populations

• US Preventive Services Task Force recommends screening adults for major depression; the optimum interval for screening is unknown ^{r1c143c144c145c146}
• US Preventive Services Task Force recommends screening adolescents aged 12 to 18 years for major depressive disorder ^r63
• American Academy of Pediatrics guidelines recommends screening adolescent patients aged 12 years and older annually for depression with a formal self-report screening tool ^r64
• US Department of Veterans Affairs recommends screening for major depression annually ^{r14c147c148c149c150}
• American College of Obstetricians and Gynecologists recommends patients be screened for depression and anxiety symptoms at least once during the perinatal period, using a standardized, validated tool; screening for postpartum depression and anxiety is also recommended, using a validated instrument ^r65

Screening tests

• Standardized depression inventory tests include Beck Depression Inventory, Major Depression Inventory, Hamilton Depression Rating Scale, and Patient Health Questionnaire-9 ^{r1r2r3r14c151c152c153c154}