(See also Overview of Mood Disorders Overview of Mood Disorders Mood disorders are emotional disturbances consisting of prolonged periods of excessive sadness, excessive joyousness, or both. Mood disorders can occur in children and adolescents (see Depressive... read more .)
The term depression is often used to refer to any of several depressive disorders. Some are classified in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) by specific symptoms:
Major depressive disorder Major depression (unipolar disorder) Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more (often called major depression)
Others are classified by etiology:
Depressive disorder due to another medical condition
Substance/medication-induced depressive disorder
Depressive disorders occur at any age but typically develop during the mid teens, 20s, or 30s (see also Depressive Disorders in Children and Adolescents Depressive Disorders in Children and Adolescents Depressive disorders are characterized by sadness or irritability that is severe or persistent enough to interfere with functioning or cause considerable distress. Diagnosis is by history and... read more ). In primary care settings, as many as 30% of patients report depressive symptoms, but < 10% have major depression.
Demoralization and grief
The term depression is often used to describe the low or discouraged mood that results from disappointments (eg, financial calamity, natural disaster, serious illness) or losses (eg, death of a loved one). However, better terms for such moods are demoralization and grief.
The negative feelings of demoralization and grief, unlike those of depression, do the following:
Occur in waves that tend to be tied to thoughts or reminders of the inciting event
Resolve when circumstances or events improve
May be interspersed with periods of positive emotion and humor
Are not accompanied by pervasive feelings of worthlessness and self-loathing
The low mood usually lasts days rather than weeks or months, and suicidal thoughts and prolonged loss of function are much less likely.
However, events and stressors that cause demoralization and grief can also precipitate a major depressive episode Major depression (unipolar disorder) Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more , particularly in vulnerable people (eg, those with a past history or family history of major depression). In a small but substantial number of patients, grief may become persistent and disabling. This condition is termed prolonged grief disorder Prolonged grief disorder Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more and may require specifically targeted treatment.
Etiology of Depressive Disorders
Exact cause of depressive disorders is unknown, but genetic and environmental factors contribute.
Heredity accounts for about half of the etiology (less so in late-onset depression). Thus, depression is more common among 1st-degree relatives of depressed patients, and concordance between identical twins is high. Also, genetic factors probably influence the development of depressive responses to adverse events.
Other theories focus on changes in neurotransmitter levels, including abnormal regulation of cholinergic, catecholaminergic (noradrenergic or dopaminergic), glutamatergic, and serotonergic (5-hydroxytryptamine) neurotransmission (1 Etiology reference Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more ). Neuroendocrine dysregulation may be a factor, with particular emphasis on 3 axes: hypothalamic-pituitary-adrenal, hypothalamic-pituitary-thyroid, and hypothalamic-pituitary-growth hormone.
Psychosocial factors also seem to be involved. Major life stresses, especially separations and losses, commonly precede episodes of major depression; however, such events do not usually cause lasting, severe depression except in people predisposed to a mood disorder.
People who have had an episode of major depression are at higher risk of subsequent episodes. People who are less resilient and/or who have anxious tendencies may be more likely to develop a depressive disorder. Such people often do not develop the social skills to adjust to life pressures. The presence of other mental disorders increases risks for major depressive disorder.
Women are at higher risk, but no theory explains why. Possible factors include the following:
Greater exposure to or heightened response to daily stresses
Higher levels of monoamine oxidase (the enzyme that degrades neurotransmitters considered important for mood)
Higher rates of thyroid dysfunction
Endocrine changes that occur with menstruation and at menopause
In peripartum-onset depression, symptoms develop during pregnancy or within 4 weeks after delivery (postpartum depression Postpartum Depression Postpartum depression is depressive symptoms that last > 2 weeks after delivery and meet criteria for major depression. Postpartum depression occurs in 10 to 15% of women after delivery. Although... read more ); endocrine changes have been implicated, but the specific cause is unknown.
In seasonal affective disorder, symptoms develop in a seasonal pattern, typically during autumn or winter; the disorder tends to occur in climates with long or severe winters.
Depressive symptoms or disorders may accompany various physical disorders, including thyroid disorders Overview of Thyroid Function The thyroid gland, located in the anterior neck just below the cricoid cartilage, consists of 2 lobes connected by an isthmus. Follicular cells in the gland produce the 2 main thyroid hormones... read more , adrenal gland disorders Overview of Adrenal Function The adrenal glands, located on the cephalad portion of each kidney (see figure Adrenal glands), consist of a Cortex Medulla The adrenal cortex and adrenal medulla each have separate endocrine... read more , benign and malignant brain tumors Overview of Intracranial Tumors Intracranial tumors may involve the brain or other structures (eg, cranial nerves, meninges). The tumors usually develop during early or middle adulthood but may develop at any age; they are... read more , stroke Overview of Stroke Strokes are a heterogeneous group of disorders involving sudden, focal interruption of cerebral blood flow that causes neurologic deficit. Strokes can be Ischemic (80%), typically resulting... read more , AIDS Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection results from 1 of 2 similar retroviruses (HIV-1 and HIV-2) that destroy CD4+ lymphocytes and impair cell-mediated immunity, increasing risk of certain... read more , Parkinson disease Parkinson Disease Parkinson disease is a slowly progressive, degenerative disorder characterized by resting tremor, stiffness (rigidity), slow and decreased movement (bradykinesia), and eventually gait and/or... read more , and multiple sclerosis Multiple Sclerosis (MS) Multiple sclerosis (MS) is characterized by disseminated patches of demyelination in the brain and spinal cord. Common symptoms include visual and oculomotor abnormalities, paresthesias, weakness... read more (see table Some Causes of Symptoms of Depression and Mania Some Causes of Symptoms of Depression and Mania* ).
Certain drugs, such as corticosteroids, some beta-blockers, interferon, and reserpine, can also result in depressive disorders. Abuse of some recreational drugs (eg, alcohol Alcohol Toxicity and Withdrawal Alcohol (ethanol) is a central nervous system depressant. Large amounts consumed rapidly can cause respiratory depression, coma, and death. Large amounts chronically consumed damage the liver... read more , amphetamines Amphetamines Amphetamines are sympathomimetic drugs with central nervous system stimulant and euphoriant properties whose toxic adverse effects include delirium, hypertension, seizures, and hyperthermia... read more ) can lead to or accompany depression. Toxic effects or withdrawal of drugs may cause transient depressive symptoms.
1. Ghasemi M, Phillips C, Fahimi A, et al: Mechanisms of action and clinical efficacy of NMDA receptor modulators in mood disorders. Neurosci Biobehav Rev 80:555-572, 2017. doi: 10.1016/j.neubiorev.2017.07.002
Symptoms and Signs of Depressive Disorders
Depression causes cognitive, psychomotor, and other types of dysfunction (eg, poor concentration, fatigue, loss of sexual desire, loss of interest or pleasure in nearly all activities that were previously enjoyed, sleep disturbances), as well as a depressed mood. People with a depressive disorder frequently have thoughts of suicide Suicidal Behavior Suicide is death caused by an intentional act of self-harm that is designed to be lethal. Suicidal behavior encompasses a spectrum of behavior from suicide attempt and preparatory behaviors... read more and may attempt suicide. Other mental symptoms or disorders (eg, anxiety Overview of Anxiety Disorders Everyone periodically experiences fear and anxiety. Fear is an emotional, physical, and behavioral response to an immediately recognizable external threat (eg, an intruder, a car spinning on... read more and panic attacks Panic Attacks and Panic Disorder A panic attack is the sudden onset of a discrete, brief period of intense discomfort, anxiety, or fear accompanied by somatic and/or cognitive symptoms. Panic disorder is occurrence of repeated... read more ) commonly coexist, sometimes complicating diagnosis and treatment.
Patients with all forms of depression are more likely to abuse alcohol or other recreational drugs in an attempt to self-treat sleep disturbances or anxiety symptoms; however, depression is a less common cause of alcoholic use disorder and other substance use disorders than was once thought. Patients are also more likely to become heavy smokers and to neglect their health, increasing the risk of development or progression of other disorders (eg, chronic obstructive pulmonary disease Chronic Obstructive Pulmonary Disease (COPD) Chronic obstructive pulmonary disease (COPD) is airflow limitation caused by an inflammatory response to inhaled toxins, often cigarette smoke. Alpha-1 antitrypsin deficiency and various occupational... read more [COPD]).
Depression may reduce protective immune responses. Depression increases risk of cardiovascular disorders, myocardial infarctions Acute Myocardial Infarction (MI) Acute myocardial infarction is myocardial necrosis resulting from acute obstruction of a coronary artery. Symptoms include chest discomfort with or without dyspnea, nausea, and diaphoresis.... read more (MIs), and stroke Overview of Stroke Strokes are a heterogeneous group of disorders involving sudden, focal interruption of cerebral blood flow that causes neurologic deficit. Strokes can be Ischemic (80%), typically resulting... read more , perhaps because in depression, cytokines and factors that increase blood clotting are elevated and heart rate variability is decreased—all potential risk factors for cardiovascular disorders.
Major depression (unipolar disorder)
Patients may appear miserable, with tearful eyes, furrowed brows, down-turned corners of the mouth, slumped posture, poor eye contact, lack of facial expression, little body movement, and speech changes (eg, soft voice, lack of prosody, use of monosyllabic words). Appearance may be confused with Parkinson disease Parkinson Disease Parkinson disease is a slowly progressive, degenerative disorder characterized by resting tremor, stiffness (rigidity), slow and decreased movement (bradykinesia), and eventually gait and/or... read more . In some patients, depressed mood is so deep that tears dry up; they report that they are unable to experience usual emotions and feel that the world has become colorless and lifeless.
Nutrition may be severely impaired, requiring immediate intervention.
Some depressed patients neglect personal hygiene or even their children, other loved ones, or pets.
For diagnosis of major depression, ≥ 5 of the following must have been present nearly every day during the same 2-week period, and one of them must be depressed mood or loss of interest or pleasure:
Depressed mood most of the day
Markedly diminished interest or pleasure in all or almost all activities for most of the day
Significant (> 5%) weight gain or loss or decreased or increased appetite
Insomnia (often sleep-maintenance insomnia) or hypersomnia
Psychomotor agitation or retardation observed by others (not self-reported)
Fatigue or loss of energy
Feelings of worthlessness or excessive or inappropriate guilt
Diminished ability to think or concentrate or indecisiveness
Recurrent thoughts of death or suicide, a suicide attempt, or a specific plan for committing suicide
Persistent depressive disorder
Depressive symptoms that persist for ≥ 2 years without remission are classified as persistent depressive disorder (PDD), a category that consolidates disorders formerly termed chronic major depressive disorder and dysthymic disorder.
Symptoms typically begin insidiously during adolescence and may persist for many years or decades. The number of symptoms often fluctuates above and below the threshold for major depressive episode.
Affected patients may be habitually gloomy, pessimistic, humorless, passive, lethargic, introverted, hypercritical of self and others, and complaining. Patients with PDD are also more likely to have underlying anxiety disorders Overview of Anxiety Disorders Everyone periodically experiences fear and anxiety. Fear is an emotional, physical, and behavioral response to an immediately recognizable external threat (eg, an intruder, a car spinning on... read more , substance use disorders Substance Use Disorders Substance use disorders are a type of substance-related disorder that involve a pathologic pattern of behaviors in which patients continue to use a substance despite experiencing significant... read more , or personality (ie, borderline personality) disorders Overview of Personality Disorders Personality disorders in general are pervasive, enduring patterns of thinking, perceiving, reacting, and relating that cause significant distress or functional impairment. Personality disorders... read more .
For diagnosis of persistent depressive disorder, patients must have had a depressed mood for most of the day for more days than not for ≥ 2 years plus ≥ 2 of the following:
Poor appetite or overeating
Insomnia or hypersomnia
Low energy or fatigue
Poor concentration or difficulty making decisions
Feelings of hopelessness
Premenstrual dysphoric disorder
Premenstrual dysphoric disorder involves mood and anxiety symptoms that are clearly related to the menstrual cycle, with onset during the premenstrual phase and a symptom-free interval after menstruation. Symptoms must be present during most menstrual cycles during the past year.
Manifestations are similar to those of premenstrual syndrome Premenstrual Syndrome (PMS) Premenstrual syndrome (PMS) is a recurrent luteal-phase disorder characterized by irritability, anxiety, emotional lability, depression, edema, breast pain, and headaches, occurring during the... read more but are more severe, causing clinically significant distress and/or marked impairment of social or occupational functioning. The disorder may begin any time after menarche; it may worsen as menopause approaches but ceases after menopause. Prevalence is estimated at 2 to 6% of menstruating women in a given 12-month interval.
For diagnosis of premenstrual dysphoric disorder, patients must have ≥ 5 symptoms during the week before menstruation. Symptoms must begin to remit within a few days after onset of menses and become minimal or absent in the week after menstruation. Symptoms must include ≥ 1 of the following:
Marked mood swings (eg, suddenly feeling sad or tearful)
Marked irritability or anger or increased interpersonal conflicts
Marked depressed mood, feelings of hopelessness, or self-deprecating thoughts
Marked anxiety, tension, or an on-edge feeling
In addition, ≥ 1 of the following must be present:
Decreased interest in usual activities
Low energy or fatigue
Marked change in appetite, overeating, or specific food cravings
Hypersomnia or insomnia
Feeling overwhelmed or out of control
Physical symptoms such as breast tenderness or swelling, joint or muscle pain, a feeling of being bloated, and weight gain
Prolonged grief disorder
Prolonged grief is persistent sadness following the loss of a loved one. It is distinct from depression in that the sadness relates to the specific loss rather than the more general feelings of failure associated with depression. In contrast to normal grief this condition may be highly disabling and require therapy specifically designed for prolonged grief disorder.
Prolonged grief is considered present when the grief response (typified by persistent longing or yearning and/or preoccupation with the deceased) lasts a year or longer and is persistent, pervasive, and exceeding cultural norms. It also must be accompanied by ≥ 3 of the following for the last month to a degree that causes distress or disability:
Intense emotional pain
Feeling of identity confusion
Avoidance of reminders of the loss
Feelings of numbness
Feelings of meaninglessness
Difficulty engaging in ongoing life
Other depressive disorder
Clusters of symptoms with characteristics of a depressive disorder that do not meet the full criteria for other depressive disorders but that cause clinically significant distress or impairment of functioning are classified as other depressive (specified or unspecified) disorder.
Included are recurrent periods of dysphoria with ≥ 4 other depressive symptoms that last < 2 weeks in people who have never met criteria for another mood disorder (eg, recurrent brief depression) and depressive periods that last longer but that include insufficient symptoms for diagnosis of another depressive disorder.
Major depression and persistent depressive disorder may include one or more specifiers that describe additional manifestations during a depressive episode:
Anxious distress: Patients feel tense and unusually restless; they have difficulty concentrating because they worry or fear that something awful may happen, or they feel that they may lose control of themselves.
Mixed features: Patients also have ≥ 3 manic or hypomanic symptoms (eg, elevated mood, grandiosity, greater talkativeness than usual, flight of ideas, decreased sleep). Patients who have this type of depression are at increased risk of developing bipolar disorder Bipolar Disorders Bipolar disorders are characterized by episodes of mania and depression, which may alternate, although many patients have a predominance of one or the other. Exact cause is unknown, but heredity... read more .
Melancholic: Patients have lost pleasure in nearly all activities or do not respond to usually pleasurable stimuli. They may be despondent and despairing, feel excessive or inappropriate guilt, or have early morning awakenings, marked psychomotor retardation or agitation, and significant anorexia or weight loss.
Atypical: Patients' mood temporarily brightens in response to positive events (eg, a visit from children). They also have ≥ 2 of the following: overreaction to perceived criticism or rejection, feelings of leaden paralysis (a heavy or weighted-down feeling, usually in the extremities), weight gain or increased appetite, and hypersomnia.
Psychotic: Patients have delusions and/or hallucinations. Delusions often involve having committed unpardonable sins or crimes, harboring incurable or shameful disorders, or being persecuted. Hallucinations may be auditory (eg, hearing accusatory or condemning voices) or visual. If only voices are described, careful consideration should be given to whether the voices represent true hallucinations.
Catatonic: Patients have severe psychomotor retardation, engage in excessive purposeless activity, and/or withdraw; some patients grimace and mimic speech (echolalia) or movement (echopraxia).
Peripartum onset: Onset is during pregnancy or in the 4 weeks after delivery. Psychotic features may be present; infanticide is often associated with psychotic episodes involving command hallucinations to kill the infant or delusions that the infant is possessed.
Seasonal pattern: Episodes occur at a particular time of year, most often fall or winter.
Diagnosis of Depressive Disorders
Clinical criteria (DSM-5)
Complete blood count (CBC), electrolytes, and thyroid-stimulating hormone (TSH), vitamin B12, and folate levels to rule out physical disorders that can cause depression
Diagnosis of depressive disorders is based on identification of the symptoms and signs and the clinical criteria described above. Specific closed-ended questions help determine whether patients have the symptoms required by DSM-5 criteria for diagnosis of major depression. To help differentiate depressive disorders from ordinary mood variations, there must be significant distress or impairment in social, occupational, or other important areas of functioning.
Severity is determined by the degree of pain and disability (physical, social, occupational) and by duration of symptoms. A physician should gently but directly ask patients about any thoughts and plans to harm themselves or others, any previous threats of and/or attempts at suicide Suicidal Behavior Suicide is death caused by an intentional act of self-harm that is designed to be lethal. Suicidal behavior encompasses a spectrum of behavior from suicide attempt and preparatory behaviors... read more , and other risk factors. Psychosis and catatonia indicate severe depression. Melancholic features indicate severe or moderate depression. Coexisting physical conditions, substance use disorders Substance Use Disorders Substance use disorders are a type of substance-related disorder that involve a pathologic pattern of behaviors in which patients continue to use a substance despite experiencing significant... read more , and anxiety disorders Overview of Anxiety Disorders Everyone periodically experiences fear and anxiety. Fear is an emotional, physical, and behavioral response to an immediately recognizable external threat (eg, an intruder, a car spinning on... read more may add to severity.
Depressive disorders must be distinguished from demoralization and grief. Other mental disorders (eg, anxiety disorders Overview of Anxiety Disorders Everyone periodically experiences fear and anxiety. Fear is an emotional, physical, and behavioral response to an immediately recognizable external threat (eg, an intruder, a car spinning on... read more ) can mimic or obscure the diagnosis of depression. Sometimes more than one disorder is present. Major depression (unipolar disorder) must be distinguished from bipolar disorder Bipolar Disorders Bipolar disorders are characterized by episodes of mania and depression, which may alternate, although many patients have a predominance of one or the other. Exact cause is unknown, but heredity... read more .
In older patients, depression can manifest as dementia of depression (formerly called pseudodementia), which causes many of the symptoms and signs of dementia Dementia Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is... read more such as psychomotor retardation and decreased concentration. However, early dementia may cause depression. In general, when the diagnosis is uncertain, treatment of a depressive disorder should be tried.
Differentiating chronic depressive disorders, such as dysthymia, from substance use disorders Substance Use Disorders Substance use disorders are a type of substance-related disorder that involve a pathologic pattern of behaviors in which patients continue to use a substance despite experiencing significant... read more may be difficult, particularly because they can coexist and may contribute to each other.
Physical disorders must also be excluded as a cause of depressive symptoms. Hypothyroidism Hypothyroidism Hypothyroidism is thyroid hormone deficiency. It is diagnosed by clinical features such as a typical facial appearance, hoarse slow speech, and dry skin and by low levels of thyroid hormones... read more often causes symptoms of depression and is common, particularly among older patients. Parkinson disease Parkinson Disease Parkinson disease is a slowly progressive, degenerative disorder characterized by resting tremor, stiffness (rigidity), slow and decreased movement (bradykinesia), and eventually gait and/or... read more , in particular, may manifest with symptoms that mimic depression (eg, loss of energy, lack of expression, paucity of movement). A thorough neurologic examination Introduction to the Neurologic Examination The neurologic examination begins with careful observation of the patient entering the examination area and continues during history taking. The patient should be assisted as little as possible... read more is needed to exclude this disorder.
Several brief questionnaires are available for screening for depression. They help elicit some depressive symptoms but cannot be used alone for diagnosis. However, many of these tools are useful in identifying at-risk people who need more detailed evaluation. Some of the more widely used screening tools include the Patient Health Questionnaire-9 (PHQ-9) and the Beck Depression Inventory (BDI).
No laboratory findings are pathognomonic for depressive disorders. However, laboratory testing is necessary to exclude physical conditions that can cause depression (see table Some Causes of Depression Some Causes of Symptoms of Depression and Mania* ). Tests include complete blood count, thyroid-stimulating hormone levels, and routine electrolyte, vitamin B12, and folate levels and, in older men, testosterone levels. Testing for illicit drug use is sometimes appropriate.
Treatment of Depressive Disorders
(See also Drug Treatment of Depression Drug Treatment of Depression Several drug classes and drugs can be used to treat depression: Selective serotonin reuptake inhibitors (SSRIs) Serotonin modulators (5-HT2 blockers) Serotonin-<span class="disableDrug"... read more .)
Symptoms may remit spontaneously, particularly when they are mild or of short duration. Mild depression may be treated with general support and psychotherapy. Moderate to severe depression is treated with drugs, psychotherapy, or both and sometimes electroconvulsive therapy Electroconvulsive therapy (ECT) Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more . Some patients require a combination of drugs. Improvement may not be apparent until after 1 to 4 weeks of drug treatment.
Depression, especially in patients who have had > 1 episode, is likely to recur; therefore, severe cases often warrant long-term maintenance drug therapy.
Most people with depression are treated as outpatients. Patients with significant suicidal ideation, particularly when family support is lacking, require hospitalization, as do those with psychotic symptoms or physical debilitation.
In patients with substance use disorders Substance Use Disorders Substance use disorders are a type of substance-related disorder that involve a pathologic pattern of behaviors in which patients continue to use a substance despite experiencing significant... read more , depressive symptoms often resolve within a few months of stopping substance use. Antidepressant treatment is much less likely to be effective while substance use continues.
If a physical disorder or drug toxicity could be the cause, treatment is directed first at the underlying disorder. However, if the diagnosis is in doubt or if symptoms are disabling or include suicidal ideation or hopelessness, a therapeutic trial with an antidepressant or a mood-stabilizing drug may help.
Prolonged grief disorder may benefit from psychotherapy specifically tailored to this disorder.
Until definite improvement begins, a physician may need to see patients weekly or biweekly to provide support and education and to monitor progress. Telephone calls may supplement office visits.
Patients and loved ones may be worried or embarrassed about the idea of having a mental disorder. The physician can help by explaining that depression is a serious medical disorder caused by biologic disturbances and requires specific treatment and that the prognosis with treatment is good. Patients and loved ones should be reassured that depression does not reflect a character flaw (eg, laziness, weakness). Telling patients that the path to recovery often fluctuates helps them put feelings of hopelessness in perspective and improves adherence.
Encouraging patients to gradually increase simple activities (eg, taking walks, exercising regularly) and social interactions must be balanced with acknowledging their desire to avoid activities. The physician can suggest that patients avoid self-blame and explain that dark thoughts are part of the disorder and will go away.
Numerous controlled trials have shown that psychotherapy, particularly cognitive-behavioral therapy and interpersonal therapy, is effective in patients with major depressive disorder, both to treat acute symptoms and to decrease the likelihood of relapse. Patients with mild depression tend to have better outcomes than those with more severe depression, but the magnitude of improvement is greater in those with more severe depression.
Drug therapy for depression
Several drug classes and drugs can be used to treat depression:
Choice of drug Drug Choice and Administration of Antidepressants Several drug classes and drugs can be used to treat depression: Selective serotonin reuptake inhibitors (SSRIs) Serotonin modulators (5-HT2 blockers) Serotonin-<span class="disableDrug"... read more may be guided by past response to a specific antidepressant. Otherwise, SSRIs are often the initial drugs of choice. Although the different SSRIs are equally effective for typical cases, certain properties of the drugs make them more or less appropriate for certain patients (see table Antidepressants ).
Electroconvulsive therapy (ECT)
ECT involves the electrical induction of a seizure under controlled conditions. Its mechanism of action is uncertain but the production of seizure activity appears to be integral to its antidepressant effects. Modern ECT, delivered under heavy sedation/general anesthesia, is typically well tolerated but confusion and memory impairment may occur acutely. Much of this improves and is resolved by 6 months following a course of ECT, but retrograde amnesia may persist for the long term. This is particularly so for memories from the several months preceding ECT. Patients with baseline cognitive deficits, those receiving bilateral treatments, older patients, and patients receiving lithium are at higher risk for memory impairment and confusion.
The following are often treated with ECT if drugs are ineffective:
Severe suicidal depression
Depression with agitation or psychomotor retardation
Depression during pregnancy
Patients who have stopped eating may need ECT to prevent death. ECT is particularly effective for psychotic depression.
Response to 6 to 10 ECT treatments is usually dramatic and may be lifesaving. Relapse after ECT is common, and drug therapy is often maintained after ECT is stopped.
Phototherapy is best known for its effects on seasonal depression but appears to be equally effective for nonseasonal depression.
Treatment can be provided at home with a special light unit that provides 2500 to 10,000 lux at a distance of 30 to 60 cm that patients look at for 30 to 60 minutes/day (longer with a less intense light source).
In patients who go to sleep late at night and rise late in the morning, phototherapy is most effective in the morning, sometimes supplemented with 5 to 10 minutes of exposure between 3 PM and 7 PM. For patients who go to sleep and rise early, phototherapy is most effective between 3 PM and 7 PM.
Psychostimulants (eg, dextroamphetamine, methylphenidate) are sometimes used, often with antidepressants. A number of controlled trials support their use in depressive disorders (1 Treatment references Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more ).
Medicinal herbs are used by some patients. St. John’s wort St. John’s Wort The flowers of St. John’s wort (Hypericum perforatum) (SJW) contain its biologically active ingredients, hypericin and hyperforin. SJW may increase central nervous system serotonin and... read more may be effective for mild depression, although data are contradictory. St. John’s wort may interact with other antidepressants and other drugs. Some placebo-controlled studies of omega-3 supplementation, used as augmentation or as monotherapy, have suggested that eicosapentaenoic acid 1 to 2 g once a day has useful antidepressant effects.
Vagus nerve stimulation involves intermittently stimulating the vagus nerve via an implanted pulse generator. It may be useful for depression refractory to other treatments but usually takes 3 to 6 months to be effective.
The use of repetitive transcranial magnetic stimulation (rTMS) for the acute treatment of major depressive disorder has substantial support from controlled trials. Low-frequency rTMS may be applied to the right dorsolateral prefrontal cortex (DLPC), and high-frequency rTMS can be applied to the left DLPC. The most common adverse effects are headaches and scalp discomfort; both occur more often when high-frequency rather than low-frequency rTMS is used.
Deep brain stimulation using implanted electrodes that target the subgenual cingulate or the anterior ventral internal capsule/ventral striatum has had promising results in uncontrolled case series (2 Treatment references Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more ). Controlled trials are underway.
Support groups (eg, the Depression and Bipolar Support Alliance [DBSA] ) can help patients by providing a forum to share their common experiences and feelings.
1. McIntyre RS, Lee y, Zhou AJ, et al: The efficacy of psychostimulants in major depressive episodes: A systematic review and meta-analysis. J Clin Pscyhopharmacol 37 (4):412-418, 2017. doi: 10.1097/JCP.0000000000000723
2. Bergfeld IO, Mantione M, Hoogendoorn MLC, et al: Deep brain stimulation of the ventral anterior limb of the internal capsule for treatment-resistant depression: A randomized clinical trial. JAMA Psychiatry 73 (5):456-64, 2016. doi: 10.1001/jamapsychiatry.2016.0152
Depression is a common disorder that involves depressed mood and/or near-complete loss of interest or pleasure in activities that were previously enjoyed; somatic (eg, weight change, sleep disturbance) and cognitive manifestations (eg, difficulty concentrating) are common.
Depression may markedly impair the ability to function at work and to interact socially; risk of suicide is significant.
Sometimes depressive symptoms are caused by physical disorders (eg, thyroid or adrenal gland disorders, benign or malignant brain tumors, stroke, AIDS, Parkinson disease, multiple sclerosis) or use of certain drugs (eg, corticosteroids, some beta-blockers, interferon, some recreational drugs).
Diagnosis is based on clinical criteria; physical disorders must be ruled out by clinical evaluation and selected testing (eg, CBC; electrolyte, TSH, B12 and folate levels).
Treatment involves psychotherapy and usually drugs; SSRIs are usually tried first, and if they are ineffective, other drugs that affect serotonin, norepinephrine and/or dopamine may be tried.