Treatment-resistant depression

Last updated
Treatment-resistant depression
Other namesTreatment-refractory depression
Specialty Psychiatry
Symptoms Depressive mood, anhedonia, low energy
Complications Self-harm, suicide

Treatment-resistant depression (TRD) is a term used in psychiatry to describe people with major depressive disorder (MDD) who do not respond adequately to a course of appropriate antidepressant medication within a certain time. [1] Definitions of treatment-resistant depression vary, and they do not include a resistance to psychotherapy. Inadequate response has most commonly been defined as less than 50% reduction in depressive symptoms following treatment with at least one antidepressant medication, although definitions vary widely. [2] Some other factors that may contribute to inadequate treatment are: a history of repeated or severe adverse childhood experiences, early discontinuation of treatment, insufficient dosage of medication, patient noncompliance, misdiagnosis, cognitive impairment, low income and other socio-economic variables, and concurrent medical conditions, including comorbid psychiatric disorders. [2] Cases of treatment-resistant depression may also be referred to by which medications people with treatment-resistant depression are resistant to (e.g.: SSRI-resistant). [3] In treatment-resistant depression adding further treatments such as psychotherapy, lithium, or aripiprazole is weakly supported as of 2019. [4]

Contents

Risk factors

Comorbid psychiatric disorders

Comorbid psychiatric disorders commonly go undetected in the treatment of depression. If left untreated, the symptoms of these disorders can interfere with both evaluation and treatment. Anxiety disorders are one of the most common disorder types associated with treatment-resistant depression. The two disorders commonly co-exist, and have some similar symptoms. Some studies have shown that patients with both MDD and panic disorder are the most likely to be nonresponsive to treatment. Substance abuse may also be a predictor of treatment-resistant depression. It may cause depressed patients to be noncompliant in their treatment, and the effects of certain substances can worsen the effects of depression. Other psychiatric disorders that may predict treatment-resistant depression include attention deficit hyperactivity disorder, [5] personality disorders, obsessive compulsive disorder, and eating disorders. [6]

Comorbid medical disorders

Some people who are diagnosed with treatment-resistant depression may have an underlying undiagnosed health condition that is causing or contributing to their depression. Endocrine disorders like hypothyroidism, Cushing's disease, and Addison's disease are among the most commonly identified as contributing to depression. Others include diabetes, coronary artery disease, cancer, HIV, and Parkinson's disease. Another factor is that medications used to treat comorbid medical disorders may lessen the effectiveness of antidepressants or cause depression symptoms. [6]

Features of depression

People with depression who also display psychotic symptoms such as delusions or hallucinations are more likely to be treatment resistant. Another depressive feature that has been associated with poor response to treatment is longer duration of depressive episodes. [3] Finally, people with more severe depression and those who are suicidal are more likely to be nonresponsive to antidepressant treatment. [7]

Treatment

There are three basic categories of drug treatment that can be used when a medication course is found to be ineffective. One option is to switch the patient to a different medication. Another option is to add a medication to the patient's current treatment. This can include combination therapy: the combination of two different types of antidepressants, or augmentation therapy: the addition of a non-antidepressant medication that may increase the effectiveness of the antidepressant. [8]

Medication

Antidepressants

Dose increase

Increasing the dosage of an antidepressant is a common strategy to treat depression that does not respond after adequate treatment duration. Practitioners who use this strategy will usually increase the dose until the person reports intolerable side effects, symptoms are eliminated, or the dose is increased to the limit of what is considered safe. [9]

Switching antidepressants

Studies have shown a wide variability in the effectiveness of switching antidepressants, with anywhere from 25 to 70% of people responding to a different antidepressant. [10] There is support for the effectiveness of switching people to a different SSRI; 50% of people that were non-responsive after taking one SSRI were responsive after taking a second type. Switching people with treatment-resistant depression to a different class of antidepressants may also be effective. People who are non-responsive after taking an SSRI may respond to moclobemide or tricyclic antidepressants, bupropion or an MAOI. [9]

Some off label antidepressants are low dose ketamine and highly serotonergic catecholamines (including very controlled use of MDMA in the treatment of PTSD and crippling depression/anxiety).[ citation needed ] For lethargic syndromes, dysthymia, or caffeine-resistant amotivation, a dopaminergic stimulant such as methylphenidate, or even dextroamphetamine or methamphetamine can be helpful.[ citation needed ]

Primarily dopaminergic or norepinephrine releasing stimulants, in low doses, have been used especially in the past, or in conjunction with a multidisciplinary therapy approach, although more targeted and "mild" agents, including modafinil and atomoxetine are considered first line[ by whom? ] for both childhood and adult lethargy and inattention disorders, due to their virtually nonexistent abuse potential (limited to one or two cases per 10 000), and higher selectivity, safety, and thus slightly broader therapeutic index. When depression is related or co-morbid to an inattention disorder, often ADHD, then both can be carefully managed with the same first line stimulant medication, typically both methylphenidate and lisdexamfetamine. [11]

Other medications

Medications that have been shown to be effective in people with treatment-resistant depression include lithium, liothyronine, benzodiazepines, atypical antipsychotics, and stimulants. Adding lithium may be effective for people taking some types of antidepressants; it does not appear to be effective in patients taking SSRIs. Liothyronine (synthetic T3) is a type of thyroid hormone and has been associated with improvement in mood and depression symptoms. Benzodiazepines may improve treatment-resistant depression by decreasing the adverse side effects caused by some antidepressants and therefore increasing patient compliance. [12]

Since the entry of olanzapine into psychopharmacology, many[ quantify ] psychiatrists have been adding low dose olanzapine to antidepressants and other atypical antipsychotics such as aripiprazole and quetiapine. Eli Lilly, the company that sells both olanzapine and fluoxetine individually, has also released a combination formulation which contains olanzapine and fluoxetine in a single capsule. Some low to moderate quality evidence points to success in the short term (8–12 weeks) using mianserin (or antipsychotics cariprazine, olanzapine, quetiapine or ziprasidone) to augment antidepressant medications. [13] These have shown promise in treating refractory depression but come with serious side effects. [14] Stimulants such as amphetamines and methylphenidate have also been tested with positive results but have potential for abuse. However, stimulants have been shown to be effective for the unyielding depressed combined lacking addictive personality traits or heart problems. [15] [16] [17]

Ketamine has been tested as a rapid-acting antidepressant [18] for treatment-resistant depression in bipolar disorder, and major depressive disorder. [19] Spravato, a nasal spray form of esketamine, was approved by the FDA in 2019 for use in treatment-resistant depression when combined with an oral antidepressant. [20] [21]

Research

A 2016 placebo randomized controlled trial evaluated the rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression with positive outcome. [22] [23]

Physical psychiatric treatments

Electroconvulsive therapy

Electroconvulsive therapy is generally only considered as a treatment option in severe cases of treatment-resistant depression. It is used when medication has repeatedly failed to improve symptoms, and usually when the patient's symptoms are so severe that they have been hospitalized. Electroconvulsive therapy has been found to reduce thoughts of suicide and relieve depressive symptoms. [24] It is associated with an increase in glial cell line derived neurotrophic factor. [25]

rTMS

rTMS (repetitive transcranial magnetic stimulation) is gradually becoming recognised as a valuable therapeutic option in treatment-resistant depression. A number of randomised placebo-controlled trials have compared real versus sham rTMS. These trials have consistently demonstrated the efficacy of this treatment against major depression. There have also been a number of meta-analyses of RCTs [26] confirming the efficacy of rTMS in treatment-resistant major depression, as well as naturalistic studies showing its effectiveness in "real world" clinical settings. [27] [28]

dTMS

dTMS (deep transcranial magnetic stimulation) is a continuation of the same idea as rTMS, but with the hope that deeper stimulation of subcortical areas of the brain leads to increased effect. [29] A 2015 systematic review and health technology assessment found lacking evidence in order to recommend the method over either ECT or rTMS because so few studies had been published. [29]

Vagus Nerve Stimulation

Vagus nerve stimulation has also been used for treatment-resistant depression. [30]

Deep Brain Stimulation

Deep brain stimulation has been used in a small number of clinical trials to treat people with severe treatment-resistant depression. [31]

Magnetic seizure therapy

Magnetic seizure therapy is currently being investigated for treating refractory depression.

Transcranial direct-current stimulation

Transcranial direct-current stimulation is a form of neuromodulation that uses constant, low direct current delivered via electrodes on the head.

Psychotherapy

There is sparse evidence on the effectiveness of psychotherapy in cases of treatment-resistant depression. [7] However, a review of the literature suggests that it may be an effective treatment option. [32] Psychotherapy may be effective in people with treatment-resistant depression because it can help relieve stress that may contribute to depressive symptoms. [33]

A Cochrane systematic review has shown that psychological therapies (including cognitive behavioural therapy, dialectal behavioural therapy, interpersonal therapy and intensive short-term dynamic psychotherapy) added to usual care (with antidepressants) can be beneficial for depressive symptoms and for response and remission rates over the short term (up to six months) for patients with treatment-resistant depression. Medium‐ (7–12 months) and long‐term (longer than 12 months) effects seem similarly beneficial. Psychological therapies added to usual care (antidepressants) seem as acceptable as usual care alone. [34]

Outcomes

Treatment-resistant depression is associated with more instances of relapse than depression that is responsive to treatment. One study showed that as many as 80% of people with treatment-resistant depression who needed more than one course of treatment relapsed within a year. Treatment-resistant depression has also been associated with lower long-term quality of life. [35] [ clarification needed ]

Another study saw just 8 of 124 patients in remission after two years of standard depression treatment. [36]

Related Research Articles

<span class="mw-page-title-main">Antidepressant</span> Class of medication used to treat depression and other conditions

Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction.

<span class="mw-page-title-main">Major depressive disorder</span> Mental disorder involving persistent low mood, low self-esteem, and loss of interest

Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Introduced by a group of US clinicians in the mid-1970s, the term was adopted by the American Psychiatric Association for this symptom cluster under mood disorders in the 1980 version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), and has become widely used since.

A psychiatric or psychotropic medication is a psychoactive drug taken to exert an effect on the chemical makeup of the brain and nervous system. Thus, these medications are used to treat mental illnesses. These medications are typically made of synthetic chemical compounds and are usually prescribed in psychiatric settings, potentially involuntarily during commitment. Since the mid-20th century, such medications have been leading treatments for a broad range of mental disorders and have decreased the need for long-term hospitalization, thereby lowering the cost of mental health care. The recidivism or rehospitalization of the mentally ill is at a high rate in many countries, and the reasons for the relapses are under research.

<span class="mw-page-title-main">Transcranial magnetic stimulation</span> Brain stimulation using magnetic fields

Transcranial magnetic stimulation (TMS) is a noninvasive form of brain stimulation in which a changing magnetic field is used to induce an electric current at a specific area of the brain through electromagnetic induction. An electric pulse generator, or stimulator, is connected to a magnetic coil connected to the scalp. The stimulator generates a changing electric current within the coil which creates a varying magnetic field, inducing a current within a region in the brain itself.

Dysthymia, also known as persistent depressive disorder (PDD), is a mental and behavioral disorder, specifically a disorder primarily of mood, consisting of similar cognitive and physical problems as major depressive disorder, but with longer-lasting symptoms. The concept was used by Robert Spitzer as a replacement for the term "depressive personality" in the late 1970s.

Biological psychiatry or biopsychiatry is an approach to psychiatry that aims to understand mental disorder in terms of the biological function of the nervous system. It is interdisciplinary in its approach and draws on sciences such as neuroscience, psychopharmacology, biochemistry, genetics, epigenetics and physiology to investigate the biological bases of behavior and psychopathology. Biopsychiatry is the branch of medicine which deals with the study of the biological function of the nervous system in mental disorders.

Atypical depression is defined in the DSM-IV as depression that shares many of the typical symptoms of major depressive disorder or dysthymia but is characterized by improved mood in response to positive events. In contrast to those with atypical depression, people with melancholic depression generally do not experience an improved mood in response to normally pleasurable events. Atypical depression also often features significant weight gain or an increased appetite, hypersomnia, a heavy sensation in the limbs, and interpersonal rejection sensitivity that results in significant social or occupational impairment.

<span class="mw-page-title-main">Psychotic depression</span> Medical condition

Psychotic depression, also known as depressive psychosis, is a major depressive episode that is accompanied by psychotic symptoms. It can occur in the context of bipolar disorder or major depressive disorder. It can be difficult to distinguish from schizoaffective disorder, a diagnosis that requires the presence of psychotic symptoms for at least two weeks without any mood symptoms present. Unipolar psychotic depression requires that psychotic symptoms occur during severe depressive episodes, although residual psychotic symptoms may also be present in between episodes. Diagnosis using the DSM-5 involves meeting the criteria for a major depressive episode, along with the criteria for "mood-congruent or mood-incongruent psychotic features" specifier.

A major depressive episode (MDE) is a period characterized by symptoms of major depressive disorder. Those affected primarily exhibit a depressive mood for at least two weeks or more, and a loss of interest or pleasure in everyday activities. Other symptoms can include feelings of emptiness, hopelessness, anxiety, worthlessness, guilt, irritability, changes in appetite, difficulties in concentration, difficulties remembering details, making decisions, and thoughts of suicide. Insomnia or hypersomnia and aches, pains, or digestive problems that are resistant to treatment may also be present.

The emphasis of the treatment of bipolar disorder is on effective management of the long-term course of the illness, which can involve treatment of emergent symptoms. Treatment methods include pharmacological and psychological techniques.

<span class="mw-page-title-main">Olanzapine/fluoxetine</span> Antidepressant medication

Olanzapine/fluoxetine is a fixed-dose combination medication containing olanzapine (Zyprexa), an atypical antipsychotic, and fluoxetine (Prozac), a selective serotonin reuptake inhibitor (SSRI). Olanzapine/fluoxetine is primarily used to treat the depressive episodes of bipolar I disorder as well as treatment-resistant depression.

<span class="mw-page-title-main">Esketamine</span> Medication

Esketamine, sold under the brand names Spravato and Ketanest among others, is the S(+) enantiomer of ketamine. It is a dissociative hallucinogen drug used as a general anesthetic and as an antidepressant for treatment of depression. It is sold under the Esketamine is the active enantiomer of ketamine in terms of NMDA receptor antagonism and is more potent than racemic ketamine.

Endogenous depression(melancholia) is an atypical subclass of major depressive disorder. It could be caused by genetic and biological factors. Endogenous depression occurs due to the presence of an internal stressor instead of an external stressor. Endogenous depression includes patients with treatment-resistant, non-psychotic, major depressive disorder, characterized by abnormal behavior of the endogenous opioid system but not the monoaminergic system. Symptoms vary in severity, type, and frequency and can be attributed to cognitive, social, biological, or environmental factors that result in persistent feelings of sadness and distress. Since symptoms are due to a biological phenomenon, prevalence rates tend to be higher in older adults. Due to this fact, biological-focused treatment plans are often used in therapy to ensure the best prognosis.

Management of depression is the treatment of depression that may involve a number of different therapies: medications, behavior therapy, psychotherapy, and medical devices.

<span class="mw-page-title-main">Depression in childhood and adolescence</span> Pediatric depressive disorders

Major depressive disorder, often simply referred to as depression, is a mental disorder characterized by prolonged unhappiness or irritability. It is accompanied by a constellation of somatic and cognitive signs and symptoms such as fatigue, apathy, sleep problems, loss of appetite, loss of engagement, low self-regard/worthlessness, difficulty concentrating or indecisiveness, or recurrent thoughts of death or suicide.

Late-life depression refers to depression occurring in older adults and has diverse presentations, including as a recurrence of early-onset depression, a new diagnosis of late-onset depression, and a mood disorder resulting from a separate medical condition, substance use, or medication regimen. Research regarding late-life depression often focuses on late-onset depression, which is defined as a major depressive episode occurring for the first time in an older person.

<span class="mw-page-title-main">Melancholic depression</span> Medical condition

Melancholic depression, or depression with melancholic features, is a DSM-IV and DSM-5 specifier of depressive disorders. The specifier is used to distinguish clinically relevant subsets of causes and symptoms that have the potential to influence treatment.

Electroconvulsive therapy (ECT) is a controversial therapy used to treat certain mental illnesses such as major depressive disorder, schizophrenia, depressed bipolar disorder, manic excitement, and catatonia. These disorders are difficult to live with and often very difficult to treat, leaving individuals suffering for long periods of time. In general, ECT is not looked at as a first line approach to treating a mental disorder, but rather a last resort treatment when medications such as antidepressants are not helpful in reducing the clinical manifestations.

Non-invasive cerebellar stimulation is the application of non-invasive neurostimulation techniques on the cerebellum to modify its electrical activity. Techniques such as transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (tDCS) can be used. The cerebellum is a high potential target for neuromodulation of neurological and psychiatric disorders due to the high density of neurons in its superficial layer, its electrical properties, and its participation in numerous closed-loop circuits involved in motor, cognitive, and emotional functions.

Ketamine-assisted psychotherapy(KAP) is the use of prescribed doses of ketamine, the drug, as an adjunct to psychotherapy sessions. KAP shows significant potential in treating mental disorders such as treatment-resistant depression (TRD), anxiety, obsessive–compulsive disorders (OCD), post-traumatic stress disorders (PTSD), and other conditions. It can also be used for those experiencing substance abuse and physical pain. While it is primarily used as a veterinary anaesthetic, ketamine has also been found to have rapid analgesic and hallucinogenic effects, which has sparked interest in its use as an antidepressant. Despite initial trials of its use in the treatment of mental disorders focussing primarily on its antidepressant effects, newer studies are attempting to harness its psychedelic effects to bring about altered states of consciousness, which will augment the adjunct psychotherapy. Ketamine's neuroplasticity-promoting effects strengthen the cognitive restructuring that takes place through traditional psychotherapy, thereby leading to long-lasting behavioural change. KAP offers promising directions for research on new antidepressant alternatives, but is still not sufficiently defined or evaluated as a treatment combination.

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