drug-resistant depression ( TRD ) or treatment-refractory depression is a term used in clinical psychiatry to describe cases of major depressive disorder (MDD) does not respond adequately to programs that match at least two antidepressants. The term was first coined with concept development in 1974. Inadequate responses have traditionally been defined as no response at all. However, many doctors consider an inadequate response if the patient does not achieve full remission of symptoms. Cases of drug-resistant depression where inadequate treatment is sometimes referred to as pseudoresistant. Some of the factors contributing to inadequate treatment are: early treatment discontinuation, inadequate drug dosage, patient disability, misdiagnosis, and psychiatric disorders. Cases of drug-resistant depression can also be referred to by which drug they are taking (eg: SSRI resistance).
Video Treatment-resistant depression
Prevalence
Treatment resistance is relatively common in cases of MDD. Total remission rate after antidepressant treatment was only 50.4%. In cases of depression treated by primary care physicians, 32% of patients responded partially to treatment and 45% did not respond at all.
Maps Treatment-resistant depression
Predictors
psychiatric disorders
Psychiatric disorders of comorbidity are generally undetectable in the treatment of depression. If left untreated, symptoms of this disorder may interfere with evaluation and treatment. Anxiety disorders are one of the most common types of disorders associated with drug-resistant depression. Both disorders generally coexist, and have some similar symptoms. Several studies have shown that patients with MDD and panic disorder are the most likely to not respond to treatment. Substance abuse can also be a predictor of drug-resistant depression. This can cause depressed patients to be disobedient in their treatment, and the effects of certain substances may exacerbate the effects of depression. Other psychiatric disorders that can predict drug-resistant depression include personality disorders, obsessive compulsive disorder, and eating disorders.
comorbid medical disorder
Some patients diagnosed with drug-resistant depression may have undiagnosed health conditions that cause or contribute to their depression. Endocrine disorders such as hypothyroidism, Cushing's disease, and Addison's disease are among the most commonly identified causes of depression. Others include diabetes, coronary artery disease, cancer, HIV, and Parkinson's disease. Another factor is that drugs used to treat comorbid medical disorders may reduce the effectiveness of antidepressants or cause depressive symptoms.
Depression features
Cases of depression in which the patient also displays psychotic symptoms such as delusions or hallucinations are more likely to be resistant to treatment. Another depression picture associated with a poor response to treatment is the longer duration of depressive episodes. Finally, patients with more severe depression and those who commit suicide are more likely to be unresponsive to antidepressant treatment.
Drug treatments
There are three basic categories of drug treatment that can be used when a treatment program is found to be ineffective. One option is to divert the patient to a different drug. Another option is to add drugs to current patient care. This may include combination therapy: a combination of two different antidepressant types, or augmentation therapy: the addition of non-antidepressant drugs that can increase the effectiveness of antidepressants.
Dose increase
Increasing the dose of antidepressants is a common strategy for treating depression that does not respond after adequate duration of treatment. Practitioners using this strategy will usually increase the dose until the patient reports unbearable side effects, symptoms are removed, or the dose is increased to the perceived safe.
Switching antidepressants
Studies have shown wide variability in the effectiveness of antidepressant switching, anywhere from 25-70% of patients responding to different antidepressants. There is support for the effectiveness of switching patients to different SSRIs; 50% of patients are unresponsive after taking one responsive SSRI after taking the second type. Switching patients to different classes of antidepressants may also be effective. Unresponsive patients after taking SSRI may respond to bupropion or MAOI.
Adding drugs
Drugs that have been shown to be effective in cases of drug-resistant depression include lithium, triiodothyronine, benzodiazepine, atypical antipsychotics, and stimulants. Adding lithium may be effective for patients taking several types of antidepressants, I do not appear to be effective in patients taking SSRIs. Triiodothyroxine (T3) is a type of thyroid hormone and has been associated with improvements in mood and depressive symptoms. Benzodiazepines can improve drug-resistant depression by reducing adverse side effects caused by some antidepressants and therefore improving patient compliance. Since the inclusion of olanzapine into psychopharmacology, many psychiatrists have added low doses of olanzapine to antidepressants and other atipiprazole and quipiapine antipsychotics. In particular, the combination of olanzapine and fluoxetine appears to be effective.
It has shown promise in treating refractory depression but it comes with serious side effects. Stimulants such as amphetamines and methylphenidate have also been tested with positive results but have high potential for abuse. However, stimulants have been shown to be effective for depression without abstinence combined with a lack of an addictive personality trait or heart problems.
Ketamine has been tested as a fast-acting antidepressant for drug-resistant depression in bipolar disorder, and major depressive disorder.
Other care options
Electroconvulsive Therapy
Electroconvulsive therapy is generally regarded only as a treatment option in cases of drug-resistant severe depression. This is used when drugs repeatedly fail to improve symptoms, and usually when the patient's symptoms are so severe that they are hospitalized. Electroconvulsive therapy has been found to reduce suicidal thoughts and relieve depressive symptoms. This is associated with an increase in glial cells derived from neurotrophic factors.
Vagus nerve stimulation
Vagal nerve stimulation is a more invasive procedure than electroconvulsive therapy, but has proven to be well tolerated. During the procedure, surgically stimulating electrodes are attached to the vagus nerve; this allows continuous stimulation after implantation. Like electroconvulsive therapy, it is usually used only in cases of severe treatment depression that is unresponsive to treatment.
Psychotherapy
There is little evidence of the effectiveness of psychotherapy in cases of drug-resistant depression. However, a review of the literature suggests that it may be an effective treatment option. Psychotherapy may be effective in this case as it may help relieve stress that may contribute to depressive symptoms.
rTMS
RTM (Recurrent Transcranial Magnetic Stimulation) has gradually become recognized as a valuable therapy option in drug-resistant depression. A number of randomized placebo-controlled trials have compared real versus false rtms. These trials have consistently demonstrated the efficacy of this treatment for severe depression. There are also a number of RCT meta-analyzes that confirm the efficacy of rTMS in drug-resistant major depression, as well as naturalistic studies demonstrating their effectiveness in "real-world" clinical settings.
dTMS
dTMS (In Transcranial Magnetic Stimulation) is a continuation of the same idea as RTM, but in the hope that deeper stimulation of the subcortical area of ââthe brain will increase the effect. Systematic review and assessment of health technology 2015 find less evidence to recommend the above method of ECT or RTM because so little research has been published.
Results
Treatment-resistant depression is associated with more recurrent events than medication-responsive depression. One study showed that as many as 80% of patients who needed more than one treatment recurred within a year. Drug-resistant depression is also associated with a lower long-term quality of life.
References
Source of the article : Wikipedia