Antidepressant

Antidepressants are prescribed to treat major depressive disorder (MDD), anxiety disorders, chronic pain, and some addictions. Antidepressants are often used in combination with one another. Proponents of the monoamine hypothesis of depression recommend choosing an antidepressant which impacts the most prominent symptoms. Under this practice, for example, a person with MDD who is also anxious or irritable would be treated with selective serotonin reuptake inhibitors (SSRIs) or norepinephrine reuptake inhibitors, while a person suffering from loss of energy and enjoyment of life would take a norepinephrine–dopamine reuptake inhibitor. Major depressive disorder The UK National Institute for Health and Care Excellence (NICE)'s 2022 guidelines indicate that antidepressants should not be routinely used for the initial treatment of mild depression, "unless that is the person's preference". The guidelines recommended that antidepressant treatment be considered: • For people with a history of moderate or severe depression. • For people with mild depression that has been present for an extended period. • As a first-line treatment for moderate to severe depression. • As a second-line treatment for mild depression that persists after other interventions. The guidelines further note that in most cases, antidepressants should be used in combination with psychosocial interventions and should be continued for at least six months to reduce the risk of relapse and that SSRIs are typically better tolerated than other antidepressants. Reviews of antidepressants generally find that they benefit adults with depression. Sertraline, escitalopram, and duloxetine may also help reduce symptoms. Likewise, a 2022 systematic review and meta-analysis of randomized controlled trials of antidepressants for major depressive disorder in children and adolescents found small improvements in quality of life. Quality of life as an outcome measure is often selectively reported in trials of antidepressants. Anxiety disorders For children and adolescents, fluvoxamine and escitalopram are effective in treating a range of anxiety disorders. Fluoxetine, sertraline, and paroxetine can also help with managing various forms of anxiety in children and adolescents. In relation to this, most of the benefit of antidepressants for anxiety disorders is attributable to placebo responses rather than to the effects of the antidepressants themselves. The efficacy of different antidepressants is similar. Obsessive–compulsive disorder SSRIs are a second-line treatment for adult obsessive–compulsive disorder (OCD) with mild functional impairment, and a first-line treatment for those with moderate or severe impairment. In children, SSRIs are considered as a second-line therapy in those with moderate-to-severe impairment, with close monitoring for psychiatric adverse effects. Sertraline and fluoxetine are effective in treating OCD for children and adolescents. However, it is used as a second-line treatment because it is less well-tolerated than SSRIs. Despite this, it has not shown superiority to fluvoxamine in trials. All SSRIs can be used effectively for OCD. SNRI use may also be attempted, though no SNRIs have been approved for the treatment of OCD. Despite these treatment options, many patients remain symptomatic after initiating the medication, and less than half achieve remission. Placebo responses are a large component of the benefit of antidepressants in the treatment of depression and anxiety. A 2019 meta-analysis found placebo improvement effect sizes (SMD) of about 1.2 for depression, 1.0 for anxiety disorders, and 0.6 for OCD with antidepressants. Panic disorder Panic disorder is treated relatively well with medications compared to other disorders. Several classes of antidepressants have shown efficacy for this disorder, with SSRIs and SNRIs used first-line. Paroxetine, sertraline, and fluoxetine are FDA-approved for panic disorder, while fluvoxamine, escitalopram, and citalopram are also considered effective for them. SNRI venlafaxine is also approved for this condition. Unlike social anxiety and PTSD, some TCAs antidepressants, like clomipramine and imipramine, have shown efficacy for panic disorder. Moreover, the MAOI phenelzine is also considered useful. Panic disorder has many drugs for its treatment. However, the starting dose must be lower than the one used for major depressive disorder because people have reported an increase in anxiety as a result of starting the medication. In conclusion, while panic disorder's treatment options seem acceptable and useful for this condition, many people are still symptomatic after treatment with residual symptoms. Eating disorders Antidepressants are recommended as an alternative or additional first step to self-help programs in the treatment of bulimia nervosa. SSRIs (fluoxetine in particular) are preferred over other antidepressants due to their acceptability, tolerability, and superior reduction of symptoms in short-term trials. Long-term efficacy remains poorly characterized. Bupropion is not recommended for the treatment of eating disorders, due to an increased risk of seizure. Similar recommendations apply to binge eating disorder. Clinical trials have generated mostly negative results for the use of SSRIs in the treatment of anorexia nervosa. Treatment guidelines from the National Institute of Health and Care Excellence (NICE) Antidepressants including amitriptyline, duloxetine, milnacipran, moclobemide, and pirlindole are recommended by the European League Against Rheumatism (EULAR) for the treatment of fibromyalgia based on "limited evidence". Neuropathic pain A 2014 meta-analysis from the Cochrane Collaboration found the antidepressant duloxetine to be effective for the treatment of pain resulting from diabetic neuropathy. The same group reviewed data for amitriptyline in the treatment of neuropathic pain and found limited useful randomized clinical trial data. They concluded that the long history of successful use in the community for the treatment of fibromyalgia and neuropathic pain justified its continued use. The group was concerned about the potential overestimation of the amount of pain relief provided by amitriptyline, and highlighted that only a small number of people will experience significant pain relief by taking this medication. Bupropion is used to help people stop smoking. Antidepressants are also used to control some symptoms of narcolepsy. Antidepressants may be used to relieve pain in people with active rheumatoid arthritis. However, further research is required. Antidepressants have been shown to be superior to placebo in treating depression in individuals with physical illness, although reporting bias may have exaggerated this finding. Antidepressants have been shown to improve some parts of cognitive functioning for depressed users, such as memory, attention, and processing speed. Certain antidepressants acting as serotonin 5-HT2A receptor antagonists, such as trazodone and mirtazapine, have been used as hallucinogen antidotes or "trip killers" to block the effects of serotonergic psychedelics like psilocybin and lysergic acid diethylamide (LSD). Limitations and strategies Among individuals treated with a given antidepressant, between 30% and 50% do not show a response. Approximately one-third of people achieve a full remission, one-third experience a response, and one-third are non-responders. Partial remission is characterized by the presence of poorly defined residual symptoms. These symptoms typically include depressed mood, anxiety, sleep disturbance, fatigue, and diminished interest or pleasure. It is currently unclear which factors predict partial remission. However, it is clear that residual symptoms are powerful predictors of relapse, with relapse rates three to six times higher in people with residual symptoms than in those, who experience full remission. In addition, antidepressant drugs tend to lose efficacy throughout long-term maintenance therapy. According to data from the Centers for Disease Control and Prevention, less than one-third of Americans taking one antidepressant medication have seen a mental health professional in the previous year. Several strategies are used in clinical practice to try to overcome these limits and variations. They include switching medication, augmentation, and combination. There is controversy amongst researchers regarding the efficacy and risk-benefit ratio of antidepressants. Although antidepressants consistently out-perform a placebo in meta-analyses, the difference is modest and it is not clear that their statistical superiority results in clinical efficacy. The aggregate effect of antidepressants typically results in changes below the threshold of clinical significance on depression rating scales. Assessments of antidepressants using alternative, more sensitive scales, such as the MADRS, do not result in marked difference from the HDRS and likewise only find a marginal clinical benefit. Poor and complex clinical trial design might also account for the small effects seen for antidepressants. The randomized controlled trials used to approve drugs are short, and may not capture the full effect of antidepressants. More naturalistic studies, such as STAR*D, have produced results, which suggest that antidepressants may be less effective in clinical practice than in randomized controlled trials. Critics of antidepressants maintain that the superiority of antidepressants over placebo is the result of systemic flaws in clinical trials and the research literature. Although this issue has diminished with time, it remains an obstacle to accurately assessing the efficacy of antidepressants. Misreporting of clinical trial outcomes and of serious adverse events, such as suicide, is common. Critics charge that the widespread use and public acceptance of antidepressants is the result of pharmaceutical advertising, research manipulation, and misinformation. Switching antidepressants The American Psychiatric Association 2000 Practice Guideline advises that where no response is achieved within the following six to eight weeks of treatment with an antidepressant, switch to an antidepressant in the same class, and then to a different class. A 2006 meta-analysis review found wide variation in the findings of prior studies: for people who had failed to respond to an SSRI antidepressant, between 12% and 86% showed a response to a new drug. However, the more antidepressants an individual had previously tried, the less likely they were to benefit from a new antidepressant trial. Augmentation and combination For a partial response, the American Psychiatric Association (APA) guidelines suggest augmentation or adding a drug from a different class. These include lithium and thyroid augmentation, dopamine agonists, sex steroids, NRIs, glucocorticoid-specific agents, or the newer anticonvulsants. A combination strategy involves adding another antidepressant, usually from a different class to affect other mechanisms. Although this may be used in clinical practice, there is little evidence for the relative efficacy or adverse effects of this strategy. Other tests conducted include the use of psychostimulants as an augmentation therapy. Several studies have shown the efficacy of combining modafinil for treatment-resistant people. It has been used to help combat SSRI-associated fatigue. Long-term use and stopping The effects of antidepressants typically do not continue once the course of medication ends. This results in a high rate of relapse. In 2003, a meta-analysis found that 18% of people who had responded to an antidepressant relapsed while still taking it, compared to 41% whose antidepressant was switched for a placebo. A gradual loss of therapeutic benefit occurs in a minority of people during the course of treatment. A strategy involving the use of pharmacotherapy in the treatment of the acute episode, followed by psychotherapy in its residual phase, has been suggested by some studies. For patients who wish to stop their antidepressants, engaging in brief psychological interventions such as Preventive Cognitive Therapy or mindfulness-based cognitive therapy while tapering down has been found to diminish the risk for relapse. ==Adverse effects==

Antidepressants can cause various adverse effects, depending on the individual and the drug in question. Almost any medication involved with serotonin regulation has the potential to cause serotonin toxicity (also known as serotonin syndrome) – an excess of serotonin that can induce mania, restlessness, agitation, emotional lability, insomnia, and confusion as its primary symptoms. Although the condition is serious, it is not particularly common, generally only appearing at high doses or while on other medications. Assuming proper medical intervention has been taken (within about 24 hours) it is rarely fatal. Antidepressants appear to increase the risk of diabetes by about 1.3-fold. MAOIs tend to have pronounced (sometimes fatal) interactions with a wide variety of medications and over-the-counter drugs. If taken with foods that contain very high levels of tyramine (e.g., mature cheese, cured meats, or yeast extracts), they may cause a potentially lethal hypertensive crisis. At lower doses, the person may only experience a headache due to an increase in blood pressure. In response to these adverse effects, a different type of MAOI, the class of reversible inhibitor of monoamine oxidase A (RIMA), has been developed. The primary advantage of RIMAs is that they do not require the person to follow a special diet while being purportedly effective as SSRIs and tricyclics in treating depressive disorders. Tricyclics and SSRI can cause the so-called drug-induced QT prolongation, especially in older adults; this condition can degenerate into a specific type of abnormal heart rhythm called torsades de pointes, which can potentially lead to sudden cardiac arrest. Some antidepressants are also believed to increase thoughts of suicidal ideation. Antidepressants have been associated with an increased risk of dementia in older adults. Researchers have developed a tool that allows people to rate their concern about common side effects of antidepressants. The tool ranks potential treatment options in a visual display that highlights the drugs with side effects of least concern to an individual. Pregnancy SSRI use in pregnancy has been associated with a variety of risks with varying degrees of proof of causation. As depression is independently associated with negative pregnancy outcomes, determining the extent to which observed associations between antidepressant use and specific adverse outcomes reflect a causative relationship has been difficult in some cases. In other cases, the attribution of adverse outcomes to antidepressant exposure seems fairly clear. SSRI use in pregnancy is associated with an increased risk of spontaneous abortion of about 1.7-fold, and is associated with preterm birth and low birth weight. A systematic review of the risk of major birth defects in antidepressant-exposed pregnancies found a small increase (3% to 24%) in the risk of major malformations and a risk of cardiovascular birth defects that did not differ from non-exposed pregnancies. A study of fluoxetine-exposed pregnancies found a 12% increase in the risk of major malformations that did not reach statistical significance. Other studies have found an increased risk of cardiovascular birth defects among depressed mothers not undergoing SSRI treatment, suggesting the possibility of ascertainment bias, e.g. that worried mothers may pursue more aggressive testing of their infants. Another study found no increase in cardiovascular birth defects and a 27% increased risk of major malformations in SSRI exposed pregnancies. and the MAOI should be avoided. A 2013 systematic review and meta-analysis found that antidepressant use during pregnancy was statistically significantly associated with some pregnancy outcomes, such as gestational age and preterm birth, but not with other outcomes. The same review cautioned that because differences between the exposed and unexposed groups were small, it was doubtful whether they were clinically significant. A neonate (infant less than 28 days old) may experience a withdrawal syndrome from abrupt discontinuation of the antidepressant at birth. Antidepressants can be present in varying amounts in breast milk, but their effects on infants are currently unknown. Moreover, SSRIs inhibit nitric oxide synthesis, which plays an important role in setting the vascular tone. Several studies have pointed to an increased risk of prematurity associated with SSRI use, and this association may be due to an increased risk of pre-eclampsia during pregnancy. Antidepressant-induced mania Another possible problem with antidepressants is the chance of antidepressant-induced mania or hypomania in people with or without a diagnosis of bipolar disorder. Many cases of bipolar depression are very similar to those of unipolar depression. Therefore, the person can be misdiagnosed with unipolar depression and be given antidepressants. Studies have shown that antidepressant-induced mania can occur in 20–40% of people with bipolar disorder. For bipolar depression, antidepressants (most frequently SSRIs) can exacerbate or trigger symptoms of hypomania and mania. Bupropion has been associated with a lower risk of mood switch than other antidepressants. Suicide Studies have shown that the use of antidepressants is correlated with an increased risk of suicidal behavior and thinking (suicidality) in those aged under 25 years old. According to the FDA, the heightened risk of suicidality occurs within the first one to two months of treatment. The National Institute for Health and Care Excellence (NICE) places the excess risk in the "early stages of treatment". A meta-analysis suggests that the relationship between antidepressant use and suicidal behavior or thoughts is age-dependent. There is no effect or possibly a mild protective effect among those aged 25 to 64 (OR=0.79). Antidepressant treatment has a protective effect against suicidality among those aged 65 and over (OR=0.37). Sexual dysfunction Sexual side effects are common with SSRIs, such as loss of sexual drive, failure to reach orgasm, and erectile dysfunction. Although usually reversible, these sexual side-effects can, in rare cases, continue after the drug has been completely withdrawn. In a study of 1,022 outpatients, overall sexual dysfunction with all antidepressants averaged 59.1% with SSRI values between 57% and 73%, mirtazapine 24%, nefazodone 8%, amineptine 7%, and moclobemide 4%. Moclobemide, a selective reversible MAO-A inhibitor, does not cause sexual dysfunction and can lead to an improvement in all aspects of sexual function. Biochemical mechanisms suggested as causative include increased serotonin, particularly affecting 5-HT2 and 5-HT3 receptors; decreased dopamine; decreased norepinephrine; blockade of cholinergic and α1adrenergic receptors; inhibition of nitric oxide synthetase; and elevation of prolactin levels. Mirtazapine is reported to have fewer sexual side effects, most likely because it antagonizes 5-HT2 and 5-HT3 receptors and may, in some cases, reverse sexual dysfunction induced by SSRIs by the same mechanism. Bupropion, a weak NDRI and nicotinic antagonist, may be useful in treating reduced libido as a result of SSRI treatment. Emotional blunting Certain antidepressants may cause emotional blunting, characterized by a reduced intensity of both positive and negative emotions as well as symptoms of apathy, indifference, and amotivation. It may be experienced as either beneficial or detrimental depending on the situation. This side effect has been particularly associated with serotonergic antidepressants like SSRIs and SNRIs but may be less with atypical antidepressants like bupropion, agomelatine, and vortioxetine. In addition, it is not associated with the serotonergic psychedelic psilocybin. Higher doses of antidepressants seem to be more likely to produce emotional blunting than lower doses. while others (such as bupropion and venlafaxine) achieve the opposite effect. The antihistaminic properties of certain TCA- and TeCA-class antidepressants have been shown to contribute to the common side effects of increased appetite and weight gain associated with these classes of medication. Bone loss A 2021 nationwide cohort study in South Korea observed a link between SSRI use and bone loss, particularly in recent users. The study also stressed the need of further research to better understand these effects. A 2012 review found that SSRIs along with tricyclic antidepressants were associated with a significant increase in the risk of osteoporotic fractures, peaking in the months after initiation, and moving back towards baseline during the year after treatment was stopped. These effects exhibited a dose–response relationship within SSRIs which varied between different drugs of that class. A 2018 meta-analysis of 11 small studies found a reduction in bone density of the lumbar spine in SSRI users which affected older people the most. Risk of death A 2017 meta-analysis found that antidepressants were associated with a significantly increased risk of death (+33%) and new cardiovascular complications (+14%) in the general population. Conversely, risks were not greater in people with existing cardiovascular disease. The problem usually begins within three days and may last for several months. The condition is generally not serious, though about half of people with symptoms describe them as severe. Some restart antidepressants due to the severity of the symptoms. ==Pharmacology==

Antidepressants act via a large number of different mechanisms of action. This includes serotonin reuptake inhibition (SSRIs, SNRIs, TCAs, vilazodone, vortioxetine), norepinephrine reuptake inhibition (NRIs, SNRIs, TCAs), dopamine reuptake inhibition (bupropion, amineptine, nomifensine), direct modulation of monoamine receptors (vilazodone, vortioxetine, SARIs, agomelatine, TCAs, TeCAs, antipsychotics), monoamine oxidase inhibition (MAOIs), and NMDA receptor antagonism (ketamine, esketamine, dextromethorphan), among others (e.g., brexanolone, tianeptine). This theory states that depression is due to an imbalance, most often a deficiency, of the monoamine neurotransmitters, namely serotonin, norepinephrine, and/or dopamine. In 2022, a major systematic umbrella review by Joanna Moncrieff and colleagues showed that the serotonin theory of depression was not supported by evidence from a wide variety of areas. The authors concluded that there is no association between serotonin and depression, and that there is no evidence that strongly supports the theory that depression is caused by low serotonin activity or concentrations. This is in spite of about 90% of the general public in Western countries believing the theory to be true and many in the field of psychiatry continuing to promote the theory up to recent times. Instead, findings of reserpine and mood are highly mixed, with similar proportions of studies finding that it has no influence on mood, produces depressive effects, or actually has antidepressant effects. In the case of the pharmaceutical industry, this can be attributed to obvious financial incentives, with the theory creating a bias against non-pharmacological treatments for depression. This is supported by meta-analyses of randomized controlled trials of antidepressants for depression, which consistently show that placebo groups in trials improve about 80 to 90% as much as antidepressant groups on average and that antidepressants are only marginally more effective for depression than placebos. Moreover, the small advantage of antidepressants over placebo may simply be a methodological artifact caused by unblinding due to the psychoactive effects and side effects of antidepressants, in turn resulting in amplified placebo effects and apparent antidepressant efficacy. It has been argued by Kirsch that although antidepressants may be used efficaciously for depression as active placebos, they are limited by significant pharmacological side effects and risks, and therefore non-pharmacological therapies, such as psychotherapy and lifestyle changes, which can have similar efficacy to antidepressants but do not have their adverse effects, ought to be preferred as treatments in people with depression. The placebo response, or the improvement in scores in the placebo group in clinical trials, is not only due to the placebo effect, but is also due to other phenomena such as spontaneous remission and regression to the mean. This suggests that antidepressants may be associated with much less genuine treatment benefit, whether due to the placebo effect or to the antidepressant itself, than has been traditionally assumed. However, due to issues like the inverse placebo effect caused by unblinding, psychedelics may actually be no more effective than traditional antidepressants. ==Types==

Selective serotonin reuptake inhibitors ), a selective serotonin reuptake inhibitor Selective serotonin reuptake inhibitors (SSRIs) are believed to increase the extracellular level of the neurotransmitter serotonin by limiting its reabsorption into the presynaptic cell, increasing the level of serotonin in the synaptic cleft available to bind to the postsynaptic receptor. They have varying degrees of selectivity for the other monoamine transporters, with pure SSRIs having only weak affinity for the norepinephrine and dopamine transporters. SSRIs are the most widely prescribed antidepressants in many countries. The efficacy of SSRIs in mild or moderate cases of depression has been disputed. Serotonin–norepinephrine reuptake inhibitors (Effexor), an SNRI Serotonin–norepinephrine reuptake inhibitors (SNRIs) are potent inhibitors of the reuptake of serotonin and norepinephrine. These neurotransmitters are known to play an important role in mood. SNRIs can be contrasted with the more widely used selective serotonin reuptake inhibitors (SSRIs), which act mostly upon serotonin alone. The human serotonin transporter (SERT) and norepinephrine transporter (NET) are membrane proteins that are responsible for the reuptake of serotonin and norepinephrine. Balanced dual inhibition of monoamine reuptake may offer advantages over other antidepressants drugs by treating a wider range of symptoms. SNRIs are sometimes also used to treat anxiety disorders, obsessive–compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), chronic neuropathic pain, and fibromyalgia syndrome (FMS), and for the relief of menopausal symptoms. Serotonin modulators and stimulators Serotonin modulator and stimulators (SMSs), sometimes referred to more simply as "serotonin modulators", are a type of drug with a multimodal action specific to the serotonin neurotransmitter system. To be precise, SMSs simultaneously modulate one or more serotonin receptors and inhibit the reuptake of serotonin. The term was coined in reference to the mechanism of action of the serotonergic antidepressant vortioxetine, which acts as a serotonin reuptake inhibitor (SRI), a partial agonist of the 5-HT1A receptor, and antagonist of the 5-HT3 and 5-HT7 receptors. However, it can also technically be applied to vilazodone, which is an antidepressant as well and acts as an SRI and 5-HT1A receptor partial agonist. An alternative term is serotonin partial agonist/reuptake inhibitor (SPARI), which can be applied only to vilazodone. Serotonin antagonists and reuptake inhibitors Serotonin antagonist and reuptake inhibitors (SARIs) while mainly used as antidepressants are also anxiolytics and hypnotics. They act by antagonizing serotonin receptors such as 5-HT2A and inhibiting the reuptake of serotonin, norepinephrine, and/or dopamine. Additionally, most also act as α1-adrenergic receptor antagonists. The majority of the currently marketed SARIs belong to the phenylpiperazine class of compounds. They include trazodone and nefazodone. Tricyclic antidepressants The majority of the tricyclic antidepressants (TCAs) act primarily as serotonin–norepinephrine reuptake inhibitors (SNRIs) by blocking the serotonin transporter (SERT) and the norepinephrine transporter (NET), respectively, which results in an elevation of the synaptic concentrations of these neurotransmitters, and therefore an enhancement of neurotransmission. Notably, with the sole exception of amineptine, the TCAs have weak affinity for the dopamine transporter (DAT), and therefore have low efficacy as dopamine reuptake inhibitors (DRIs). Tetracyclic antidepressants Tetracyclic antidepressants (TeCAs) are a class of antidepressants that were first introduced in the 1970s. They are named after their chemical structure, which contains four rings of atoms, and are closely related to tricyclic antidepressants (TCAs), which contain three rings of atoms. Monoamine oxidase inhibitors Monoamine oxidase inhibitors (MAOIs) are chemicals that inhibit the activity of the monoamine oxidase enzyme family. They have a long history of use as medications prescribed for the treatment of depression. They are particularly effective in treating atypical depression. They are also used in the treatment of Parkinson's disease and several other disorders. Because of potentially lethal dietary and drug interactions, MAOIs have historically been reserved as a last line of treatment, used only when other classes of antidepressant drugs (for example selective serotonin reuptake inhibitors and tricyclic antidepressants) have failed. MAOIs have been found to be effective in the treatment of panic disorder with agoraphobia, social phobia, atypical depression or mixed anxiety and depression, bulimia, and post-traumatic stress disorder, as well as borderline personality disorder. MAOIs appear to be particularly effective in the management of bipolar depression according to a retrospective-analysis. There are reports of MAOI efficacy in obsessive–compulsive disorder (OCD), trichotillomania, dysmorphophobia, and avoidant personality disorder, but these reports are from uncontrolled case reports. MAOIs can also be used in the treatment of Parkinson's disease by targeting MAO-B in particular (therefore affecting dopaminergic neurons), as well as providing an alternative for migraine prophylaxis. Inhibition of both MAO-A and MAO-B is used in the treatment of clinical depression and anxiety disorders. NMDA receptor antagonists NMDA receptor antagonists like ketamine and esketamine are rapid-acting antidepressants and seem to work via blockade of the ionotropic glutamate NMDA receptor. Other NMDA antagonists may also play a role in treating depression. The combination medication dextromethorphan/bupropion (Auvelity), which contains the NMDA receptor antagonist dextromethorphan, was approved in the United States in 2022 for treating major depressive disorder. Others See the list of antidepressants and management of depression for other drugs that are not specifically characterized. ==Adjuncts==

Adjunct medications are an umbrella category of substances that increase the potency or "enhance" antidepressants. They work by affecting variables very close to the antidepressant, sometimes affecting a completely different mechanism of action. This may be attempted when depression treatments have not been successful in the past. Common types of adjunct medication techniques generally fall into the following categories: • Two or more antidepressants taken together, from either the same or different classes (affecting the same area of the brain, often at a much higher level). • An antipsychotic combined with an antidepressant, particularly atypical antipsychotics such as aripiprazole (Abilify), quetiapine (Seroquel), olanzapine (Zyprexa), and risperidone (Risperdal). It is unknown if undergoing psychological therapy at the same time as taking anti-depressants enhances the anti-depressive effect of the medication. Less common adjuncts Lithium has been used to augment antidepressant therapy in those who have failed to respond to antidepressants alone. Furthermore, Lithium dramatically decreases the suicide risk in recurrent depression. In addition to reducing the risk of suicide, lithium also reduces the risk of death from all causes in people with mood disorders. There is some evidence for the addition of a thyroid hormone, triiodothyronine, in patients with normal thyroid function. Psychopharmacologists have also tried adding a stimulant, in particular, D-amphetamine. However, the use of stimulants in cases of treatment-resistant depression is relatively controversial. A review article published in 2007 found psychostimulants may be effective in treatment-resistant depression with concomitant antidepressant therapy, but a more certain conclusion could not be drawn due to substantial deficiencies in the studies available for consideration, and the somewhat contradictory nature of their results. ==History==

The idea of an antidepressant, if melancholy is thought synonymous with depression, existed at least as early as the 1599 pamphlet A pil to purge melancholie or, A preparative to a pvrgation: or, Topping, copping, and capping: take either or whether: or, Mash them, and squash them, and dash them, and diddle come derrie come daw them, all together... Thomas d'Urfey's Wit and Mirth: Or Pills to Purge Melancholy, the title of a large collection of songs, was published between 1698 and 1720. Before the 1950s, opioids and amphetamines were commonly used as antidepressants. Amphetamine has been described as the first antidepressant. St John's wort fell out of favor in most countries through the 19th and 20th centuries, except in Germany, where Hypericum extracts were eventually licensed, packaged, and prescribed. Small-scale efficacy trials were carried out in the 1970s and 1980s, and attention grew in the 1990s following a meta-analysis. It remains an over-the-counter (OTC) supplement in most countries. Lead contamination associated with its usage has been seen as concerning, as lead levels in women in the United States taking St. John's wort are elevated by about 20% on average. Research continues to investigate its active component hyperforin, and to further understand its mode of action. Isoniazid, iproniazid, and imipramine In 1951, Irving Selikoff and Edward H. Robitzek, working out of Sea View Hospital on Staten Island, began clinical trials on two new anti-tuberculosis agents developed by Hoffman-LaRoche, isoniazid, and iproniazid. Only patients with a poor prognosis were initially treated. Nevertheless, their condition improved dramatically. Selikoff and Robitzek noted "a subtle general stimulation ... the patients exhibited renewed vigor and indeed this occasionally served to introduce disciplinary problems." The promise of a cure for tuberculosis in the Sea View Hospital trials was excitedly discussed in the mainstream press. In 1952, learning of the stimulating side effects of isoniazid, the Cincinnati psychiatrist Max Lurie tried it on his patients. In the following year, he and Harry Salzer reported that isoniazid improved depression in two-thirds of their patients, so they then coined the term antidepressant to refer to its action. A similar incident took place in Paris, where Jean Delay, head of psychiatry at Sainte-Anne Hospital, heard of this effect from his pulmonology colleagues at Cochin Hospital. In 1952 (before Lurie and Salzer), Delay, with the resident Jean-Francois Buisson, reported the positive effect of isoniazid on depressed patients. The mode of antidepressant action of isoniazid is still unclear. It is speculated that its effect is due to the inhibition of diamine oxidase, coupled with a weak inhibition of monoamine oxidase A. Selikoff and Robitzek also experimented with another anti-tuberculosis drug, iproniazid; it showed a greater psychostimulant effect, but more pronounced toxicity. Later, Jackson Smith, Gordon Kamman, George E. Crane, and Frank Ayd, described the psychiatric applications of iproniazid. Ernst Zeller found iproniazid to be a potent monoamine oxidase inhibitor. Nevertheless, iproniazid remained relatively obscure until Nathan S. Kline, the influential head of research at Rockland State Hospital, began to popularize it in the medical and popular press as a "psychic energizer". Roche put a significant marketing effort behind iproniazid. Antidepressants became prescription drugs in the 1950s. It was estimated that no more than fifty to one hundred individuals per million had the kind of depression that these new drugs would treat, and pharmaceutical companies were not enthusiastic about marketing for this small market. Sales through the 1960s remained poor compared to the sales of tranquilizers, which were being marketed for different uses. Imipramine remained in common use and numerous successors were introduced. The use of monoamine oxidase inhibitors (MAOI) increased after the development and introduction of "reversible" forms affecting only the MAO-A subtype of inhibitors, making this drug safer to use. By the 1960s, it was thought that the mode of action of tricyclics was to inhibit norepinephrine reuptake. However, norepinephrine reuptake became associated with stimulating effects. Later tricyclics were thought to affect serotonin as proposed in 1969 by Carlsson and Lindqvist as well as Lapin and Oxenkrug. Second-generation antidepressants Researchers began a process of rational drug design to isolate antihistamine-derived compounds that would selectively target these systems. The first such compound to be patented was zimelidine in 1971, while the first released clinically was indalpine. Fluoxetine was approved for commercial use by the US Food and Drug Administration (FDA) in 1988, becoming the first blockbuster SSRI. Fluoxetine was developed at Eli Lilly and Company in the early 1970s by Bryan Molloy, Klaus Schmiegel, David T. Wong, and others. SSRIs became known as "novel antidepressants" along with other newer drugs such as SNRIs and NRIs with various selective effects. Rapid-acting antidepressants Esketamine (brand name Spravato), the first rapid-acting antidepressant to be approved for clinical treatment of depression, was introduced for this indication in March 2019 in the United States. In 2018, the FDA granted Breakthrough Therapy Designation for psilocybin-assisted therapy for treatment-resistant depression and in 2019, the FDA granted Breakthrough Therapy Designation for psilocybin therapy treating major depressive disorder. Publication bias and aged research A 2018 systematic review published in The Lancet comparing the efficacy of 21 different first and second generation antidepressants found that antidepressant drugs tended to perform better and cause less adverse events when they were novel or experimental treatments compared to when they were evaluated again years later. Unpublished data was also associated with smaller positive effect sizes. However, the review did not find evidence of bias associated with industry funded research. ==Society and culture==

Prescription trends United Kingdom In the UK, figures reported in 2010 indicated that the number of antidepressants prescribed by the National Health Service (NHS) almost doubled over a decade. Further analysis published in 2014 showed that number of antidepressants dispensed annually in the community went up by 25 million in the 14 years between 1998 and 2012, rising from 15 million to 40 million. Nearly 50% of this rise occurred in the four years after the Great Recession, during which time the annual increase in prescriptions rose from 6.7% to 8.5%. These sources also suggest that aside from the recession, other factors that may influence changes in prescribing rates may include: improvements in diagnosis, a reduction of the stigma surrounding mental health, broader prescribing trends, GP characteristics, geographical location, and housing status. Another factor that may contribute to increasing consumption of antidepressants is the fact that these medications now are used for other conditions including social anxiety and post-traumatic stress disorder. Between 2005 and 2017, the number of adolescents (12 to 17 years) in England who were prescribed antidepressants has doubled. On the other hand, antidepressant prescriptions for children aged 5–11 in England decreased between 1999 and 2017. From April 2015, prescriptions increased for both age groups (for people aged 0 to 17) and peaked during the first COVID lockdown in March 2020. According to National Institute for Health and Care Excellence (NICE) guidelines, antidepressants for children and adolescents with depression and obsessive-compulsive disorder (OCD) should be prescribed together with therapy and after being assessed by a child and adolescent psychiatrist. However, between 2006 and 2017, only 1 in 4 of 12–17 year-olds who were prescribed an SSRI by their GP had seen a specialist psychiatrist and 1 in 6 has seen a pediatrician. Half of these prescriptions were for depression and 16% for anxiety, the latter not being licensed for treatment with antidepressants. Among the suggested possible reasons why GPs are not following the guidelines are the difficulties of accessing talking therapies, long waiting lists, and the urgency of treatment. According to some researchers, strict adherence to treatment guidelines would limit access to effective medication for young people with mental health problems. United States In the United States, antidepressants were the most commonly prescribed medication in 2013. , about 16.5% of white people in the United States took antidepressants compared with 5.6% of black people in the United States. United States: The most commonly prescribed antidepressants in the US retail market in 2010 were: Netherlands: In the Netherlands, paroxetine is the most prescribed antidepressant, followed by amitriptyline, citalopram and venlafaxine. Adherence , worldwide, 30% to 60% of people did not follow their practitioner's instructions about taking their antidepressants, and in the US, it appeared that around 50% of people did not take their antidepressants as directed by their practitioner. When people fail to take their antidepressants, there is a greater risk that the drug will not help, that symptoms get worse, that they miss work or are less productive at work, and that the person may be hospitalized. Social science perspective Some academics have highlighted the need to examine the use of antidepressants and other medical treatments in cross-cultural terms, because various cultures prescribe and observe different manifestations, symptoms, meanings, and associations of depression and other medical conditions within their populations. These cross-cultural discrepancies, it has been argued, then have implications on the perceived efficacy and use of antidepressants and other strategies in the treatment of depression in these different cultures. these drugs can interfere with natural neurotransmitter levels in other organisms impacted by indirect exposure. Antidepressants fluoxetine and sertraline have been detected in aquatic organisms residing in effluent-dominated streams. The presence of antidepressants in surface waters and aquatic organisms has caused concern because ecotoxicological effects on aquatic organisms due to fluoxetine exposure have been demonstrated. Coral reef fish have been demonstrated to modulate aggressive behavior through serotonin. Artificially increasing serotonin levels in crustaceans can temporarily reverse social status and turn subordinates into aggressive and territorial dominant males. Exposure to Fluoxetine has been demonstrated to increase serotonergic activity in fish, subsequently reducing aggressive behavior. Perinatal exposure to Fluoxetine at relevant environmental concentrations has been shown to lead to significant modifications of memory processing in 1-month-old cuttlefish. This impairment may disadvantage cuttlefish and decrease their survival. Somewhat less than 10% of orally administered Fluoxetine is excreted from humans unchanged or as glucuronide. ==See also==