A sulfide ion is composed of a lone sulfur atom. Its charge is negative two, giving sulfides this formula: S^2-. Sulfide is a strong base, so solutions of sulfide in water are basic, due to hydrolysis. One well-known ionic compound with a sulfide ion is H_2S. The infamous rotten-egg smell often associated with sulfur originates from this compound. Sodium sulfide nonahydrate is used in the formation of surface functionalized cadmium sulfide quantum dots.

Lysergide (LSD) is a semi-synthetic hallucinogen and is one of the most potent drugs known. Recreational use became popular between the 1960s to 1980s, but is now less common. LSD was first synthesized by Albert Hoffman while working for Sandoz Laboratories in Basel in 1938. Some years later, during a re-evaluation of the compound, he accidentally ingested a small amount and described the first ‘trip’. During the 1950s and 1960s, Sandoz evaluated the drug for therapeutic purposes and marketed it under the name Delysid®. It was used for research into the chemical origins of mental illness. Recreational use started in the 1960s and is associated with the ‘psychedelic period’. LSD possesses a complex pharmacological profile that includes direct activation of serotonin, dopamine and norepinephrine receptors. In addition, one of its chief sites of action is that of compound-specific (“allosteric”) alterations in secondary messengers associated with 5HT2A and 5HT2C receptor activation and changes in gene expression. The hallucinogenic effects of LSD are likely due to agonism at 5HT2A and 5HT2C receptors. LSD is also an agonist at the majority of known serotonin receptors, including 5HT1A, 5HT1B, 5HT1D, 5HT5A, 5HT6 and 5HT7 receptors. During the 1960s, LSD was investigated for a variety of psychiatric indications, including the following: as an aid in treatment of schizophrenia; as a means of creating a "model psychosis"; as a direct antidepressant; and as an adjunct to psychotherapy. LSD is listed in Schedule I of the United Nations 1971 Convention on Psychotropic Substances.

Tezampanel, also known as LY 293558 and NGX-424, is a drug originally developed by Eli Lilly, which is a competitive antagonist of the AMPA and kainate subtypes of the ionotropic glutamate receptor family. Tezampanel was in phase II clinical trial for treatment migraine, but this study was discontinued. Also this drug has several others potential pharmacological actions, one of them is anxiety disorders

Kynurenine is a metabolite of the amino acid L-tryptophan used in the production of niacin. Kynurenine is synthesized by the enzyme tryptophan dioxygenase, which is made primarily but not exclusively in the liver, and indoleamine 2,3-dioxygenase, which is made in many tissues in response to immune activation. Kynurenine and its further breakdown products carry out diverse biological functions, including dilating blood vessels during inflammation and regulating the immune response. Evidence suggests that increased kynurenine production may precipitate depressive symptoms associated with interferon treatment for hepatitis C. Cognitive deficits in schizophrenia are associated with imbalances in the enzymes that break down kynurenine. Kynurenine production is increased in Alzheimer's disease and cardiovascular disease where its metabolites are associated with cognitive deficits and depressive symptoms.

Tezampanel, also known as LY 293558 and NGX-424, is a drug originally developed by Eli Lilly, which is a competitive antagonist of the AMPA and kainate subtypes of the ionotropic glutamate receptor family. Tezampanel was in phase II clinical trial for treatment migraine, but this study was discontinued. Also this drug has several others potential pharmacological actions, one of them is anxiety disorders

MPEP (2-methyl-6-(phenylethynyl)pyridine) was one of the first compounds found to act a selective antagonist for the metabotropic glutamate receptor subtype mGluR5. It was under development by Novartis in the late 1990's. MPEP was found to produce neuroprotective effects following acute brain injury in animals. MPEP was also found to have positive effects on animal models of depression, anxiety and morphine withdrawl.

Lysergide (LSD) is a semi-synthetic hallucinogen and is one of the most potent drugs known. Recreational use became popular between the 1960s to 1980s, but is now less common. LSD was first synthesized by Albert Hoffman while working for Sandoz Laboratories in Basel in 1938. Some years later, during a re-evaluation of the compound, he accidentally ingested a small amount and described the first ‘trip’. During the 1950s and 1960s, Sandoz evaluated the drug for therapeutic purposes and marketed it under the name Delysid®. It was used for research into the chemical origins of mental illness. Recreational use started in the 1960s and is associated with the ‘psychedelic period’. LSD possesses a complex pharmacological profile that includes direct activation of serotonin, dopamine and norepinephrine receptors. In addition, one of its chief sites of action is that of compound-specific (“allosteric”) alterations in secondary messengers associated with 5HT2A and 5HT2C receptor activation and changes in gene expression. The hallucinogenic effects of LSD are likely due to agonism at 5HT2A and 5HT2C receptors. LSD is also an agonist at the majority of known serotonin receptors, including 5HT1A, 5HT1B, 5HT1D, 5HT5A, 5HT6 and 5HT7 receptors. During the 1960s, LSD was investigated for a variety of psychiatric indications, including the following: as an aid in treatment of schizophrenia; as a means of creating a "model psychosis"; as a direct antidepressant; and as an adjunct to psychotherapy. LSD is listed in Schedule I of the United Nations 1971 Convention on Psychotropic Substances.

Sunepitron (CP-93,393) is an anxiolytic drug with highly selective serotonin 5-hydroxytryptamine 1A autoreceptor agonist, alpha2-adrenergic antagonist, and dopamine D2 agonist properties. Sunepitron hydrochloride had been in Phase III clinical trials by Pfizer for the treatment of anxiety disorder and depression. However, this research has been discontinued.

Tezampanel, also known as LY 293558 and NGX-424, is a drug originally developed by Eli Lilly, which is a competitive antagonist of the AMPA and kainate subtypes of the ionotropic glutamate receptor family. Tezampanel was in phase II clinical trial for treatment migraine, but this study was discontinued. Also this drug has several others potential pharmacological actions, one of them is anxiety disorders

Isamoltan (CGP 361A) is a β-adrenoceptor and serotonin 1B receptor antagonist. Isamoltane has reported activity as an anxiolytic in man. Isamoltan had been in phase III clinical trials for the treatment of anxiety. However, this research has been discontinued.