A solid, oral, extended release pharmaceutical tablet comprising: a core comprising: i) a therapeutically effective amount of an active agent selected from ketamine, and pharmaceutically acceptable salts thereof; ii) at least one high molecular weight polyethylene oxide that is cured, wherein said high molecular weight PEO has an approximate molecular weight of from 2 million to 7 million, based upon rheological measurements, and is present in an amount of at least 30% by weight of the core; optionally, a coating on said core; wherein said tablet is crush resistant and has a breaking strength of at least 200 N; wherein the tablet comprises the active agent at a concentration of 10% to 20% by weight of the core; and wherein when said tablet is administered to a patient said tablet provides a pharmacokinetic parameter selected from the group consisting of: i) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of a single dose of 60 mg or 120 mg or 240 mg; ii) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of 5 doses of 60 mg administered every 12 hours; iii) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of 5 doses of 120 mg administered every 12 hours; iv) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of 5 doses of 240 mg administered every 12 hours; v) after administration of a single dose of about 60 mg a mean ratio of norketamine Cmax: ketamine Cmax of 8.7, or a ratio of norketamine Cmax: ketamine Cmax of between 4 to 15; vi) after administration of a single dose of about 60 mg a mean ratio of norketamine AUC:ketamine AUC of 11.8, or a ratio of norketamine AUC:ketamine AUC of between 7 to 15; vii) after administration of a single dose of 60 mg, 120 mg, or 240 mg a mean ratio of norketamine Cmax: ketamine Cmax of 9.6; and viii) after administration of a single dose of 60 mg, 120 mg, or 240 mg a mean ratio of norketamine AUC:ketamine AUC of 11.8. a core comprising: i) a therapeutically effective amount of an active agent selected from ketamine, and pharmaceutically acceptable salts thereof; ii) at least one high molecular weight polyethylene oxide that is cured, wherein said high molecular weight PEO has an approximate molecular weight of from 2 million to 7 million, based upon rheological measurements, and is present in an amount of at least 30% by weight of the core; i) a therapeutically effective amount of an active agent selected from ketamine, and pharmaceutically acceptable salts thereof; ii) at least one high molecular weight polyethylene oxide that is cured, wherein said high molecular weight PEO has an approximate molecular weight of from 2 million to 7 million, based upon rheological measurements, and is present in an amount of at least 30% by weight of the core; optionally, a coating on said core; wherein said tablet is crush resistant and has a breaking strength of at least 200 N; wherein the tablet comprises the active agent at a concentration of 10% to 20% by weight of the core; and wherein when said tablet is administered to a patient said tablet provides a pharmacokinetic parameter selected from the group consisting of: i) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of a single dose of 60 mg or 120 mg or 240 mg; ii) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of 5 doses of 60 mg administered every 12 hours; iii) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of 5 doses of 120 mg administered every 12 hours; iv) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of 5 doses of 240 mg administered every 12 hours; v) after administration of a single dose of about 60 mg a mean ratio of norketamine Cmax: ketamine Cmax of 8.7, or a ratio of norketamine Cmax: ketamine Cmax of between 4 to 15; vi) after administration of a single dose of about 60 mg a mean ratio of norketamine AUC:ketamine AUC of 11.8, or a ratio of norketamine AUC:ketamine AUC of between 7 to 15; vii) after administration of a single dose of 60 mg, 120 mg, or 240 mg a mean ratio of norketamine Cmax: ketamine Cmax of 9.6; and viii) after administration of a single dose of 60 mg, 120 mg, or 240 mg a mean ratio of norketamine AUC:ketamine AUC of 11.8. i) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of a single dose of 60 mg or 120 mg or 240 mg; ii) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of 5 doses of 60 mg administered every 12 hours; iii) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of 5 doses of 120 mg administered every 12 hours; iv) a mean tmax of said active agent between 1.5 and 3.5 hours after administration of 5 doses of 240 mg administered every 12 hours; v) after administration of a single dose of about 60 mg a mean ratio of norketamine Cmax: ketamine Cmax of 8.7, or a ratio of norketamine Cmax: ketamine Cmax of between 4 to 15; vi) after administration of a single dose of about 60 mg a mean ratio of norketamine AUC:ketamine AUC of 11.8, or a ratio of norketamine AUC:ketamine AUC of between 7 to 15; vii) after administration of a single dose of 60 mg, 120 mg, or 240 mg a mean ratio of norketamine Cmax: ketamine Cmax of 9.6; and viii) after administration of a single dose of 60 mg, 120 mg, or 240 mg a mean ratio of norketamine AUC:ketamine AUC of 11.8.