Anxiety is an emotion characterized by an unpleasant state of inner turmoil, often accompanied by nervous behavior such as pacing back and forth, somatic complaints, and rumination. It is the subjectively unpleasant feelings of dread over anticipated events, such as the feeling of imminent death.[need quotation to verify] Anxiety is not the same as fear, which is a response to a real or perceived immediate threat, whereas anxiety involves the expectation of future threat. Anxiety is a feeling of uneasiness and worry, usually generalized and unfocused as an overreaction to a situation that is only subjectively seen as menacing. It is often accompanied by muscular tension, restlessness, fatigue and problems in concentration. Anxiety can be appropriate, but when experienced regularly the individual may suffer from an anxiety disorder.
Attention deficit hyperactivity disorder (ADHD) is a mental disorder of the neurodevelopmental type. It is characterized by problems paying attention, excessive activity, or difficulty controlling behavior which is not appropriate for a person's age. The symptoms appear before a person is twelve years old, are present for more than six months, and cause problems in at least two settings (such as school, home, or recreational activities) In children, problems paying attention may result in poor school performance.[ Additionally there is an association with other mental disorders and substance misuse. Although it causes impairment, particularly in modern society, many children with ADHD have a good attention span for tasks they find interesting.
Ketamine, sold under the brand name Ketalar among others, is a medication mainly used for starting and maintaining anesthesia. It induces a trance-like state while providing pain relief, sedation, and memory loss. Other uses include for chronic pain and for sedation in intensive care. Heart function, breathing, and airway reflexes generally remain functional during its effects. Effects typically begin within five minutes when given by injection with the main effects lasting up to 25 minutes.