| opioid antagonists | Agents such as naloxone and naltrexone which have high affinity for opiate receptors but do not activate these receptors. These drugs block the effects of exogenously administered opioids such as morphine, heroin, meperidine, and methadone, or of endogenously released endorphins and enkephalins. (05 Mar 2000) |
|---|---|
| opioid partial agonist | <pharmacology> A compound that has an affinity for and stimulates physiologic activity at the same cell receptors as opioid agonists but that produces only a partial (i.e., submaximal) bodily response. (16 Dec 1997) |
| opioid peptides | The endogenous peptides with opiate-like activity. The three major classes currently recognised are the enkephalins, the dynorphins, and the endorphins. Each of these families derives from different precursors, proenkephalin, prodynorphin, and pro-opiomelanocortin, respectively. There are also at least three classes of opioid receptors, but the peptide families do not map to the receptors in a simple way. (12 Dec 1998) |
| opioid receptor | <pharmacology> A membrane protein, widely distributed in animal cells, but especially in the brain (enkephalin receptors) and gut. The natural ligands are the opiate peptide neurotransmitters, but the name is given because opiates are potent agonists that occupy the receptors and mimic the action of the natural transmitters. (18 Nov 1997) |
| opioid-related disorders | Disorders related or resulting from abuse or mis-use of opioids. (12 Dec 1998) |
| affective personality disorder | A disturbance of feelings or mood expressed as a milder form of depression and related emotional features that colour the whole psychic life and for which psychosocial stressors are believed to play the major role. (05 Mar 2000) |
| alcohol amnestic disorder | <psychiatry> A mental disorder with brain damage characterised by amnesia, compensatory confabulation, disturbance of attention, and peripheral neuritis. It is usually associated with alcoholism and dietary deficiencies. (12 Dec 1998) |
| antisocial personality disorder | <psychiatry> An individual who engages in deviant behaviour with lack of remorse. (13 Jan 1998) |
| asthenic personality disorder | A personality type characterised by low energy level, easy fatigability, incapacity for enjoyment, lack of enthusiasm, and oversensitivity to physical and emotional stress. When appearing in marked form it becomes a psychological disorder (asthenic personality disorder), also called dependent personality. Synonym: asthenic personality disorder, dependent personality disorder. (05 Mar 2000) |
| attention deficit disorder | An inability to control behaviour due to difficulty in processing neural stimuli. (12 Dec 1998) |
| attention deficit disorder with hyperactivity | A behaviour disorder originating in childhood in which the essential features are signs of developmentally inappropriate inattention, impulsivity, and hyperactivity. Although most individuals have symptoms of both inattention and hyperactivity-impulsivity, one or the other pattern may be predominant. The disorder is more frequent in males than females. Onset is in childhood. Symptoms often attenuate during late adolescence although a minority experience the full complement of symptoms into mid-adulthood. (12 Dec 1998) |
| attention deficit hyperactivity disorder | <psychiatry> A condition seen in children where there is increased motor activity in association with poor attention span. Often treated with amphetamine medications. (27 Sep 1997) |
| autistic disorder | autism, infantile autism |
| autonomic disorder | Disorganization of autonomic processes. (05 Mar 2000) |
| avoidant disorder of adolescence | A mental disorder occurring in childhood or adolescence characterised by an excessive shrinking away from contact with people who are unfamiliar. Synonym: avoidant disorder of adolescence. (05 Mar 2000) |