The ASAP Dictionary of Anxiety and Panic Disorders

Obsessive - descriptive of a persistent thought, image, or impulse. Obsessions can be constructive (as in the case of an obsessive artist or scientist) or detrimental (as in the sense of an obsessive disorder or OCD).

Obsessive Compulsive Disorder (OCD) - a disorder characterized by excessively obsessive and compulsive tendencies. Like many anxiety disorders, OCD may have a significant genetic component or, in children, may be related to Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS). Many people experience relief with cognitive behavioral therapy and/or medication. Also see CY-BOCS, YBOCS, scrupulosity.

Obsessive Disorder - a disorder characterized by excessively persistent and unwanted thoughts, images, or impulses that produce anxiety. Such obsessions may involve dirt, contamination, disease, aggression, orderliness, sex, religion, etc. Also see intrusive memory, intrusive thought.

Occipital Lobe - the hind lobe of the cerebrum. Contains the visual cortex.

OCD - see Obsessive Compulsive Disorder.

Ochlophobia - a phobia of crowds.

Old Hag - see sleep paralysis.

Oneirology - see dream analysis.

Oneroi - the Oneroi were a group of Greek gods who personified dreams. These sons of Hypnos included Morpheus (shaper of dreams), Ikelos (realistic dreams), Phantasos (strange dreams) and Phobetor (frightening dreams). Also see mythology.

Operant Conditioning - a trained association between a behavior and a consequence. Consequences are typically labeled "positive reinforcement" (added stimulus encourages behavior), "negative reinforcement" (removed stimulus encourages behavior), "positive punishment" (added stimulus discourages behavior) and "negative punishment" (removed stimulus discourages behavior). Operant conditioning is also known as Response-Stimulus (RS) conditioning or, similarly, Stimulus-Response (SR) conditioning. Also see aversion therapy, behavioral therapy, conditioning. Contrast with classical conditioning.

Operational Fatigue - an alternate name for PTSD, attributed to aviation personnel during WWII.

Ophidiophobia - a phobia of snakes.

Opium - a sedative obtained from the juices of the poppy plant (Papaver somniferum). Opium has been used throughout history as an anxiolytic medication and recreational drug. CAUTION: as a dopamine agonist, opium can be highly addictive.

Orthostatic Hypotension - a drop in blood pressure (technically, 20mm Hg in systolic BP or greater) which occurs when rising to a standing position and can cause a person to faint. Also see hypotension.

OTC - see Over The Counter.

Outpatient - anyone treated, but not staying, at a hospital, clinic or similar facility. Contrast with inpatient.

Over The Counter (OTC) - regarding medications legally sold without a prescription.

Oxytocin - a hormone involved in muscle contraction and nerve sensitivity. Oxytocin production is stimulated by dopamine.

The ASAP Dictionary of Anxiety and Panic Disorders