Answer to Question 1
Obsessions are persistent and intrusive thoughts, urges, or images that are experienced as intrusive and unwanted, and generally cause significant anxiety or distress. Compulsions are repetitive, purposeful, and intentional behaviors (e.g., hand washing) or mental acts (e.g., repeating words silently) that are performed in response to obsessions in an attempt to suppress or neutralize them. Most children with OCD have multiple obsessions and compulsions, and certain compulsions are commonly associated with specific obsessions. For example, washing and cleaning rituals are likely to be associated with contamination obsessions, such as a concern with dirt or germs, a concern or disgust with body wastes or secretions (e.g., urine, feces, saliva), or an excessive concern about chemical or environmental contamination.
Answer to Question 2
As specified in DSM-5, common types of specific phobias in young people include fears of animals or insects (e.g., dogs or spiders); fears of natural events (e.g., heights or thunderstorms); fears of blood, injuries, or medical procedures (e.g., seeing blood or receiving an injection); and fears of specific situations (e.g., flying in airplanes, riding on a bus). Both similarities (e.g., age at onset, gender, treatment response) and differences (e.g., focus of fear, physiological reaction, neural response patterns, impairment, comorbidity) have been found across these types, with natural environment and animal phobias having the most in common with other types, and blood, injury, and injection phobias the least (LeBeau et al., 2010; Lueken et al., 2011).
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