ration anxiety disorder  and selective mutism). Since in dividuals with anxiety disorders
typically overestimate the danger in situations  they fear or avoid, the primary determina-
tion of whether the fear or anxiety is excessive or out of proportion is made by the clinician,
taking cultural contextual fa ctors into account. Many of the anxiety disorders develop in
childhood and tend to persist if not treated. Most occur more frequent ly in females than in
males (approximately 2:1 ratio). Each anxiety disorder is diagnosed only when the symp-
toms are not attributable to th e physiological effects of a substance/medication or to another
medical condition or are not better explained by another mental disorder. 
The chapter is arranged developmentally, with disord ers sequenced according to the
typical age at onset. The individual with sepa ration anxiety disorder is fearful or anxious
about separation from attachment figures to a degree that is developmentally inappro-
priate. There is persistent fear or anxiety about harm coming to attachment figures and
events that could lead to loss of or separati on from attachment figures and reluctance to go
away from attachment figures, as well as nightmares and physical symptoms of distress. Al-
though the symptoms often deve lop in childhood, they can be  expressed throughout adult-
hood as well.
Selective mutism is characterized by a consiste nt failure to speak in  social situations in
which there is an expectation to speak (e.g.,  school) even though the individual speaks in
other situations. The failure to  speak has significant consequences on achievement in aca-
demic or occupational settings or otherwise interferes with normal social communication. 
Individuals with specific phobia are fearful or anxious about or avoidant of circum-
scribed objects or situations. A specific cognitive ideation is not featured in this disorder,