Separation anxiety disorder (SAD) is defined in the DSM-IV as “developmentally inappropriate and excessive anxiety concerning separation from home or from those to whom the individual is attached” (7). The essential clinical feature of separation anxiety is excessive worry about losing or being permanently separated from a major attachment figure. Manifestations of this anxiety include recurrent excessive distress and/or repeated somatic complaints when separation from home or major attachment figures occurs or is anticipated. SAD may also include nightmares involving the theme of separation, and a persistent refusal to go to sleep or be alone without having a major attachment figure nearby (7). School refusal and excessive somatic complaints in the context of actual or anticipated separations are the most common reasons for parents and children to seek treatment for SAD (Table 5.5.1.1).

Further criteria for a diagnosis of separation anxiety are that the “disturbance” must last at least 4 weeks and cause clinically significant impairment in social, academic, and occupational arenas. The onset must occur before 18 years of age, and it is generally not expected to occur below 6 years of age. If the onset occurs before the child is 6 years old, it is labeled as early onset separation anxiety disorder (7). The lower age boundary is established to account for the fact that such anxiety is age-appropriate from 7 months to 6 years of age, and therefore should not necessarily be viewed as unusual or a problem below the age of 6 (19,20,21).

It has been suggested that childhood SAD is a risk factor for the development of panic disorder or agoraphobia as an adolescent or adult (22,23,24,25). This is supported by physiological studies demonstrating an increased
sensitivity to carbon dioxide exposure in children with SAD similar to that seen in panic disorder patients (26). Such increased sensitivity to carbon dioxide, as well as other manifestations of respiratory dysfunction, occurs selectively in pediatric SAD but not in pediatric social phobia. This emphasizes the validity of nosological distinctions between SAD and social phobia. However, longitudinal studies of children with SAD have not necessarily supported this relationship with panic disorder (27). Similarly, family-based studies provide mixed support for the association between SAD in children and panic disorder in their parents (28,29).

Social phobia, or social anxiety disorder, is defined in the DSM-IV as a persistent fear of one or more social situations in which a person is exposed to unfamiliar persons or to scrutiny by others. The term social anxiety disorder was added to this diagnosis in DSM-IV to emphasize the distinction between social phobia and other forms of phobias, which are classified as specific phobias. In social phobia/social anxiety disorder, the threat of exposure to such situations provokes anxiety, and even panic attacks. Feared social situations include public speaking and performance, attending social gatherings, and speaking to strangers. Social phobia interferes with daily functioning because sufferers try to avoid anxiety-provoking situations or endure them with intense distress (7). Children and adolescents with social phobia tend to focus excessively on concerns about embarrassment, negative evaluation, and rejection. They often experience increased heart rate, blushing, lightheadedness, gastrointestinal distress, and tremulousness when faced with a feared situation (30). Untreated, social phobia may result in school refusal, premature termination of formal education, and failure to enter the workforce. In older adolescents, social phobia can interfere with occupational development and dating relationships, which creates later relationship difficulties and dysfunction (31).

The development of social phobia in adolescence or adulthood has been significantly associated with the temperamental characteristic of behavioral inhibition to the unfamiliar, seen in infants as young as 21 months (31,32). Behavioral inhibition is described as a tendency to exhibit withdrawal and excessive autonomic arousal to challenge or novelty (33). Moreover, some evidence suggests that children and adolescents with social phobia, unlike children and adolescents with SAD, exhibit increased fear when challenged in the laboratory with social stressors (34).

Differential diagnosis of social phobia is often complicated by social skills deficits and anxiety characteristic of pervasive developmental disorders (PDD) such as high-functioning autism and Asperger disorder. Evidence of some relationship between these classes of disorders emerges from family studies, where PDD in children has been linked to social phobia in parents (35). On the other hand, these disorders do represent distinct conditions. Social skills deficits in children with social phobia result from delayed learning and refinement of social skills due to anxiety, whereas deficits found in children with PDD are more likely due to neuropsychiatric impairment (31). If the child has the capacity for social relationships with familiar people, the diagnosis of social phobia is made, rather than PDD.

Generalized anxiety disorder (GAD) is characterized by a pattern of excessive and uncontrollable worry that causes impairment in daily functioning. To meet diagnostic criteria, this pattern of extreme worry must be accompanied by at least one associated symptom and must last for at least six months. The worry associated with GAD is not confined to one topic area and is often focused on competence, approval, future events, and new or unfamiliar situations. These children frequently seek reassurance from others, although this reassurance usually provides only fleeting relief from the oppressive worries (36,37). Somatic complaints such as headaches, stomach distress, sleep difficulties, and muscle aches are common. Patients also may report feeling on edge and unable to relax, and often seem irritable when worrying. As a result of these physical symptoms, these children often see their pediatrician rather than a mental health professional (38). Prior to DSM-IV, children and adolescents presenting with these symptoms typically were classified as suffering from overanxious disorder, a condition that was replaced by GAD in DSM-IV. Despite this nosological convention, symptoms for the two conditions exhibit only moderate overlap, and it remains unclear the degree to which these two constructs identify overlapping or distinct populations of children.

The results of a multivariate genetic analysis show a close genetic link between GAD and depression, suggesting that they are influenced by the same genetic factor (39). These findings are indicative of a more general
predisposition toward anxiety and depression than specific to GAD. In light of findings that demonstrate that adolescent GAD precedes later depression (6), these genetic factors may predispose children or adolescents to develop GAD that in turn leads to depressive symptoms. Additional prospective studies of children with GAD are needed to tease apart this complex genetic linkage. This association may reflect the impact of broad personality factors, such as neuroticism or negative emotionality, on risk for both GAD and major depressive disorder. Such personality constructs have been linked to specific genetic factors, such as a functional polymorphism in the promoter for the serotonin transporter gene (see following).

Specific phobia is defined as a marked and persistent fear that is excessive or unreasonable and interferes in daily life, which is cued by the presence or anticipation of a specific object or situation (flying, animals, heights, sight of blood) (7). Exposure to the phobic stimulus will almost always provoke an immediate anxiety response, such as a panic attack. In children, this response may appear as tantrums, crying, freezing, or clinging. Anxious symptoms can also include increased heart rate, sweating, hyperventilating, and upset stomach. Unlike adults with specific phobia who are usually aware that the fear is abnormal and maladaptive, children often do not recognize that their fear is excessive or unreasonable. For adolescents and children under 18 the phobia must have persisted for at least 6 months.

Specific phobias are grouped into five categories. In animal-type, the fear is cued by animals or insects. For natural-environment-type, the fear is cued by objects in the natural environment (storms, heights, water). Blood-injection-injury type involves a fear of seeing blood or an injury, or of receiving an injection. This type of specific phobia may involve feelings of disgust and a vasovagal response to feared stimuli. Situational type is cued by a specific situation (flying, using elevators, going over bridges). There is a fifth category, “other type,” which encompasses all other objects or situations, such as choking or costumed characters (7,40,41,42). Evolutionary theorists speculate that these five types of phobias correspond to evolutionary dangers that have become embedded in the genetic code. Fear of spiders, snakes, and blood are thus a product of innate survival tendencies. The fear is not a rational process, but rather a genetically coded reaction (41).

Panic disorder refers to the experience of unexpected panic attacks accompanied by persistent apprehension about their recurrence or behavioral modifications in daily routine as a result of the attacks. While panic attacks can occur in many conditions, including phobias and social anxiety disorder, the panic attack associated with panic disorder is unique in that it occurs spontaneously without an environmental trigger. For example, panic disorder is uniquely associated with nocturnal panic attacks, which spontaneously awaken a patient from sleep.

A panic attack is a discrete period of intense fear or discomfort that is characterized by the presence of at least four somatic and/or cognitive symptoms. The most commonly reported symptoms among adolescents with panic attacks appear to be trembling, dizziness/faintness, pounding heart, nausea, shortness of breath, and sweating (43,44). Cognitive symptoms, such as a fear of going crazy or dying, are reported less frequently than somatic ones (44). A diagnosis of panic disorder with agoraphobia is indicated if the patient avoids places or situations in which escape might be difficult or embarrassing. The most commonly avoided settings include those involving large groups of people unknown to the patient, such as restaurants, crowds, and auditoriums (43).

The most difficult distinction to make when diagnosing panic disorder in youth is the difference between an unexpected panic attack, as required for a diagnosis of panic disorder, and situationally cued attacks that are typical of other anxiety disorders. This task becomes especially challenging given the cognitive predisposition of children to attribute their experiences to external, identifiable, situational factors. Careful attention to the circumstances surrounding attacks will help with this distinction, as panic attacks occurring in the context of another anxiety disorder will occur primarily in the presence of the target stimulus. Additionally, presence of pervasive apprehension about having a panic attack, as opposed to facing a feared stimulus, supports the diagnosis of panic disorder rather than another anxiety disorder.

Panic attacks can also be caused by a variety of medical conditions, including hyperthyroidism, hyperparathyroidism, vestibular dysfunction, seizure disorders, and cardiac abnormalities. Appropriate laboratory tests and physical examinations should be used to rule out these causes prior to assigning a diagnosis of panic disorder. In particular, when panic is accompanied by cardiac symptoms, a discussion with a pediatrician as to the need for EKG and cardiac consultation is encouraged.