DIFFERENTIAL DIAGNOSIS
Medical disorders associated with anxiety. It is important to differentiate the various medical disorders that can present with anxiety symptoms and the anxiety disorders that are attributable to medical conditions. The mnemonic DIVINE MD TEST, described in Table 2, can be helpful in assessing the differential diagnosis.9
The list of drugs suspected of causing anxiety is extensive.10 Drugs commonly associated with anxiety include stimulants such as amphetamine, cocaine, methamphetamine, and caffeine(Drug information on caffeine). Drugs such as lysergic acid diethylamide (LSD) and 3,4-methylenedioxymethamphetamine (MDMA, or “ecstasy”) can also cause acute and chronic anxiety. Prescription medications to consider include sympathomimetics, antihypertensives, and NSAIDs.10
It is of paramount importance to establish a causal relationship between the onset of anxiety symptoms and the timing of intake of prescribed medications before any medication is discontinued. The dosage of the suspected medication may be gradually tapered and withdrawn and the patient monitored for a correlation between relief of symptoms and washout (about 5 half-lives) to confirm or refute the diagnosis. For an accurate assessment of anxiety symptoms in patients who use illicit drugs, a period of 4 to 6 weeks of total abstinence is required.
Psychiatric conditions associated with anxiety. Anxiety symptoms may be secondary to other psychiatric disorders, including11:
• Adjustment disorders with anxious mood.
• Anxious mood associated with depressive or bipolar disorders.
• Anxiety attributable to alcohol(Drug information on alcohol)ism and other substance abuse disorders.
• Bereavement caused by a single loss or multiple losses.
• Neuropsychiatric disorders associated with dementia, mild cognitive impairment, and delirium.
Depressive disorders and anxiety disorders often coexist; however, this combination is not well recognized despite its significant impact on increasing disability and disruption of normal functioning. When these primary psychiatric conditions are untreated, the associated secondary anxiety symptoms may progress and lead to a more severe anxiety disorder. It is also common for an anxiety disorder to accompany another anxiety disorder, an eating disorder, or a substance abuse disorder, especially alcohol dependence.
PRIMARY ANXIETY-SPECTRUM DISORDERS
The following primary anxiety disorders are described in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR)11:
• Generalized anxiety disorder.
• Agoraphobia without history of panic disorder.
• Panic disorder without or with agoraphobia.
• Specific phobias and social phobia (social anxiety disorder).
• Obsessive-compulsive disorder.
• Acute stress disorder.
• Posttraumatic stress disorder.
Generalized anxiety disorder. Patients who have generalized anxiety disorder experience chronic excessive nervousness, exaggerated worry, tension, and irritability that appear to have no cause or are more intense than the situation warrants.11 Their worries are often related to their perceived inability to perform with punctuality and competence in various settings and circumstances. Over the course of the disorder, physical signs—such as restlessness, difficulty in falling or remaining asleep, headaches, trembling, twitching, muscle tension, or sweating— often develop, which lead to further worries. Patients with generalized anxiety disorder may also have other anxiety and mood disorders.7
Agoraphobia. The term “agoraphobia,” which originally came from the Greek language to describe “fear of the marketplace,” became generalized to describe fear of any open or public space. The condition can be quite disabling. Patients with agoraphobia fear being in a situation in which they experience anxiety or panic and from which escape might be difficult or embarrassing. As a result, they avoid those situations that cause anxiety or panic. It is the fear of the anxiety that leads to agoraphobia. Agoraphobia can be accompanied by panic disorder and panic attacks, or it can occur alone without a history of panic attacks.1,11
Panic disorder. Patients with panic disorder usually describe periods of intense fear or discomfort that they call panic attacks.1,7,12 Very often, they seek medical treatment because they fear that their physical symptoms—which may include chest pain, dizziness, nausea, chills, trembling, and palpitations—are caused by a heart attack.
Patients may worry about recurrent and often unexpected panic attacks. The anticipatory anxiety and intense fear of future attacks may lead to the development of phobic avoidance. The combination of panic symptoms and the phobic avoidance can impair the patient’s professional, social, and familial functioning.1,7,13
Specific phobias. Phobias are manifested by irrational fears when a person is exposed to or is in close physical contact with specific objects or situations that trigger intense anxiety.11,13 The intense anxiety can also be triggered when the person sees or hears the name of the object, or sees pictures of the object. Phobic avoidance develops, and the patient will altogether avoid all the specific things or situations that trigger the intense anxiety. The avoidance leads to an ongoing impairment in the patient’s ability to function in settings where exposure to the specific object occurs.1,14
Social phobia (social anxiety disorder). Social phobia is manifested by excessive, persistent fear of social and performance situations that is so severe that it disrupts daily life and relationships.11,15 Persons with social anxiety have a persistent, intense, and ongoing fear of being extremely embarrassed or being watched, judged by others, or humiliated by their own actions.14,15 The most common social phobia is fear of public speaking.15
Obsessive-compulsive disorder. Patients with obsessive-compulsive disorder experience repetitive ideas (obsessions) that are distressing and provoke intense symptoms of anxiety. To counteract the anxiety, patients use certain sets of actions, or rituals, and repetitive behaviors (compulsions).11 The repetitive behaviors diminish the anxiety temporarily, only to have it return within a relatively short period of time. As a result, patients often continue the compulsive behaviors, which consume most of their time, or they avoid situations with which the obsessions are associated, thus constricting their activities and range of behaviors.1,11
Patients with obsessive-compulsive disorder may have only obsessions or only compulsions or both obsessions and compulsions.11 They most often experience obsessions that they must avoid contamination, that actions or items need to be checked for completion, or that they must engage in certain detailed and elaborate activities to prevent future harm to oneself or others. Repetitive, intrusive thoughts or images about violence or sexual actions, or urges to engage in violence or sexual actions are also common.
Despite patients’ awareness of the irrational nature of their condition, they feel unable to control their obsessions or to prevent their compulsions.7,16 The disorder hinders mental, social, and academic performance; if untreated, it may lead to permanent disability because of the loss of meaningful interpersonal relations and employment.16
