Anxiety disorders comorbid conditions

The anxiety disorders are a case in point. They comprise a range of conditions contiguous with the affective disorders and the stress responses (Table 4.1). Much overlap and comorbidity exist. Furthermore, definitions and diagnostic criteria have changed substantially over the years. For example, generalized anxiety disorder is a rare condition in its pure form, but a common condition if comorbid phobic and depressive disorders are accepted. 

Out-patient treatment is substantially cheaper than in-patient management and is generally as effective (Lowman, 1991). A French study on patients with generalized anxiety disorder estimated costs per patient over 3 months to he US 423 for hospitalization, 335 for out-patient services and 43 for medications (Souetre et al, 1994). Comorbid conditions (mostly alcoholism and depression) doubled these direct health-care costs. Over three-quarters of all patients were taking anxiolytic medication. 

The usually accepted prevalences for generalized anxiety disorder (GAD) are around 1.6% for current, 3.1% for 1 year and 5.1% lifetime (Roy-Byrne, 1996). The condition is twice as common in women as in men (Pigott, 1999). A small minority (10%) have GAD alone, and about the same proportion suffer from mixed anxiety and depression. Morbidity is high. About a half of those with uncomplicated GAD seek professional help, but two-thirds of those with comorbid GAD do so. Up to a half take medication at some point. The condition may coexist with other anxiety disorders such as phobias, with affective disorders, or with medical conditions such as unexplained chest pain and irritable bowel syndrome. 

The mean age of onset of bipolar disorder is 20, although onset may occur in early childhood to the mid-40s.1 If the onset of symptoms occurs after 60 years of age, the condition is probably secondary to medical causes. Early onset of bipolar disorder is associated with greater comorbidities, more mood episodes, a greater proportion of days depressed, and greater lifetime risk of suicide attempts, compared to bipolar disorder with a later onset. Substance abuse and anxiety disorders are more common in patients with an early onset. Patients with bipolar disorder also have higher rates of suicidal thinking, suicidal attempts, and completed suicides. 

Bipolar I disorder affects men and women equally bipolar II seems to be more common in women. Rapid cycling and mixed mania occur more often in women. Individuals with bipolar disorder commonly have another psychiatric disease with 78% to 85% reporting another Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) diagnosis during their lifetime. The most common comorbid conditions include anxiety, substance abuse, and eating disorders.2... 

ADHD is rarely encountered without comorbid conditions and often is underdiagnosed. Between 40% and 75% of patients with ADHD will have one or more comorbidities (e.g., learning disabilities, oppositional defiant conduct, anxiety, or depressive disorders).10 It is important to identify other coexisting conditions in patients with ADHD to assist in initial and ongoing selection of treatment. 

The differential diagnosis of panic disorder includes other psychiatric illnesses, medical illnesses, and substances that can cause panic attacks. Also included are medical illnesses that cause symptoms resembling panic attacks. It should be mentioned that these other conditions, which are described below, and panic disorder are not necessarily mutually exclusive. In fact, there is a high rate of comorbidity between panic disorder, other anxiety disorders, and mood disorders. Because panic disorder is frequently accompanied by agoraphobia, the differential diagnosis also includes illnesses that are associated with symptoms resembling the avoidance of the agoraphobic patient. 

Primary care physicians are critical to the successful identification of GAD. Characterized by often-vague physical complaints, GAD must be distinguished from medical illnesses and other psychiatric disorders, though the high rate of comorbidity requires that a thorough evaluation for GAD be completed even when another disorder has been identified. GAD warrants particular consideration for those patients with nonspecific physical complaints who nevertheless have an urgent need for relief that has resulted in repeated office visits. The differential diagnosis for GAD includes other anxiety disorders, depression, and a variety of medical conditions and substance-induced syndromes. 

Comorbid conditions with other anxiety disorders, attention-deficit hyperactivity disorder, and tic disorders... 

The safety and efficacy of combined SSRI and stimulant pharmacotherapy have been addressed in two open studies. Gammon and Brown (1993) reported on the successful addition of fluoxetine to stimulants in the treatment of 32 patients with ADHD with comorbid depressive and anxiety disorders (Gammon and Brown 1993). These children with comorbid conditions had failed to respond to methylphenidate alone. Another report detailed the addition of methylphenidate to SSRI treatment (Findling, 1996). Depressed children and adults with comorbid ADHD were treated with either fluoxetine or sertraline. While depressive symptoms remitted, ADHD symptoms persisted. Methylphenidate was added and successfully treated the ADHD symptoms. In both investigations, the combined treatment was well tolerated. 

Children and adults with PTSD commonly meet criteria for other psychiatric disorders (Breslau et ah, 1991 Goenjian et ah, 1995 Brady, 1997 De Beilis, 1997). In the adult PTSD literature, comorbidity is clearly the rule rather than the exception and multiple comorbidities are the rule within the rule. Kessler et al. (1995) provide data from interviews with over 6000 individuals ages 15-54 in the National Comorbidity Survey indicating that 88% of men and 79% of women with PTSD had at least one comorbid disorder. Affective disorders, anxiety disorders, and substance use disorders are the most common comorbid conditions in individuals with PTSD (Kessler et ah, 1995 Brady, 1997 Solomon and Bleich, 1998). 

Children with PTSD may be more likely to have comorbid conditions because traumatic insults occur in developmentally sensitive periods. Early life trauma is particularly toxic in its effects on development. Adults with severe sexual abuse histories exhibit high rates of debilitating disorders such as depression, anxiety disorders, alcoholism, substance abuse, and personality disorders (Herman and Van der Kolk, 1987 Putnam and Trickett, 1993). 

Tricyclic antidepressants have been used for decades to treat depression and anxiety in the general population, and clomipramine has been used to treat OCD. Clomipramine has been studied with respect to treating school phobia or school refusal (Berney et ah, 1981). Gittleman-Klein and Klein (1971) found imipramine to be superior to placebo in treating school refusal. As the TCAs may improve other disorders such as nocturnal enuresis, ADHD, and sleep disorders, they may be attractive for children with any of these comorbid conditions and anxiety disorder. 

This principle is not applicable in biological psychiatry. One can and should not simply discard the possibility that a biological variable observed in a psychotic condition is linked to a concurrent depression or that one found in depression is in fact related to a comorbid anxiety disorder. The hierarchical principle is a deus ex machina that resolves the problem of comorbidity only in appearance. Comorbidity in itself is merely a descriptive, not an explanatory, term. The multiplicity of psychiatric disorders, as they are presently defined, in so many patients permits a variety of explanations (Van Praag 1996], and thus the term comorbidity conceals more than it discloses. 

Although depression is the most prominent comorbid illness, a variety of other psychiatric conditions may be associated with panic disorder, for example, agoraphobia [60% of patients with panic disorder], other anxiety disorders (20%), and drug and alcohol abuse [15%] [Klerman 1992). 

Anxiety disorders are quite prevalent in the general population and, of course, more so among patients in primary and specialty care. Also, some affect one gender more than the other (see Table 4.3). It is also common in clinical practice to see patients with symptoms that overlap two or more anxiety disorders or an anxiety disorder and another psychiatric condition for example, there is a high degree of comorbidity for depression and anxiety. 

Anxiety disorders are chronic conditions and drug therapy may need to continue for months or even years, particularly for the more intractable disorders such as (XD and PTSD. Response rates are often incomplete, and relapse upon discontinuation of treatment is common. For disorders with multiple symptoms (e.g., PTSD) only some of the symptoms are relieved. Coexistence of anxiety with other mental disorders, particularly depression (18,19), is very common and such comorbidity is predictive of a poorer treatment outcome. 

A therapeutic range should be established for each patient. This range should define concentrations that result in minimal side effects and optimal seizure control. This therapeutic plasma concentration range should be used to identify the appropriate patient-specific dose. Patients should be monitored chronically for seizure control, comorbid conditions, social adjustment (including quality-of-life assessments), drug interactions, compliance, and adverse effects. Periodic screening for comorbid neuropsychiatric disorders such as depression and anxiety is also important. Clinical response is more important than the serum drug concentration. 

It is critical to clarify the diagnosis of ADHD in individuals with these symptoms. Inattention and distractibility can be symptoms of an anxiety disorder, depression, or bipolar disorder. - In other cases, these anxiety or mood disorders can coexist with ADHD, just as learning deficiencies and conduct or oppositional disorders are common comorbid conditions. The presence of multiple comorbid conditions, particularly conduct or oppositional disorder, may increase the likelihood of ADHD chronicity. ... 

Over 90% of children with Tourette s disorder have coexisting conditions such as ADHD (75%), mood disorders (60%), obsessive-compulsive disorder (40%), other anxiety disorders, or a combination of comorbidities." " Tourette s disorder itself does not cause diminished intellectual functioning however, the severity of tics and associated illnesses can result in significant impairment in school functioning, sometimes necessitating special education classes." " ... 

Identify comorbid psychiatric conditions (e.g., depression, anxiety disorder, substance abuse, or bipolar disorder). 

Anxiety can be a presenting feature of several major psychiatric illnesses. Anxiety symptoms are extremely common in patients with mood disorders, schizophrenia, delirium, dementia, and substance-use disorders. Most psychiatric patients will have two or more concurrent psychiatric disorders (comorbidity) within their lifetime. It is important to diagnose and treat all comorbid psychiatric conditions in patients with anxiety disorders. 

Generalized SAD is associated with significant morbidity, and patients should be treated aggressively. Obstacles to effective treatment include patient avoidance of therapy secondary to fear and shame, treatment directed toward somatic symptoms or comorbid conditions, and financial barriers. Patients with SAD often respond to treatment more slowly and less completely than patients with other anxiety disorders. Therefore it is important to set reasonable expectations for response to therapy. The patient s symptoms, prior treatments, comorbid conditions, and history of snbstance abnse direct treatment selections. 

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