Anxiety disorders with ADHD

Although ADHD generally is considered a childhood disorder, symptoms can persist into adolescence and adulthood. The prevalence of adulthood ADHD is estimated to be 4%, with 60% of adults having manifested symptoms of ADHD from childhood.8,9 Further, problems associated with ADHD (e.g., social, marital, academic, career, anxiety, depression, smoking, and substance-abuse problems) increase with the transition of patients into adulthood. 

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. 

Substance-Induced Anxiety Disorder. Numerous medicines and drugs of abuse can produce panic attacks. Panic attacks can be triggered by central nervous system stimulants such as cocaine, methamphetamine, caffeine, over-the-counter herbal stimulants such as ephedra, or any of the medications commonly used to treat narcolepsy and ADHD, including psychostimulants and modafinil. Thyroid supplementation with thyroxine (Synthroid) or triiodothyronine (Cytomel) can rarely produce panic attacks. Abrupt withdrawal from central nervous system depressants such as alcohol, barbiturates, and benzodiazepines can cause panic attacks as well. This can be especially problematic with short-acting benzodiazepines such as alprazolam (Xanax), which is an effective treatment for panic disorder but which has been associated with between dose withdrawal symptoms. 

Approximately three-quarters of children with OCD have comorbid diagnoses. These include tic disorders (24%-30%) and mood disorders, especially major depression (26%-29%). Riddle and colleagues (1990) found that 38% of children with OCD have other anxiety disorders, while Swedo (1989) more specifically identified increased rates of simple phobias (17%), overanxious disorder (16%), and separation anxiety disorder (7%). Other reported comorbidities include specific developmental disabilities, adjustment disorder with depressed mood, oppositional defiant disorder, attention-deficit hyperactivity disorder (ADHD), conduct disorder, and enuresis/encopresis (Swedo et ah, 1989b Riddle et ah, 1990). 

Studies at the National Institutes of Health (NIH) have detailed the clinical characteristics of patients in the PANDAS subgroup (Swedo et al., 1998). The rate of neuropsychiatric comorbidity in this population is quite striking. Twenty of the 50 children (40%) met DSM-IV criteria for ADHD and/or oppositional defiant disorder (ODD), 18 (36%) for major depressive disorder, 14 (28%) for overanxious disorder, and 10 (20%) for separation anxiety disorder. Six children (12%) were enuretic, often episodically and closely correlated with periods of OCD and tic exacerbations. Depressive symptoms, ADHD, and separation anxiety disorder also waxed and waned in concert with the OCD/ tic symptoms. In addition, exacerbations of OCD and tics were accompanied frequently by the acute onset of choreiform movements (clinically distinct from chorea), emotional lability and irritability, tactile/sensory defensiveness, motoric hyperactivity, messy handwriting, and symptoms of separation anxiety (Perlmutter et al., 1998 Becker et al., 2000). 

There are a number of useful standardized scales to monitor severity and treatment outcomes, (reviewed by Conners [1998] and Barkley [1998]) Because of the overlap with other disorders, an ADHD-specific scale is strongly recommended (such as the Conners, SNAP, Dupaul scales) in which symptom items are based on the DSM criteria and do not include items of other disorders (such as anxiety or mood) or nonspecific functional items. Some ADHD scales provide separate ratings of oppositionality or aggression (SNAP, Conners). It may be helpful to monitor symptoms from non-ADHD conditions as well as functional deficits, and thus a broad-spectrum scale may also be employed but should not be used as the primary measure of ADHD severity or anti-ADHD treatment. Normed rating scales provide comparative information on severity based on age and gender however, such tests are not diagnostic and are not a substitute for the clinical interview. 

Inattentiveness, impulsivity, hyperactivity 50% will continue to manifest the disorder into adulthood Stimulants (70% response for uncomplicated ADHD caution in patients with tic disorders) TCAs (70% response, first line for patients with comorbid MD or anxiety disorders, and for patients with ADHD + tics) requires serum levels and cardiovascular monitoring Bupropion Clonidine, guan-facine (first line for patients with ADHD + tics) MAOIs Combined pharmacotherapy for treatment-resistant cases... 

The largest juvenile, controlled trial of a TCA reported favorable results with DMI in 62 clinically referred children with ADHD (Biederman et al., 1989). Many of these children had previously failed to respond to psychostimulant treatment. Sixty-eight percent of DMI-treated patients were considered very much or much improved, compared with only 10% of placebo patients (p < 0.001), at an average daily dose of 5 mg/kg. In a further analysis, neither comorbidity with conduct disorder, depression, or anxiety, nor a family history of ADHD yielded differential responses to DMI treatment (Biederman et al., 1993b). In addition, DMI-treated ADHD patients showed a substantial reduction in depressive symptoms compared with placebo-treated patients. 

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. 

If relapse does occur, it should first be determined whether the patient was compliant with treatment. If the patient was not compliant, antidepressant medication should resume. If the patient was compliant and had been previously responding to the medication (without significant side effects), the existence of ongoing stressors (e.g., conflict, abuse) or comorbid medical or psychiatric disorders should be considered (anxiety disorder, ADHD, substance abuse, dysthymia, bipolar disorder, eating disorder). 

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 conclusion stands in contrast to the statements made in an earlier review (Kauffmann and Hallahan, 1979) that behavioral therapeutic techniques have an important role to play in ADHD, and partly contradicts the results of some more recent studies. As summarized in Chapter 7 (p. 250 f.), the US MTA study did not detect any significant difference between combined treatments and treatment with methylphenidate alone with regard to their effects on ADHD symptoms however combined treatments had some advantage over drug alone on features such as anxiety disorders, social skills, consumer (mainly parent) satisfaction and possibly academic achievement (Pelham et al., 2000). Additional statistical analysis of the MTA study by responders and in terms of composite outcome measures also revealed additional benefit of combined treatments over drug therapy alone (Jensen et al., 2001). 

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." " ... 

A word about prevalence mental illness is more common than many people imagine. The current prevalence estimates are that about half the U.S. population meets the criteria for at least one mental disorder during a lifetime, with about 25 percent of the population meeting the criteria for at least one mental disorder during any given year.1 Of these disorders, the most prevalent are apparently anxiety disorders, followed by mood disorders (for example, major depressive disorder), impulse-control disorders (for example, attention deficit hyperactivity disorder [ADHD]), and substance disorders (for example, alcohol abuse). In contrast, the prevalence of psychosis as I define it here is only 2—3 percent of the U.S. population, and the world prevalence is about the same. 

A 10-year-old boy with ADHD, oppositional defiant disorder, and generalized and separation anxiety disorders started taking OROS methylphenidate 18 mg/day and fluoxetine 10 mg/day. Four days later, he had an acute episode of intense hallucinations 3 hours after taking the medications. His mother reported that the visual hallucinations lasted about 1 hour and the tactile hallucinations more than 2 hours. Two days later he had a similar episode. His mother withdrew the medications for 10 days, during which time he was symptom free. When OROS methylphenidate 18 mg/day monotherapy was restarted he did not report any hallucinations. Mirtazapine 15 mg/day was added for symptoms of anxiety and sleep disturbances. During the next 2 months his condition improved and he had no further hallucinations. 

Children with internalizing disorders such as depression and anxiety are often the best informants about their affective states. However, if children experience depressed or anxious mood as their normal state, no baseline frame of reference is available for comparison. Children and adolescents with externalizing disorders such as ADHD and conduct disorder are often poor informants and may be minimally cooperative with the interview. Since they often deny the existence of a problem and blame others, reports from other informants (parent, school) are essential. 

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