Comorbid anxiety

The tricyclic antidepressants (TCAs), such as imipramine, can alleviate symptoms of ADHD. Like bupropion, TCAs likely will improve symptoms associated with comorbid anxiety and depression. The mechanism of action of TCAs is in blocking norepinephrine transporters, thus increasing norepinephrine concentrations in the synapse the increase in norepinephrine is believed to alleviate the symptoms of ADHD. TCAs have been demonstrated to be an effective non-stimulant option for ADHD but less effective than stimulants. However, their use in ADHD has declined owing to case reports of sudden death and anticholinergic side effects6,13 (Table 39-3). Further, TCAs may lower seizure threshold and increase the risk of car-diotoxicity, (e.g., arrythmias). Patients starting on TCAs should have a baseline and routine electrocardiograms. 

In a 6-week double-bhnd, placebo-controlled trial in patients diagnosed with comorbid anxiety and depression, Kramer et al. (1998) described the anxiolytic and antidepressant effects of the NKl antagonist, MK-869. 

Diamond, I.R., Tannock, R., and Schachar, R.J. (1999) Response to methylphenidate in children with ADHD and comorbid anxiety. / Am Acad Child Adolesc Psychiatry 38 402—409. 

Tannock, R., Ickowicz, A., and Schechar, R. (1995) Differential effects of methylphenidate on working memory in ADHD children with and without comorbid anxiety. J Am Acad Child Adolesc Psychiatry 34 886-896. 

Comorbid anxiety has been associated with differential treatment response. This association predicts at times a better response to CBT and TCAs (Hughes et ah, 1990 Brent et ah, 1998). Treatment of comorbid anxiety, which most often precedes depression, is essential because the treatment contributes to improvement and may prevent future depressive episodes (Ko-vacs et ah, 1989 Hayward et ah, 2000). Fortunately, pharmacotherapy and psychotherapy treatments found useful for the treatment of MDD have also been found to be beneficial for treatment of youths with anxiety disorders (Kendall, 1994 RUPP Anxiety Group, 2001). 

If there is a relationship between depression and anxiety, it is not surprising that certain drugs work to treat both. Ample evidence from both humans and animals suggests that the serotonergic system is altered in both types of disorders, and SSRI use is effective in the treatment of both disorders. It should be noted, however, that people who exhibit both disorders tend to be sicker for longer than those with only one disorder, and patients who have comorbid anxiety and depression do not respond as well to SSRI treatments. 

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. 

Comorbid anxiety and depressive features are common in clinical practice, and DSM-IV has included mixed anxiety-depression in its appendix of conditions needing nosological refinement. The presence of comorbid anxiety has prognostic implications. For example, prospective studies of patients with depression have found that the co-occurrence of panic attacks was correlated with a poor outcome (Coryell et al. 1988 van Valkenburg et al. 1984). Some evidence suggests that such patients do better with MAOls. Likewise, patients with depression and obsessive-compulsive disorder may be more resistant to treatment, even with SSRls (Hollander et al. 1991)... 

In human trials, reduced CSF concentrations have been observed among patients with depression. Upon their stratification into high or low levels of comorbid anxiety, the former demonstrated the most dramatic reductions in NPY [Widerlov et al. 1988]. Wahlestedt and colleagues [1993] have employed an innovative methodology to test the validity of this relationship by compromising brain NPY receptors via an antisense oligonucleotide. This knock-out resulted in an escalation of anxiety among test animals. 

Myrick H Brady K (2001). Management of comorbid anxiety and substance use disorders. Psychiatric Annals, 31, 265-71... 

Depressive and anxious symptoms are frequently associated with schizophrenia, but this does not necessarily mean that they fulfill the diagnostic criteria for a comorbid anxiety or affective disorder. Nevertheless, depressed mood, anxious mood, guilt, tension, irritability, and worry frequently accompany schizophrenia. These various symptoms are also prominent features of major depressive disorder, psychotic depression, bipolar disorder, schizoaffective disorder, organic dementias, and childhood... 

Furthermore, a single nucleotide polymorphism of the CB] receptor gene (rs 104935 3) was recendy found to confer an increased risk of antidepressant treatment resistance in female patients with high comorbid anxiety (Domschke... 

Several subtypes of depression require specific treatment strategies that go beyond a simple course of conventional antidepressant therapy (these subtypes include bipolar depression, major depression with psychotic features, seasonal depression, atypical depression, comorbid anxiety disorder, comorbid substance abuse, double depression [major depression... 

Recently, Versiani et al. (1999) conducted a multicenter study involving 157 subjects in whom major depression and comorbid anxiety had been diagnosed. Subjects were randomly assigned to either fluoxetine therapy (20 mg/day) (n = 77) or amitriptyline therapy (50-250 mg/day) (n = 80). Patients were recruited from seven centers in five countries Brazil (n = 52), Mexico (n = 36),... 

Muris P, Steememan P, Merckelbach H, Holdrinet I, Meesters C (1998) Comorbid anxiety symptoms in children with pervasive developmental disorders. J Anxiety Disord 12 387-393. 

I Treatment of comorbid anxiety disorders has not been studied to the same extent as for depression. 

Psychologist with psychiatry support, patient and family evaluation, formulation of comorbidities— anxiety, depression, delirium, counsels patients, family and team, knowledgeable in palliative care and end-of-life decision making... 

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