Depressive disorders monoamine oxidase inhibitors

Monoamine Oxidase inhibitors (MAOis). Many, though not all, antidepressants are effective treatments for social anxiety disorder. Although they do not provide rapid symptom relief and may even transiently worsen anxiety symptoms during the first 1-2 weeks of treatment, antidepressants have the advantage of treating comorbid depression. 

SRls are currently the most prevalent pharmacological treatment used for panic disorder [see Westenberg and Den Boer, Chapter 24, in this volume], even though tricyclic antidepressants, monoamine oxidase inhibitors [MAOls], and benzodiazepines are also effective. The efficacy of the SRI antidepressants and the observation that initially they may induce deterioration of symptoms [which is usually not the case with treatment of depressed patients with the same medications] raise issues related to the pathobiology of anxiety and its comorbidity with depression. 

It became obvious, however, that psychostimulants were not effective in situations of lowered arousal resulting from mood depression. In the 1950s, antidepressants such as the monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants (TCAs) became recognized as more effective in treating depression. The differentiation between arousal and mood thus became clearer. It is through the action of drugs that sedate and thus reduce anxiety versus those drugs that do not sedate but are anxiolytic that the basic concepts of anxiety have forcibly to be reconsidered. This inevitably led to the need for a reconceptualization of psychotropic modes of action in relation to psychiatric disorders. 

Nolen WA, Haffmans PMJ, Bouvy PF, et al Monoamine oxidase inhibitors in resistant major depression. J Affect Disord 28 189-197, 1993 Nomikos GC, Damsma G, Wenkstern D, et al Chronic desipramine enhances amphetamine-induced increases in interstitial concentrations of dopamine in the nucleus accumbens. Eur J Pharmacol 195 63-73, 1991 Nomikos GC, Damsma D, Wenkstern D, et al Effects of chronic bupropion on interstitial concentrations of dopamine in rat nucleus accumbens and striatum. Neuropsychopharmacology 7 7-14, 1992... 

A collaborative VA study (364) found that the addition of imipramine or a monoamine oxidase inhibitor to CPZ did not benefit chronic psychotic patients any more than CPZ alone. Further, the addition of an amphetamine was slightly harmful. This finding has since been replicated in several studies on apathetic schizophrenic patients (365). A study of chronic ambulatory schizophrenics compared amitriptyline plus perphenazine with perphenazine alone ( 366). While they found the combination slightly better in ameliorating depressive symptoms, it was at the cost of a slight increase in patients thought disorder. 

The depressive phase of manic-depressive disorder often requires concurrent use of an antidepressant drug (see Chapter 30). Tricyclic antidepressant agents have been linked to precipitation of mania, with more rapid cycling of mood swings, although most patients do not show this effect. Selective serotonin reuptake inhibitors are less likely to induce mania but may have limited efficacy. Bupropion has shown some promise but—like tricyclic antidepressants—may induce mania at higher doses. As shown in recent controlled trials, the anticonvulsant lamotrigine is effective for many patients with bipolar depression. For some patients, however, one of the older monoamine oxidase inhibitors may be the antidepressant of choice. Quetiapine and the combination of olanzapine and fluoxetine has been approved for use in bipolar depression. 

Arguably the first modern class of antidepressants, monoamine oxidase inhibitors (MAOIs) were introduced in the 1950s but are now rarely used in clinical practice because of toxicity and potentially lethal food and drug interactions. Their primary use now is in the treatment of depression unresponsive to other antidepressants. However, MAOIs have also been used historically to treat anxiety states, including social anxiety and panic disorder. In addition, selegiline is used for the treatment of Parkinson s disease (see Chapter 28). 

Panic disorder is one of the most prevalent psychiatric disorders in industrialized countries. It is often associated with agoraphobia and has an estimated prevalence of between 1% and 6%. The use of imipramine in the treatment of anxiety by Klein and Fink, and the discovery by William Sargant that monoamine oxidase inhibitors (MAOIs) were effective in the treatment of "atypical depression" over 30 years ago led to the investigation of the efficacy of such treatments in patients with panic disorder. Since that time, such drugs have been shown to attenuate the symptoms of panic in addition to those of phobic avoidance and anticipatory anxiety. As both the... 

The discovery of the antidepressant effect of medications was coincidental to their use for other disorders. Initial work published in 1952 reported that iproniazid (originally used for the treatment of tuberculosis) could elevate mood. Although the use of iproniazid was discontinued due to toxicity, many other additional medications have been tested and approved for the treatment of depression. These include monoamine oxidase inhibitors, tricyclics, selective serotonin reuptake inhibitors, and a heterogeneous class of atypical drugs. 

As we will see later, this type of depressive disorder has been shown to be effectively treated with a particular subtype of antidepressants called monoamine oxidase inhibitors (MAOIs). Recent findings suggest that atypical depressions may also respond to selective serotonin re-uptake inhibitors (SSRIs). 

Monoamine oxidase inhibitors are used to treat depression, atypical depression, bulimia, posttrau-matic stress reactions, obsessive-compulsive disorder, panic attacks, narcolepsy, phobias, hypochondria, anxiety, and many other psychiatric disorders as well as night tremors, parkinsonism, postural hypotension, headache, and aphthous stomatitis. 

The mood and anxiety disorders in their various permutations constitute a major source of personal suffering and impaired ability to engage in productive Avork and interpersonal relationships. Between 5 and 9% of women and between 2 and 3% of men meet the diagnostic criteria for major depression at any time 10-25% of all women suffer major depression sometime in their lives, while 5-10% of men will develop major depressive disorder (American Psychiatric Association, 1994). The anxiety disorders obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), panic disorder, and generalized anxiety disorder (GAD) show lifetime prevalence rates of approximately 2.5%, 7%, 2.5%, and 5% respectively. Between 3 and 13% of individuals in community samples are regarded to meet the diagnostic criteria for social phobia. Mood and anxiety disorders are common comorbidities (American Psychiatric Association, 1994) and the most common antidepressant medications including the serotonin reuptake inhibitors, the mixed serotonin-catecholamine reuptake inhibitors, the tricyclic antidepressants, and the monoamine oxidase inhibitors, are all effective treatments for anxiety and panic attacks. 

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