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| Dysthymia - Recognition and Treatment |
Arun V. Ravindran, MB, MRCPsy, PhD, FRCPC
Professor of Psychiatry, University of Ottawa
Director of Research, Royal Ottawa Hospital |
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In dealing with patients with dysthymia, do they often think that their chronically low mood is just the way they are and they often don't even discuss the possibility that they may have a treatable disorder with their physician?
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Dysthymia can start quite early in life, and often many of these patients do not know or haven't any feeling for euthymia or normal mood state. And it emerges in the adolescent period when they experienced a number of personal difficulties. And as such, it is often difficult for them to understand that they have a treatable kind of depressive disorder. |
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How early in life is early? |
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Recent studies show that it can start as early as preschool and starting school days. And often the commonest time for it to start is in the early to mid-teens. |
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When teens present with dysthymia, what are the main symptoms doctors should be looking for?
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As everyone knows, with every other disorder of mental illness in adolescence, it is often an atypical presentation. They can present with the common kinds of depressive complaints which include school difficulties, behavior problems, sadness, irritability and these unusual kinds of symptoms. |
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So how do you tease out the main differences between major depressive episodes and dysthymia? Are there distinguishing features?
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Dysthymia is a more chronic illness that often starts rather insidiously and often has a fluctuating course. The symptoms are milder than in major depression and vary quite a bit over a period of time. It is also said that the symptoms of dysthymia tend to be more subjective compared to major depression. As opposed to dysthymia, major depressive patients often present with an acute episode of severe, significant symptoms. |
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When you say that symptoms fluctuate, does that mean there are periods of time when patients come out of their chronically depressed mood?
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Not for any extended period of time. The kind of common symptoms that seem to fluctuate are the so-called neurovegetative symptoms - the sleep and appetite disturbances, changes in concentration - these kinds of symptoms seem to fluctuate more often. But the depressed mood and more often the irritability and the anhedonia seem to be a more constant factor in these patients. |
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What about common atypical symptoms found in people with dysthymia. Are there a constellation of atypical symptoms physicians should be looking for?
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We do find atypical symptoms in almost all depressive orders. They are classically described as the reverse neurovegetative symptoms such as increased appetite, weight gain, excessive sleepiness and often a kind of increased sensitivity to interpersonal conflicts. In major depression, they are said to occur in about 20 to 25% of patients. Studies in dysthymia show that these symptoms might be much more common in dysthymic patients - even 50 to 60% of patients with dysthymia may have one or more of these symptoms. |
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In terms of comorbid conditions, are they likely to occur? For example, anxiety often occurs in the depressed patient as well. What about the effect of comorbidity (certainly other mood disorders) in terms of their influence on the course of dysthymia?
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Comorbidity has been found in research studies to be very common in dysthymic patients. It appears the commonest [comorbid disorder] is major depression. The superimposition of major depressive symptoms on somebody with dysthymia is called double depression. Most patients with dysthymia will have a double-depressive episode at some point in their life. In addition, other disorders such as generalized anxiety disorder, also seem to be quite commonly comorbid with this group of patients. |
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What does the presence of double depression do to the way physicians should be thinking about this disease, to be treating it or how should they approach the patient with a superimposed double depression going on?
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I think, essentially, in the acute phase of their treatment, it is to treat major depression first, for a sufficient period of time which could be anywhere from 8 to 10 months, and then to continue treatment, the various psychosocial approaches to treatment for dysthymia and to provide long-term follow-up for these patients. |
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And how should the antidepressant dosing schedules be determined for dysthymic patients?
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It's a frequent misconception that milder forms of depression need only smaller doses of antidepressants. And this is not true. Clinical trials clearly confirm that patients with dysthymia need the same dosage originated for major depressed patients. The average dose needed to treat most of these [dysthymic] patients seems to be very similar to those needed to treat major depressive patients. |
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And should treatment be continued as long as it is continued in major depression?
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There are very few long-term studies of the pharmacologic treatment of dysthymia. Whatever the few studies that have been conducted, plus the anecdotal information from people who often treat these patients suggest, that many patients with dysthymia need long-term treatment, and often this might be life-long. |
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In terms of relapsing, are dysthymic patients as likely to relapse as those with major depression, and if so, is there a time period during which these patients are susceptible to relapse?
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Most studies indicate that the treatment response to antidepressants, particularly the newer generation of drugs, is quite good in dysthymic patients, almost as good as in major depressed patients. Most of these patients remain well on pharmacotherapy. The overall impression is that the majority of them would relapse when the antidepressants are discontinued. So the need for maintenance treatment in dysthymia is even greater than in major depression. |
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And is it full-dose maintenance treatment or are you reducing the dose?
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Overall the impression is that the dose that caused the remission is the one that is needed to maintain improvement, the same as major depression. |
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So you are saying that, in fact, if dysthymic patients wish to remain well, their best option is to stay on long-term full-dose antidepressant therapy more or less indefinitely?
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That seems to be the current findings. And this is of course with the proviso that we do not have any significant long-term or for that matter, too many short-term studies looking at the role of different forms of psychotherapy in these patients. For example, in major depression, it has been suggested that interpersonal psychotherapy could reduce the need for maintenance medications. We do not have any information on that in patients with dysthymia. |
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Is it your impression though, as a clinician, that either cognitive behavioral therapy or interpersonal therapy may be helpful in patients with dysthymia?
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They are likely to add to the therapeutic benefits of antidepressants. It is still unclear whether cognitive behavioral therapy or the forms of psychotherapy on their own are as effective as pharmacotherapy. |
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So you might want to use them in combination but not use psychotherapy as monotherapy?
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We do not have any scientific evidence for that. |
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And in patients with atypical features, which you were suggesting is in up to 50% of dysthymic patients, have there been any different or perhaps better pharmacologic approaches to treating patients with atypical features in their dysthymic disease?
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It's quite clear that these patients respond very well to treatment with the newer serotonergic agents (SSRIs), as well as the older monoamine oxidase inhibitors. And the treatment effect can be quite dramatic. These patients don't appear to do well with psychotherapeutic interventions. So the newer SSRIs and the older MAOIs seem to be the best agents for patients with such atypical symptoms. |
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In general, these patients are still not as impaired as patients with major depressive illness. Sometimes they are carrying on, more or less functioning. Why is it important to pick up and treat dysthymia, since they are relatively functional?
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This is again somewhat of a misconception. Studies have clearly shown that the morbidity of dysthymia is even more than major depression, partly because of the chronicity of the illness. These patients have been shown to seek out medical care repeatedly in different settings because of their chronic depressive illness. The other important need for these patients to be actively treated is their vulnerability to major depression and recurrences. And to reduce such recurrences these patients have to be treated effectively while they have the dysthymia. |
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Is it difficult to convince these dysthymic patients that they do have a treatable disorder and that therapy - indefinite therapy - will very likely result in an improved mood, or is it difficult to convince them to go on such a lifelong program?
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It is somewhat difficult and there are a few pointers that might be helpful for the family physician to know. For example, the frequency of adverse effects isn't much higher in patients with dysthymia compared to major depression. They are not "extra-sensitive" to adverse effects. The second issue is that most of these patients not only improve in their symptomatology but also improve in the quality of life significantly. Thirdly, these patients have to be treated aggressively with the antidepressants, not limiting the doses to just the initial dose and thus minimizing the improvement. |
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