Dysthymia

Compared to antipsychotics, there are even fewer studies on the prescribing patterns of antidepressants done in Asian countries. Pi etal. (1985) conducted a survey of psychotropic prescribing practices reported by psychiatrists in 29 medical schools in 9 Asian countries. Daily dose range of tricyclic antidepressants (TCAs) such as amitriptyline, imipramine, and nortriptyline in Asian countries was comparable to the practice in USA. This is despite differences found between Asian and non-Asian populations in the pharmacokinetics of TCAs (Pi et al, 1993). A questionnaire on the practical prescribing approaches in mood disorders administered to 298 Japanese psychiatrists was reported by Oshima et al. (1999). As first-line treatment, the majority of respondents chose newer TCAs or non-TCAs for moderate depression and older TCAs for severe depression. Combination of antidepressants and anxiolytics was preferred in moderate depression, while an antidepressant and antipsychotic combination was common in severe psychotic depression. Surprisingly, sulpiride was the most favored drug for dysthymia. In a naturalistic, prospective follow-up of 95 patients with major depression in Japan, the proportion of patients receiving 125 mg/day or less of imipramine was 69% at one month and 67% at six months (Furukawa et al., 2000). 

Ikemi, Y. and S. Nakagawa, A Psychosomatic Study of Contagious Dermatitis , Kyoshu Journal of Medical Science 13 (1962) 335-50 Imel, Zac E., Melanie B. Malterer, Kevin M. McKay and Bruce E. Wampold, A Meta-Analysis of Psychotherapy and Medication in Unipolar Depression and Dysthymia , Journal of Affective Disorders no (2008) 197-206... 

Rein W. Amisulpride versus imipramine and placebo in dysthymia and major depression. Amisulpride Study Group. J Affective Disord 1997 43(2) 95-103. 

To make the discussion of LCA more concrete, consider an example. Assume we are investigating depression and conjecture three classes indi-viduals with major depression, individuals with dysthymia, and individuals with no depression. After the number of classes has been posited, we can define a mathematical model that links parameters of the latent classes (e.g., base rates) to proportions of cases in each cell of the cross-tabulation. LCA imposes this model on the data set and estimates parameters of the latent classes. This estimation is an iterative process. In the beginning, the investigator provides initial values for each parameter, to get the computation started somewhere. Initial values can be based on a completely unsubstantiated guess. Inaccurate guesses should not prevent LCA from eventually recovering the correct values. An accurate guess, however, would shorten the computation time. 

Trull, Widiger, and Guthrie (1990) examined the latent structure of the DSM-III-R (American Psychiatric Association, 1987) criteria for borderline personality disorder, as well as criteria for dysthymia. Dysthymia is not classified as a personality disorder in the DSM, but it tends to be chronic and is quite similar to personality disorders in this respect. To assist in the interpretation of the borderline personality disorder analyses, dysthymia was... 

Dysthymic Disorder. Dysthymic disorder differs from MDD by being more chronic and less severe. Yet, two issues can cloud the distinction. First, some patients experience double depression in which an episode of major depression is superimposed on dysthymia. This can make it difficult to assess treatment response when the baseline mood is dysthymia instead of a normal euthymic mood. Second, a few patients may experience a chronic major depressive episode, which, like dysthymic disorder, lasts 2 years or more. In contrast to dysthymic patients whose insidious onset of symptoms leaves them unable to say exactly when the depression started, most patients with chronic major depression can tell when their depression began. 

Dysthymic disorder, also called dysthymia, is by definition a chronic illness that lasts two or more years. It consists of persistently depressed mood that is not as severe as major depression. However, double depression can occur in which a major depressive episode is superimposed on a preexisting dysthymia. It is unclear whether double depression is actually two illnesses or a single illness that varies in severity over time. Please refer to Table 3.12 for diagnostic criteria of dysthymic disorder. 

Dysthymia affects 3-6% of Americans in their lifetime. Similar to major depression, women have dysthymic disorder two to three times more often than men. Dysthymia usually begins in childhood or early adulthood. 

The risk factors for dysthymia include a family history of depression and the coexistence of a personality disorder. In addition, dysthymic patients often have major depression, anxiety disorders, or substance abuse disorders as well. 

The key task is distinguishing dysthymia from major depression. The similarity in symptoms and the potential for double depression can make this difficult. Major depression tends to have an episodic course, more neurovegetative symptoms, and more severe disability. On the other hand, dysthymia is a smoldering, unrelenting mood distnrbance. 

For whatever reason, few controlled trials of antidepressants have been performed in the treatment of dysthymic disorder. The limited evidence available, however, suggests that the same classes of antidepressants that effectively treat major depression also treat dysthymia. Reported side effects are similar with the newer agents tolerated better than TCAs. 

Bipolar Syndromes. There are three distinct bipolar syndromes described in DSM-IV BRAD I, BRAD II, and cyclothymic disorder. The most severe subtype, BRAD I, is comprised of episodes of mania and/or depression. BRAD II, in contrast, is defined by episodes of hypomania and/or depression. BRAD II is arguably the most difficult to distinguish from the mood instability of patients with Cluster B personality disorders. Cyclothymic patients fluctuate between phases of hypomania and those of mild depression reminiscent of dysthymia. Although the symptoms of cyclothymia produce significant morbidity and impairment, the disability falls far... 

In trials of hospitalized patients tricyclic antidepressants have generally been more efficacious than selective serotonin reuptake inhibitors (SSRIs). Otherwise there are no overall differences between the drugs in terms of tolerability or efficacy in primary care settings. After reviewing 15 trials it was concluded that drags are effective in the treatment of dysthymia with no differences between and within class of drugs. Tricyclic antidepressants are more likely to cause adverse events and dropouts. As dysthymia is a chronic condition, there remains little information on quality of life and medium or longterm outcome. 

Lima MS, Moncrieff J, Soares BGO. Drugs versus placebo for dysthymia. Cochrane Database Syst Rev 2005. Issue 2. 

Comorbid dysthymia and substance disorder. A total of 642 patients were assessed. Thirty-nine had substance-related disorder and dysthymia (SRD-dysthymia) and 308 had SRD only. Data on past use were collected by a research associate using a questionnaire. The patients with SRD-dysthymia and SRD did not differ with regard to use of alcohol, tobacco, and benzodiazepines. The patients with SRD-dysthymia started caffeine use at an earlier age, had shorter use careers of cocaine, amphetamines, and opiates, and had fewer days of cocaine and cannabis use in the last year. They also had a lower rate of cannabis... 

We have talked about medication as altering personality, taking a person with dysthymia and making her temperamentally hyperthymic, sunny, and social. 

DA, dopamine DD, depressive disorders (major depression and/or dysthymia) DZ, dizygotic twins 5-HT, serotonin p-CIT, iodine-123-labeled 2p-carbomethoxy-3p(iodophenyl) tropane MDD,major depressive disorder MRI, magnetic resonance imaging MZ, monozygotic twins NC, normal controls PC, psychiatric controls PTSD post-traumatic stress disorder rCBF, regional cerebral blood flow SPECT, single photon emission computerized tomography Tc HMPAO, technetium-99m hexamethylpropylene amine oxime. 

Versiani, M., Amrein, R., and Stahl, M. (1997) Moclobemide and imiptamine in chtonic depression (dysthymia) an international double-blind, placebo-controlled trial. International Collaborative Study Gtoup. Int Clin Psychopharmacol 12 183-193. 

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). 

The TCAs, SSRIs, and lithium have been found to be efficacious for the prevention of depressive recurrences in adults (APA, 2000). However, given the noted advantages of the SSRIs and their efficacy in the acute treatment of MDD and dysthymia, this group is considered the first-choice medication for Intervention. 

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