There are considerable data to indicate that psychotic depression is not just a severe form of depression but a distinct form of depression. Mostly in terms of clinical symptoms, course, biology, treatment response and outcomes. However, not every difference is indisputable, there are inconsistencies among studies and these differences might not be strong enough to be used in diagnosis.
The authors of the article suggest to make a new dimension in the next DSM update, a dimension of psychosis with depression. I think that broadening our concepts makes research not any easier. Psychotic depression should be limited to depressions with mood congruent delusions and hallucinations. The inclusion of bipolar psychotic depression and even schizo-affective disorder or strong feelings of guilt has until now hampered the research in the distinction between psychotic depression and nonpsychotic depression.
Differences in clinical symptoms
1. Unusual thought content, increased feelings of guilt and psychomotor disturbances such as agitation and retardation are the most robust differences compared to non psychotic depression for clinical symptoms.
Clinical Course
2. Early onset psychotic depression has been associated with a likely bipolar course.
Cognitive symptoms
3. The greatest cognitive impairments of psychotic depressed patients compared to nonpsychotic major depression were: verbal memory, executive functioning and psychomotor speed. An issue that remains is the medication use of psychotic depressed patients. Usually they are on more different drugs than the nonpsychotic depressed, especially antipsychotic which can influence the test scores.
Biological features
4. Psychotic depressed patients have higher rates of nonsuppression on the dexamethason suppresion test (64%) compared to nonpsychotic depressed patients (41%). The sensitivity and specificity are not high enough to use these tests routinely for diagnosis.
Treatment response
5. ECT is very effective in the acute phase of the treatment of psychotic depressed patients. The data are unclear regarding the duration of this effect.
Issues involved with the distinction between the two types of depression:
1. What is called psychotic depression, hallucinations and delusions, and what kind of delusions, only mood congruent delusions? In Europe the presence of mood congruent delusions and hallucinations justifies the diagnosis psychotic depression. Should we look at dimensions of psychosis instead of a binary division?
2. In the DSM IV psychotic depression is linked to severity of the depression. The relationship between severity and psychotic features is not that strong. This implies a scale for severity and a separate classification for psychotic features.
3. The authors of the article promote a separate dimension for psychotic features with the loss of the distinction between mood congruent and mood incongruent delusions. A development not encouraged by Dr Shock.
4. Additionally more research is needed for the distinction between psychotic depression and schizoaffective disorder.
Article discussed:
Keller J, Schatzberg AF, Maj M. Schizophr Bull. 2007 Jul;33(4):877-85. Epub 2007 Jun 4. Current issues in the classification of psychotic major depression.
Tuesday, October 16, 2007
5 Differences between Psychotic and Nonpsychotic Depression
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Science Daily — Brain imaging has revealed a breakdown in normal patterns of emotional processing that impairs the ability of people with clinical depression to suppress negative emotional states. Efforts by depressed patients to suppress their feelings when viewing emotionally negative images enhanced activity in several brain areas, including the amygdala, known to play a role in generating emotion, according to a report in the August 15 issue of The Journal of Neuroscience.
"Identifying areas in the nervous system that correlate to pathological mood states is one of the pressing questions in mental illness today," says Carol Tamminga, MD, of the University of Texas Southwest Medical Center. Tamminga was not involved in the study.
Tom Johnstone, PhD, of the University of Wisconsin, and colleagues there and at Tufts University studied 21 adults diagnosed with major depressive disorder and 18 healthy subjects of comparable ages. Participants were asked to view a series of emotionally positive and negative images and then indicate their reaction to each one. Four seconds after the presentation of each picture, participants were asked either to increase their emotional response (for example, imagining a loved one experiencing what was depicted in the image), to decrease it, or simply to continue watching the image.
During the test, a functional magnetic resonance imaging scanner detected changes in neural activity. Johnstone and his colleagues also recorded levels of emotional excitement by measuring pupil dilation.
The data showed distinctive patterns of activity in the ventromedial prefrontal cortex (VMPFC) and the right prefrontal cortex (PFC), areas that regulate the emotional output generated from the amygdala. The VMPFC is compromised in depression, likely because of the inappropriate engagement of right PFC circuitry in depressed individuals.
"These findings underscore the importance of emotional regulation deficits in depression," says Johnstone. "They also suggest targets for therapeutic intervention."
According to previous research, normal interaction between the amygdala and the VMPFC may underlie the proper adaptation of levels of the stress hormone cortisol on a daily basis. These levels do not vary as widely in people with major depressive disorder; future research may now be able to clarify the mechanism that underlies this aspect of depression. It could also examine the possibility of using measurements of activity in the amygdala to predict the effectiveness of treatments for depression such as cognitive behavioral therapy.
The work was supported by the National Institute of Mental Health, part of the National Institutes of Health, and Wyeth-Ayerst Pharmaceuticals.
Note: This story has been adapted from material provided by Society for Neuroscience.
Fausto Intilla
www.oloscience.com
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