In patients with psychiatric disorders, stability of symptoms has important implications for diagnosis, prognosis, and treatment. Two reviews of symptom stability over the course of psychiatric disorders - bipolar disorder and psychotic disorders, respectively - were published online by the Harvard Review of Psychiatry. The journal is published in the Lippincott portfolio by Wolters Kluwer.
One review reports substantial variation in of diagnostic stability in patients with bipolar disorder, while identifying characteristics associated with lower stability. The second review identifies factors associated with the cumulative impact of the challenging category of "negative symptoms" in patients with psychotic disorders, highlighting the implications for early intervention. The articles will appear in the January/February 2019 print issue of Harvard Review of Psychiatry.
'Room for Improvement' in Diagnostic Stability of Bipolar Disorder
Fanny Cegla-Schvartzman, MD, of the Department of Psychiatry, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain, and colleagues analyzed factors contributing to diagnostic stability over time in patients with bipolar disorder. Of 37 studies identified in a comprehensive research review, six focused mainly on bipolar disorder. Diagnostic stability, defined as "the degree to which a diagnosis remains unchanged during follow-up," is an important means of validating the initial diagnosis.
Although the authors categorize the stability of bipolar disorder as "acceptable" across studies, there remains substantial room for improvement. That finding has substantial clinical implications, given the important differences in treatment for bipolar disorder compared to other disorders like depression and primary psychotic disorders like schizophrenia that share overlapping symptoms. The researchers found that "prospective" consistency was higher than "retrospective" consistency. More than two-thirds of the studies were performed in Europe or North America.
The analysis identified characteristics associated with diagnostic instability, including extreme age, female sex, psychotic symptoms, changes to treatment, substance abuse, and family history of affective (mood) disorders. The researchers conclude, "Additional work is needed to enhance diagnostic stability and to develop tools to quantify the risk of instability."
Negative Symptoms Across Stages of the Psychosis Continuum
Geneviève Sauvé, PhD, of McGill University, Montreal, and colleagues analyzed the course of negative symptoms over the lifetime of patients with psychotic disorders. "Negative symptoms" refer to loss of normal functions, such as anhedonia (decreased ability to experience pleasure), asociality (social withdrawal), avolition (apathy or lack of motivation), alogia (decreased speech), and blunted affect (decreased emotional expression).
The analysis included 47 studies that included patients at different stages along the psychosis continuum. For each negative symptom, prevalence decreased between the "ultra-high risk of developing psychosis" (UHR) and "first episode of psychosis" (FEP) stages, and then increased among "younger patients who have experienced multiple episodes of psychosis" (yMEP).
The findings suggest that negative symptoms are already present in the early stages of the psychosis continuum (UHR and FEP) and that they are most prevalent in the later stage (yMEP). "Early interventions have the potential to reduce the functional limitations associated with negative symptoms," Dr. Sauvé and coauthors write. They emphasize the importance of attending, in particular, to anhedonia, asociality, and avolition - the three most prevalent types of negative symptoms.