Subsyndromal Mood Symptoms: A Useful Concept for Maintenance Studies of Bipolar Disorder?

Abstract

Objective: To explore the measurement of subsyndromal mood symptoms in relation to studies of maintenance therapy for bipolar disorder. Methods: Literature review of the Medline database using the following selection criteria: (1) ‘bipolar disorder’ plus ‘inter-episode or interepisode or subsyndromal or subclinical or residual or subthreshold’ and (2) ‘bipolar disorder’ plus ‘maintenance or prophylaxis or longitudinal’. Studies of children or adolescents and non-English-language reports were excluded. Results: Of the studies published between 1987 and October 2007, 77 articles about subsyndromal mood symptoms and 257 studies of maintenance therapy agents were found. Only 11 of the 257 studies of maintenance therapy agents discussed subsyndromal mood symptoms. Of the 77 articles, two thirds were published after 2000. Inconsistent definitions of subsyndromal mood symptoms and different evaluation tools and methodologies were used in the studies. Conclusions: There is a need to standardize definitions and validate measuring approaches for subsyndromal mood symptoms. However, when measured in both naturalistic studies and clinical trials, subsyndromal mood symptoms were frequently reported by patients receiving maintenance therapy and were associated with poor functioning. As with other chronic illnesses, knowledge of the patient’s perspective of daily morbidity is important for improving the clinical outcome. Studies of maintenance therapy for bipolar disorder, regardless of the approach, should measure subsyndromal mood symptoms as an additional outcome.

Current prescription pattern of maintenance treatments for bipolar patients in Korea: A focus on the transition from acute treatments

“…Additionally, we simply reviewed the prescriptions between two points without considering the type of bipolar disorder or the nature of the prior episode under the assumption that the recovery state would not differ greatly across the general bipolar population. 26 Thus, we could not determine whether there were different prescriptions according to the types of disorders and the kind and severity of prior episodes. The patients who experienced their prior episodes as mania or hypomania and had the diagnosis of BP-I constituted a large portion of this study sample, so the results may reveal more about maintenance treatment for the bipolar I patients who had prior manic or hypomanic episodes than about any other type of disorder.…”

Brief depressive symptoms in patients with bipolar disorder: Analysis of long-term self-reported data

“…Subsyndromal depressive symptoms are equally impairing in both bipolar I and bipolar II disorder (Judd et al, 2005), and are a predictor of both disability (Bowie et al, 2010;Judd et al, 2005;Simon et al, 2007) and reduced quality of life (Michalak et al, 2008). Furthermore, the total time spent symptomatic may be a better predictor of psychosocial functioning than the total number of episodes, suggesting a cumulative effect from all prior symptoms whether within or outside of an episode (Bauer et al, 2001, Bauer et al, 2010Gitlin et al, 1995;Goldberg and Harrow, 2004). Subsyndromal depressive symptoms are also associated with an increased risk of relapse (Perlis et al, 2006).…”

Altered interhemispheric functional connectivity in remitted bipolar disorder: A Resting State fMRI Study

“…The psychiatric condition of BD commonly characterized by cyclically alternating depressive and manic episodes interspersed with symptomatic remissions. Symptomatic remissions are not free of residual cognitive and/or emotional symptoms 2, 3 . Some of these symptoms actually represent trait characteristics of the illness.…”