In addition to specific depressive or manic symptoms, more general symptoms also occur during the prodrome of both bipolar disorder type I and bipolar disorder type II, according to a report in the Journal of Affective Disorders.
For example, patients with both bipolar disorders frequently reported mood lability and disturbed diurnal rhythm during the months leading up to their first depressive or manic episode, said Dr. Eike Zeschel of Ruhr University, Bochum (Germany), and associates.
Even though most patients with bipolar disorder report having prodromal symptoms and signs, thus far those reported in the literature "appear neither sufficiently characteristic nor specific to allow the construction of empirically derived assessment instruments and symptom thresholds, or to suggest precise guidelines for the management of prodromal illness manifestations."
To further characterize the prodrome of bipolar disorder, Dr. Zeschel and colleagues performed structured interviews, which included administering the Bipolar Prodrome Symptom Scale–Retrospective and the Semi-Structured Interview for Mood Swings, with 42 bipolar participants who were treated at three university hospitals in Germany. They assessed 39 symptoms and signs that emerged or worsened before the first manic or depressive episode.
The mean age of these study subjects was 35 years, and 25 (approximately 60%) of them were women. A total of 27 patients had bipolar disorder type I and 15 had bipolar disorder type II.
The mean age at illness onset was 30 years (range, 18-58 years). The mean interval between the initial diagnosis of bipolar disorder and the study interview was 5-6 years. This means that all the study subjects were recalling experiences from several years earlier when responding to questions about their prodromal symptoms, the researchers noted.
All but one patient were taking psychotropic medication at the time of the interview. In addition, 9 patients had comorbid psychiatric problems such as substance use disorder or personality disorder, and 16 had physical comorbidities such as hypertension and thyroid dysfunction.
Overall, every patient with type I bipolar disorder and all but one patient with type II reported having at least one prodromal symptom just prior to their first episode.
The predepressive prodrome lasted significantly longer (4.1 months) than did the premanic prodrome (1.3 months). However, the frequency and severity of symptoms were similar between the two types of bipolar disorder.
The most frequently reported prodromal symptoms leading up to the first depressive episode were depressed mood, reduced vitality, physical exhaustion, tiredness, and social isolation. In contrast, the most frequently reported prodromal symptoms leading up to the first manic episode were feeling extremely energetic, physical agitation, talkativeness, racing thoughts, and low requirement for sleep.
However, general symptoms such as labile mood and disrupted sleep patterns also occurred frequently in both groups of patients. These "might be indicators for early recognition of bipolar disorder," Dr. Zeschel and associates said (J. Affect. Disord. 2013;151:551-60).
The first prodromal symptoms to appear in both patient groups were irritability, impatience, social isolation, weight gain, tiredness, and suspiciousness.
These findings highlight "the necessity to inquire about the patients’ entire psychopathological symptom ‘package’ and not only about specific affective symptoms when suspecting that they may be developing bipolar disorder," they said.
In general, prodromal symptoms showed "a progressive, accelerating course toward a full-blown mood episode." Symptoms "became more prevalent and more specific to the respective affective phase the closer the patients got to their mood episode," the investigators added.
Psychosis-like symptoms occurred significantly more often during a depressive than during a manic prodrome.
Dr. Zeschel and associates cited limitations. First, patients with both bipolar I and bipolar II were included in the study to get a larger sample size. Future studies are needed to focus on the separate subtypes of bipolar, they suggested. In addition, prodromal frequency and patterns might have been underreported "based on the assumption that patients are more likely to forget, minimize, or underreport symptoms," they wrote.
Nevertheless, these findings "support current approaches of early recognition programs for [bipolar disorder]," Dr. Zeschel and associates said.
More retrospective studies with larger patient populations would further clarify prodromal symptoms, and prospective studies "will be crucial to develop targeted early identification and intervention programs," they said.
Dr. Zeschel reported no conflicts of interest; Dr. Zeschel’s associates reported numerous ties to industry sources.