Digital archive of theses discussed at the University of Pisa


Thesis etd-05132015-173457

Thesis type
Tesi di specializzazione (5 anni)
Thesis title
Onset polarity and illness course in bipolar I and II disorders: a naturalistic study on 407 outpatients
Course of study
relatore Musetti, Laura
  • manic episode
  • depressive episode
  • bipolar II disorder
  • bipolar I disorder
  • mixed episode
  • polarity onset
Graduation session start date
Release date
Several studies investigating bipolar disorders have shown that polarity of onset can predict differences in symptomatology, course, and prognosis. Frequently, however, research on the topic has examined only bipolar I inpatients and has not included patients with mixed onset. The aim of the present study was to evaluate the clinical characteristics and illness course of a real world sample. This study includes two different part: in the first one, the aim was to examine the clinical characteristics and previous lifetime course of a sample of 407 outpatients (58.7% with bipolar I (BD-I) and 41.3% with bipolar II (BD-II) disorder) according to the different polarity of onset: depressive (DP-o); manic/hypomanic (HM-o); or mixed broadly defined to include agitated depression for BD-II onset (MX-o). In the second part, a subset of the previous sample (266 patients, 153 (57.5%) with BD-I and 113 (42.5%) with BD-II) was monitored prospectively in a follow-up period of at least 48 weeks to evaluate long-term patterns of illness according to the different polarity of onset. As compared with patients in the other two groups: a) DP-o patients (67.3%) were more frequently affected by BD-II and had lower ratings for psychotic symptoms; b) HM-o patients (17%) had a higher rate of family history for psychosis and a lower rate of lifetime suicide attempts; c) patients in the MX-o group (15.7%) more frequently showed substance abuse, had a higher number of mixed recurrences per year and in the BD-II group, MX-o patients more frequently attempted suicide; d) a same polarity recurrence trend was found especially strong in MX-o patients, both in BD-I and in BD-II. This emerged both in retrospective and in prospective course’s analyses. The present study's main limitations are those of retrospective assessment of onset polarity and lack of treatment-impact evaluations in the study of previous illness course. In conclusion, we confirmed clinical expression differences in bipolar disorder in function of polarity of onset in a real world sample. We therefore underscored the importance of carefully considering broadly defined mixed state when examining polarity of onset. Further investigations are required to confirm the present study's results.