Differences between bipolar disorder types 1 and 2

Ross Baldessarini, MD

McLean Hospital – Faculty
Baldessarini_Ross poster

Scientific Abstract

Objective: To compare characteristics of patients with type II (BD-2) vs. I (BD-1) DSM-5 bipolar disorders. 

Methods: We compared descriptive, psychopathological, and treatment characteristics of 1377 consenting, consecutive adult BD patient-subjects, with standard bivariate statistical methods. 

Results: Many factors differed between the diagnostic types.  With BD-2 these included: descriptors (more familial affective disorder, older at onset, diagnosis and first-treatment, more education, employment and higher socioeconomic status, more marriage and children, and less obesity); morbidity (more co-occurring medical diagnoses, less drug abuse and smoking, more initial depression and less [hypo]mania or psychosis, longer depressive episodes, higher intake depression and anxiety ratings, less mood-switching with antidepressants, less seasonal mood-change, greater %-time depressed and less time [hypo]manic, fewer hospitalizations, more predominant depressive polarity, depression before [hypo]mania or euthymic intervals (D-M-I) course-pattern, and less violent suicidal behavior); and treatment (less use of lithium or antipsychotics, more antidepressant and benzodiazepine treatment). 

Conclusions: BD-1 and BD-2 show many differences.  As expected, BD-2 was characterized by predominance of depression with some hypomania and mixed-states but neither mania nor psychosis.  BD-2 subjects had higher socioeconomic and functional status but also high levels of long-term morbidity and risk of suicide.  Accordingly, BD-2 is dissimilar to, but not necessarily less severe than BD-1.

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research Areas


Ross Baldessarini, MD, Alessandro Miola, MD, Marco Pinna, MD, Martina Contu, Leonardo Tondo, MD, MS

Principal Investigator

Ross Baldessarini, MD