In bipolar depression, psychomotor agitation is relatively common and often is associated with other noneuphoric hypomanic symptoms and suicidal ideation. Our goal in this retrospective study was to ascertain the co-occurrence of agitation, bipolar features, and suicidal ideation in unipolar disorder. We retrospectively evaluated 314 inpatients with DSM-IV major depressive disorder (MDD) and no other Axis I diagnosis with the National Institutes of Mental Health (NIMH) Life Chart Method and the Operational Criteria for Psychotic Illness (OPCRIT) checklist to ascertain their symptom profiles across all episodes. Univariate and multivariate comparisons were performed between the subgroups with and without psychomotor agitation (OPCRIT item 23> or =1). Agitated depression (AD, a major depressive episode with psychomotor agitation) was present in 19% of the sample. Compared to nonagitated counterparts, patients with AD were older and had lower educational levels and more dysphoria, insomnia, positive thought disorder, and psychotic manifestations. Hypomanic symptoms other than agitation were relatively uncommon (<10%) and more represented in subjects with AD. No significant differences emerged between AD and control groups with respect to most bipolar validators (gender, familiarity, recurrence). Patients with AD had higher levels of suicidal ideation than non-AD controls; however, such a difference was no longer significant after controlling for psychotic features. Excessive self-reproach, early awakening, diurnal changes, poor appetite, and hypomanic symptoms were independently associated with suicidal thoughts in nonpsychotic MDD. Incomplete information on drug treatment, exclusion of patients with Axis I comorbidity, and tertiary care setting were the most important limitations of the study. Although we failed to support the bipolar nature of MDD-AD by common validators, probably because we used a more heterogeneous definition of agitation compared to similar studies, our data confirm the association of agitation with hypomanic symptoms and suicidal thoughts in major depression, and emphasize the complex phenomenology of AD in an inpatient setting.