• AGE AT ONSET
• BIPOLAR DISORDER
• COMORBIDITY
• GERIATIC PATIENTS
• PHARMACOLOGICAL INTERACTIONS

Background: Nevertheless the diagnosis of mania in the geriatric population is not rare, currently, the systematic literature focusing on this heterogeneous condition is small and controversial also because a standard age for the term geriatric and a standard cut-off to determine “early” and “late onset” bipolar disorder have not yet been determined. Elderly mania represents a challenge even for expert clinicians because of the frequency of concomitant somatic and cerebral organic pathology.
Aim: Firstly, we aimed at exploring if the age at onset of bipolar illness is associated to specific clinical features of mania in elderly bipolar inpatients; secondly, at testing the hypothesis that bipolar elderly patients hospitalized for a manic episode with early onset of bipolar disorder have a more severe burden of illness than those with late onset and possibly at identifying a more severe bipolar patients subgroup.
Methods: A retrospective chart review was conducted in 54 bipolar maniac patients older than 64 years old. In the first-session analysis we divided the sample into two subgroups using as a criterion age at onset 50 years. Early onset (EO) group was made by 29 patients and late onset (LO) group was made by 25 patients. Demographic, clinical features and pharmacological treatment at hospitalization and at discharge were recorded and neuroradiological exams were also performed. Young Mania rating Scale (YMRS) was also administered. The same variables were explored splitting the sample in two groups using the cut-off of 60 years (second-session-analysis). Finally, we performed a linear multiple regression analysis using the age at onset of bipolar disorder as dependent variable to determine whether some of the meaningful clinical features associated to a higher severity of illness correlate with an earlier onset of bipolar disorder (third-session-analysis).
Results: When using 50 years as a criterion of age at onset no statistical differences emerged among the two groups regarding the explored variables except for: higher score at the item irritability at YMRS at TO in the EO (mean 4.5; SD 2.0) group compared to LO group (mean 3.36; SD 1.7) (t 2.2173; p 0.0310); prevalence of cardiopathy (13.8% EO vs 56.0% LO; χ2 6.4128; p 0.019) and Beta-blockers prescription (3.5% EO vs 28.0% LO; χ2 6.4128; p 0.019) in the LO group.
Dividing the sample by using 60 years old as a criterion of age at onset we found few statistically significant differences between the two group. More than half of the patients with onset after 60 (OA60) had a manic onset compared with about 17% of patients with age at onset before 60 (OB60) (χ2 6.3844; p 0.034).
Interestingly, the OB60 presented a higher number of total psychiatric comorbidity (mean 0.7; SD 0.7) compared to OA60 (mean 0.3; SD 0.4) (t 2.1260; p 0.0383).
OA60, analogously to what found in the comparison using the 50 years cut-off, presented more frequently cardiopathy (OB60 23.7% vs OA60 56.3%; χ2 5.3734; p 0.020).
With the multiple linear regression we found: a positive correlation between age at onset and cognitive alterations (p 0.011); no correlations between age at onset and neuroradiological findings/neurologic disorders. Number of psychiatric drugs (p 0.027) and number of somatic conditions (p 0.046) were inversely correlated to age at onset.
Conclusion: Our study revealed that elderly manic patients with late onset had higher incidence of cognitive symptoms in the acute stage. Conversely, elderly manic patients with early onset, independently from their length of illness presented more somatic conditions and were prescribed more psychiatric drugs. Age at onset of bipolar disorder in bipolar manic patients may identify a group of patients at higher risk for more severe pharmacodynamic and pharmacokinetic interactions.