Duration of untreated illness and suicide in bipolar disorder: a naturalistic study

The aim of this naturalistic study was to evaluate the potential influence of the duration of untreated illness (DUI)—defined as the time elapsed between the occurrence of the first mood episode and the first adequate pharmacological treatment with mood stabilizers—on the clinical course of bipolar disorder (BD). Three hundred and twenty outpatients (n = 320) with a DSM-IV diagnosis of BD—either Type I or Type II—were interviewed; their clinical features were collected and they were naturalistically followed-up for 5 years. At the end of the follow-up observation, the sample was subdivided into two groups: one group with a DUI ≤2 years (n = 65) and another group with a DUI >2 years (n = 255). The main demographic and clinical variables were analyzed and compared between the two subgroups of patients using chi-square tests for dichotomous variables or Mann–Whitney U tests for continuous variables. Patients with a longer DUI showed a higher frequency of suicide attempts (Z = −2.11, P = 0.035), a higher number of suicide attempters (χ² = 4.13, df = 1, P = 0.04), and a longer duration of illness (Z = −6.79, P < 0.0001) when compared to patients with a shorter DUI. Moreover, patients with a longer DUI had a depressive first episode more frequently than patients with a shorter DUI (χ² = 11.28, df = 2, P = 0.004). A further analysis performed dividing the total sample into two subgroups on the basis of a DUI of 6 years (corresponding to the median value of the DUI in the study sample) confirmed prior findings. Results indicate a potential association between a longer DUI and a worse outcome in BD, particularly in terms of suicidality, and confirm the clinical relevance of early diagnosis and pharmacological intervention with mood stabilizers in BD.