Diagnostic stability in bipolar disorder in clinical practise as according to ICD-10.

The diagnostic stability of the ICD-10 diagnosis of mania/bipolar disorder has not been investigated in clinical practice. All patients who got a diagnosis of mania/bipolar disorder at least once in a period from 1994 to 2002 at outpatient treatment or at discharge from psychiatric hospitalisation in Denmark were identified in a nationwide register. Totally, 4116 patients got a diagnosis of mania/bipolar disorder at least once; among these, 2315 patients (56.2%) got the diagnosis at the first contact, whereas the remaining patients (43.8%) got the diagnosis at later contacts. Approximately 30% of patients with an initial diagnosis of mania/bipolar disorder eventually changed diagnosis during follow-up. A substantial proportion of patients initially presented with prodromal syndromes such as transient psychosis, reaction to stress/adjustment disorder or mental and behavioural disorder due to psychoactive substance use and got a diagnosis of bipolar disorder later on. Especially younger but also female patients were at increased risk of delay of the diagnosis of bipolar disorder. Only patients from psychiatric settings were included. Clinicians should, especially in younger and female patients, be more observant on manic symptoms in patients who as first glance presents with transient psychosis, reaction to stress/adjustment disorder or with psychoactive substance abuse and follow these patients more closely over time identifying putable hypomanic and manic symptoms as early as possible.