Answer
In order to have bipolar disorder, you must have had at least one episode of mania and one episode of depression (one episode of mania is enough to diagnose it, but without depression, it's unipolar mania). A manic episode lasts at least four days, and a depressive episode lasts at least two weeks. There are often periods of normality between the episodes, although it is possible - if rarer - to switch almost immediately between the two extremes. Episodes of both kinds can last weeks or even months. It is possible to have ultradian cycling bipolar disorder, where moods change within a day or even within a few hours, but this is extremely rare, and mood swings of that kind of duration are usually caused by another illness, such as Borderline Personality Disorder. Symptoms of mania are: - Euphoria and/or irritation - Increased energy levels - Decreased need for sleep - Lowered inhibitions - Racing thoughts - Racing speech - Reckless and uncharacteristic behaviour (spending all your money on things you don't need, having sex with strangers, putting yourself in dangerous situations without even noticing they're dangerous) - Starting many different projects (and often failing to finish them) Symptoms of depression are: - Unhappiness - Disturbance of sleep and eating - Lethargy - Low self-esteem (usually self-hatred) - Feelings of guilt - Feelings of hopelessness - Isolation - Suicidal thoughts Episodes of mania and depression can both include psychosis (delusions and/or hallucinations), but mania and depression can and often do occur without the presence of psychosis. In order to diagnose bipolar disorder, the symptoms of mania and depression have to cause significant impairment to your day-to-day life.