Depression itself is considered a unipolar condition, but it is a sign of bipolar disorder also. Suffering in a state of depression can be debilitating to a patient, depending on the severity of the situation.
Some patients are able to snap themselves out of depression with or without the help of medication and a trained medical or mental health professional. Because depression can result in suicide, it is always important that a person suffering from depression be treated, regardless of whether they exhibit a sign of bipolar disorder.
Because signs of depression including fatigue, excessive sleep, irritability, lack of activity, social withdrawal, etc., these indicators are a sign of bipolar disorder, as well.
The difference between unipolar and bipolar is the addition of a state of heightened excitement, considered being a state of mania. This state does not need to coincide directly with the depressive incidents; it could happen days or weeks before or after. It is definitely a sign of bipolar disorder when added to other indicators assigned by or reported to a mental health professional.
Manic episodes are generally accompanied by or include bursts of energy (not needing sleep), significantly more physical activity, or ability when compared to normal functioning, and restlessness. In addition to increased or excessive talking, some of the talking may be incoherent. People may appear to be talking to themselves, when actually they are presuming that everyone is listening to them.
Someone in a manic state may be exhibiting inappropriate behavior, impulsivity, financial irresponsibility, and grandiosity (thinking they rule the world or that they are immortal). Inappropriate behavior may include promiscuity or excessive spending, shopping, or gambling, and drug or alcohol abuse.
An increased awareness or religious affiliation (or rantings) might suggest a sign of bipolar disorder, especially if a person claims to be or know God or another higher power. They may be excitable or hostile, disoriented, or suffering from racing thoughts. Their speech may sound irrational and may echo their disjointed or disoriented thinking.
In extreme cases, someone suffering from bipolarity may see things or people that arent really there (hallucinations) or that someone (or something) is out to get them (paranoid).
Whether suffering from unipolar depression or bipolarity, suicide is a major concern, and while it is not only a sign of bipolar disorder, the rate is thought to be approximately 20 percent of bipolar individuals who do not get treatment. It is presumed that 2.3 million Americans (approximately 1 percent of the population) suffer from an indication of bipolarity.
Image: Jacques Callot. The Temptation of St. Anthony, 1635