Every instance of a manic episode doesn't necessarily point to a definitive diagnosis of manic depression. There are some instances when mania is induced by outside influences. These instances, first identified as early as 1978, are now recognized by the general mental health community.

But it's exactly this secondary mania that makes manic depression so difficult to diagnose. For many individuals with manic depression, they can be a blurring of the causes of the manic episodes.

One of the causes of secondary mania - which would be separate from manic depression - is the use of illegal drugs or alcohol. Should a person be diagnosed with manic depression and also use or abuse these substances, it only complicates the recognition of a manic episode whose origin is truly the disease.

Drugs, though, do more than just confuse and confound the mental health care professional about the origin of the mania itself. It makes the very treatment of manic depression that much more difficult.

Doctors need to take into account if the individual who may be diagnosed with manic depression has any history of drug and alcohol abuse. If he does, then the doctor faces the thorny task of separating mania due to substance abuse from that of the manic depression itself.

The drugs most likely to produce manic episodes mimicking manic depression are cocaine and other stimulants. These are called uppers and in addition to cocaine include amphetamines, methylphenidate and MDMA - known on the street as ecstasy.

Stimulants mimic the manic episode of manic depression by providing the user with a sense of euphoria, increased feelings of power, grandiosity and superiority. Uppers, additionally, give the users increased energy and the decreased need to sleep. In some situations, experts explain, the results seen in drug use closely parallel those manic symptoms of manic depression.

A manic state, prompted not by manic depression but by drug use, will have telling physical signs. These include dilated pupils, increase in blood pressure and heart rate. But to be 100 percent sure of the origin of these mania, a urine test for the presence of drugs needs to be taken.

Moreover, the diagnosis of manic depression may be further complicated following the use of these drugs. Those who use stimulants may experience a 'crash' once the substance has worn off. This state sometimes can't be distinguished from the depressive episode of manic depression.