A recent public service spot on TV shows three men on a construction site eating lunch. Two of the men watch the third take a psychotropic medication, a category of medication utilized for depression, bi-polar disorder and other mood disorders. Both look at each other and then to the third man as if to say, "What's the deal? Why would you do something like that? Are you off your rocker, man?"

The third man looks at one of the other men and queries, "You have diabetes, don't you?" "Yes," comes back the answer. And to the other he says, "And you have a heart condition, don't you?" "Yes," again comes back the answer. "Well," he challenges, "you take medication, don't you? What's the difference?" The other two men look at each other in a somewhat bewildered way as if to suggest that the third man's point is dawning on them - "Yes, what is the difference? Maybe there really isn't any."The third man is referring to the fact that anyone can have a biological condition, or a genetic cross to bear, whether that cross be depression, diabetes, hypertension, glaucoma or any other physical condition.

Under such circumstances, people have one of two choices: one choice is that of not taking medication and consequently incurring the symptoms and the physical penalties that accrue when the body lacks what it needs to survive or thrive. This choice may lead to an early death or to substantially reduced quality of life - and even acute suffering - for years.

Or a second choice is to treat the physical condition and substantially neutralize or counteract negative effects on one's body. This choice brings with it the probability of a fairly normal life, free of most - if not all - consequences that occur when the needs of the physical body are neglected. And this choice usually ensures that the illness will not rapidly progress until its ravages cannot be contained with medication.

In any case, the choice to take appropriate medication for any physical condition, be it depression, bipolar disorder, diabetes, hypertension or a hundred other physical - and often genetic - conditions, must always be weighed against the physical and emotional penalties one accrues in not taking such medication. And those penalties may be many and harsh.

Each of the preceding disorders or physical conditions affect different parts of the body. For depression or bipolar disorder, it is the brain that suffers because of an imbalance in the three major neurotransmitters or chemicals , as well as many other minor ones. The brain sometimes produces too much of a chemical or not enough. Or the brain chemicals may be out of kilter in other, more complicated ways.

But if adverse chemical conditions are present in the brain, they have often been there since the sperm hit the egg in embryonic form. Such conditions are poised - as are other physical conditions that beset the body - to come forth in their own good time, to evolve in different forms, to have different masks, to present varying predominant symptoms and to proceed in greater intensity as persons - during their life span - go through their own physical and emotional evolution and as they get older.

The development of such illnesses is also conditioned by a tangle of not only heredity and biology but also environment and intensity of stress.

Depression and bipolar disorders fall along a spectrum in terms of intensity, frequency, duration and number of symptoms; and for bipolar disorders, cycling of moods is an important dimension in diagnosis. The entity of depression itself - major or not - may not necessarily be biological in origin but can be caused by too many stresses hitting a person too many times, too many ways, too intensely and over too long a period of time.

In such instances, the inordinately acute but long-term stress a person experiences overwhelms the brain's capacity to function or to process information, and the chemicals in the brain go awry in ways similar to biological depression. If such depression is lingering and does not respond quickly to therapy or other proactive interventions, taking a new-generation antidepressant represents a sound decision.

Medication should almost immediately alleviate the depression, which otherwise - subject to the same intense and major stresses - may linger for months or, in the worst-case scenario, even years. And after a period of months, the brain - essentially given "time off" to heal - recovers, and medication is no longer necessary.

Medically treating lingering situational depression may be helpful for a number of reasons. Able to almost immediately function better, an afflicted person's performance and ability to cope picks up across the board, which may potentially alleviate acute stress on children and other family members.

Also, the ability to think much more clearly enables a person to work through problems and to take decisive action needed to alleviate stresses interactive with problems.

In addition - now able to organize, concentrate and to commit to goals - people can implement actions that increase physical and emotional healing, such as committing to daily exercise, eating per sound nutritional standards, meeting emotional needs and structuring their lives to attend to priorities. Finally, neutralizing a depression also aids in any talk therapy, enabling a person to work more efficiently in resolving problems and decreasing the need for, and time in, a therapeutic situation.

Next week: Depression and bi-polar disorder - the particulars.

JoAnn Larsen is a therapist in private practice in Salt Lake City.