After years of loyal service in the downtown office of a major national corporation, Bonnie Pattridge of Alexandria decided it was time to change jobs. "I never expected my departure to be so difficult," says Pattridge. "After 18 years on the job, I had made some good friends. I knew all the people. I knew what was expected of me. The surroundings were comfortable, and the benefits wonderful. I felt like I was running away from home."

Pattridge isn't alone. Many employes find it "unexpectedly emotionally wrenching" to leave their jobs, says psychologist and career counselor Jacqueline Hornor Plumez. "In many ways," Plumez maintains, "breaking away from a job is just as difficult as breaking away from a marriage. It is totally appropriate to feel confused, frightened and wrenched. Even hard-boiled business leaders feel conflicting emotions when they make a job change . . ."

For many people the job represents everything, says Plumez. Traditional family and communities have eroded, leaving the corporation as possibly the most stable portion in a person's life, representing financial, psychological and emotional security.

"Like home and family, it may not be perfect," says Plumez, "but it is at least familiar."

Job ties are strengthened, too, through interpersonal relations with the boss and with coworkers. According to Plumez, the relationship with the boss is often patterned after a relationship with a parent, for better or worse.

"A good boss," says Plumez, "gets you raises and perks, helps you grow with honest feedback and on-the-job training, nurtures and protects you without being overly permissive, motivates more with praise than criticism, gives you a second chance, and demands and inspires loyalty." This healthy working relationship has a pitfall, however. The employe may be too grateful and too comfortable to leave. And even a good boss is not going to encourage a good employe to jump ship.

Some employes, however, unconsciously seek out "bad" bosses and then stay with them. An employe who has been raised by an overly critical parent, for example, may unconsciously seek a boss who will be quick to criticize.

Another may seek a manipulator or bully if a parent was the same type. Like bad parents, bad bosses often inspire more loyalty than good ones. The employe/child is constantly trying to find a way to please.

How can you tell if you're replaying your childhood in an unhealthy relationship with your boss? Be suspicious, says Plumez, if:

You talk about your boss all the time, or think about him or her obsessively. You're in a managerial position but find yourself doing subservient duties inappropriate to your status.

You find yourself constantly trying to get praise and approval.

You feel frustrated by your boss, but you're not looking for another job.

You look forward to the adrenaline rush associated with an upcoming confrontation between you and your boss.

Relationships with colleagues on the job can be compared to those with siblings, Plumez maintains. Your "brothers and sisters" at work can be rivals or supporters. "A good relationship with your peers at work is one of the best benefits a job can offer, especially in our fast-moving world where friendships are so hard to make and sustain," she says. Friendships can be intense, and the prospect of losing those friendships can inhibit the thought of leaving.

Says Pattridge: "I was very friendly with many of the people I worked with. But after I left, I rarely saw them again. When you leave it's like you've died or never existed because the relationships are based only on the job."

Another reason the office becomes family is that corporations deliberately foster loyalty. Studies show that employe productivity increases when workers know management cares about them and notices what they're doing. Corporations increasingly have implemented the "team approach" to management, and not just during business hours: "Togetherness" is encouraged through such activities as bowling leagues, tennis clinics and conferences. The goal is to "generate a family spirit and keep employes linked to their corporate home." Although this sort of "family feeling" can be manipulative and harmful, "there is much that is good for both employe and employer in this approach," says Plumez. However, she adds, "employes should keep in mind that a company's loyalty is first to its profit and second, to its employes. An employe's first loyalty must be to himself."

How do you know whether to divorce or attempt to strengthen the marriage? Plumez, author of Divorcing a Corporation ($16.95, Villard Books, 1986), suggests a four-step approach, beginning with asking yourself how you feel. Do you feel, for example, like getting out of bed in the morning? Does the prospect of putting in a day on the job get you down? Then perhaps you should go on to step two, which is to identify the benefits a job can offer, decide which are most important to you, and analyze whether they exist in your present job.

Plumez describes 40 possible benefits, including:

Altruism ("My organization benefits people or society and/or makes the world a better place").

*Income ("I am well paid and/or earn enough to have most of the things I want".)

*Location ("Work is near my family, friends or recreational areas"), and

*Pace ("The pace suits me. It is as hectic or as leisurely as I like").

Finally, Plumez recommends reminding yourself of what it was you wanted in the first place, and asking yourself, "What next?"

An employe's decision on whether to stay or leave should also include an analysis of the state of his department, company and industry, and the identification of any "career blocks" -- situations that would be best divorced. They include personality clashes (the higher you are to the top of the pyramid, the more difficult to get around) and corporate culture clash (you're the square peg in the round hole). Plumez urges avoiding the rationalizations ("lies that bind") that could push you into a bad decision, or no decision at all. After gathering and analyzing as much information as possible, the choices should be clear:

1. Quit, but beware: it is usually more difficult and more stressful to find a job when you are unemployed.

2. Look around with every intention of leaving.

3. Look around just to check out other options.

4. Stay and change the problems you face.

5. Stay and put your decisions on hold, hoping your storm cloud will blow over.

"If you've decided to leave," Plumez cautions, "don't burn any bridges, and never tell your friends first. Make sure your boss hears it from you. Plan a resignation speech in which you tell your boss you liked your job and your company, but it was an offer you couldn't refuse. Don't expect your boss to be happy. Unlike real parents whose goal is to prepare their children to go, corporate parents like their children to stay forever. Resist the urge to get things off your chest. Your complaints may come back to haunt you. Beware the counter-offer ('We were just about to give you a raise, a promotion, a company car . . .') Lastly, expect to feel some pain. Saying goodbye is never easy." Vicky Wood is a Washington writer.