Regular Arena Stage theatergoers are opening their programs these days and finding a familiar name missing: Stanley Anderson. He would have been beginning his 18th season, but has gone off to "grab a wild tiger by the tail," recharge his batteries, take on film roles he had eschewed in earlier years, and in general enjoy a midlife crisis brought on by overwork, artistic ennui and time.

"I needed a creative kick in the butt," he said succinctly from his home in Springfield. Describing a hard-thought decision process, Anderson, 50, said that his leaving a job that other actors would die for was not linked to the departure of Arena's founder and producing director Zelda Fichandler, who is leaving at the end of this 40th season for other pastures. (She is continuing to direct the graduate acting program at New York University and will become the artistic director of the Acting Company.)

"He knows the door is open to continue working together," said Fichandler's successor, Douglas C. Wager. "It's hard for me to conceive of never working together again."

By his own accounts, Anderson has appeared in 75 productions at Arena, from his first part as Milady in "The Hostage" in 1972, giving a total of 2,625 performances, half of them on days he was also rehearsing something else. In addition, he performed at several other theaters around town, and did voice-overs to boost the family income. Part of him, he said, was just deeply tired last spring when he made his decision not to return in the fall.

Since then, he has taken a 10-day vacation in the Caribbean, spent some time reading, but also worked in a new medium for him: commercial television and film. He will be seen in February as Ulysses S. Grant in "Son of the Morning Star," on ABC television, and that same month in a feature film called "He Said, She Said," directed by Ken Kwapis and Marisa Silver.

He came to feel the quality of his work at Arena was declining, Anderson said, and as committed as he has been to the ideals of resident theaters, where the notion of stardom is (or should be) supplanted by nurturing the ensemble, he decided it was time to go. "I need to look anew at the world, the work and the reason of what I do," he wrote in an open letter sent to his friends and colleagues at the theater last month.

Wager sees Anderson's departure as an inevitable part of Arena's evolution into middle age. He noted that another departed veteran, Robert Prosky, who left to pursue irresistible television offers such as a continuing part in "Hill Street Blues," is back, rehearsing the part of the Stage Manager in "Our Town," the same role he played in an earlier production of the play. Dorothea Hammond, who appeared in Arena's first production in 1950 ("She Stoops to Conquer"), has also returned to perform in "Our Town," and actress Christina Moore, who left the company a few years ago to abandon acting altogether, is playing Emily.

Meanwhile, the core company has been enlarged to 18, which may reduce the workload for individual actors, and Wager is looking at ways to "loosen our idea of ensemble." In other words, he said, the theater may become more flexible in terms of arranging contracts for a couple of shows rather than requiring a commitment for a whole season.

Anderson said he plans to stay in the Washington area, at least until his wife, Judith, finishes a master's degree in business at George Mason University and his son Derek, a junior, finishes high school. He is enjoying his quasi-normal hours, and for the first time has been able to attend one of his son's football games at West Springfield High School.

"It's always interesting when you're on a mission of discovery," he said of his new life.