As men move into their 40s and 50s, the connections among their brain cells actually increase in complexity. This translates into more thinking and feeling. The wonderful part of this is that it allows a man to change--no matter how emotionally limited his parents may have been, he can become more loving, positive, and generative as he ages.

But sometimes these brain changes may affect a man's relationship with his wife or partner, in particular colliding with the irritability that affects many women at the same age. They may also engender feelings and thoughts that are uncomfortable: ruminations about the worth of one's life and occupation, questions about the direction one has taken and the choices one has made, confusion about what to do next, fears about growing older and facing death. These feelings can combine to create what we often call a "midlife crisis," with the potential for depression, affairs, and alcohol or drug addiction.

Confusing and painful as they may be, these feelings, along with the "new freedom" of midlife, also have the potential to transform men's lives into something healthier, more coherent and whole.

Depression: When men are the last to know
A man and his loved ones often do not know he is depressed, because men tend not to like words that imply vulnerability. Instead, a man may experience anhedonia, where he loses his joy, his sense of pleasure, the glad feeling when he sees his wife and children, and the satisfaction of past accomplishment. Irritability and anger are other symptoms of depression in men. Counseling helps, but only if a man avails himself of the confidential therapeutic relationship. Often he equates seeing a mental health expert with "weakness" and will not go.

If the standard treatment of antidepressants and counseling will not work in a specific case, the non-medicinal treatments include daily aerobic exercise, a good diet, and prioritizing duties and obligations to include only those that are absolutely necessary. Time spent outdoors or in contented conversation with family is a source of solace. A new interest or hobby can be a surprisingly effective lateral exit from a depression. Because men may be unwilling to talk about their depression--or may be unaware of it--sometimes it is the wife or partner who alerts the doctor to a man's depression during a clinic visit.

Affairs and the road not taken
For every step forward we take in life, we have to say "no" to something else. Every moment spent studying or working is time not spent on the riverbank in the warm spring sun. But the road not taken does not go away. In Jungian psychology, it is called the Shadow. It gathers strength, and can hit with terrific emotional impact at midlife. The doubts about whether a person made the right choices in his life, the regrets for the love or fun or kindness he did not have or did not take time for, may be idealized in another person, often a younger woman.

Another psychological theory that pertains here is that of the Animus. All women have some masculine aspects to their personalities, and all men have some feminine aspects, but these are often suppressed as people go about their daily roles. As both men and women reach midlife, they seek a wholeness, an amalgamation of their other half. The beloved in an affair may be the mirror of a man's Animus, his own soul reaching out to be complete, and the woman is mistaken for this entity. The Animus can pack a tremendous wallop in the emotional world of the midlife man.

Practically speaking, pornography has changed the way men look at their love lives. When they watch it on the Internet or on adult TV channels, they imagine that they have been missing out on something that is rightfully theirs: perfect bodies, hot sex, multiple partners, etc. Often they do not stop to think that what is shown on the screen is seldom what real people enjoy. This notion of having missed something may cause them to seek an affair.

For men, affairs can seem to "just happen," without their giving much thought to the consequences. The fact that a man has an affair does not always mean that his marriage was unhappy, or that he wanted it to end. Often, the person who had the affair regrets it and wants to be forgiven. This is hard for every family. Counseling with a good marriage counselor who believes in saving the marriage, truthfulness on behalf of the erring spouse, and of course, stopping the affair completely are first steps to save a marriage. Most people do not realize what a tremendous asset a good, long-term marriage is emotionally and materially until it has been lost.

When the son becomes a father
Depression and unease may follow when a man becomes a father. Soon after the birth of his first child, a man may experience emotional pain because of the loss of the relationship with his wife. She must now divide her attention between her husband and the new child, so she will be more tired and less sexually available.

Men may also feel that they are not measuring up as a father, causing an experiential gap between who they want to be and who they are. They may feel shame over these ambivalent feelings toward their children, feelings they may only be able to process later, at midlife, when they have the time and the resources.

Similarly, in his 40s a man may find that his relationship with his own father becomes more ambivalent as his father declines mentally and physically. This experience will be more intense if none of the antagonistic feelings between father and son were ever acknowledged or resolved.

Success and the midlife crisis
Up until his mid-40s, a man may remain emotionally repressed. Then two things happen. First, he acquires enough success that he does not have to devote all of his time to "defending his castle and occupying more land." He also realizes that he wants to receive the payoff for all his work and self-denial--in other words, to be valued and loved, and to get more pleasure out of life. By age 50 he realizes that he will soon become old and that his body and energy may deteriorate before he gets his share of fun out of life. He feels the need to seek gratification before it is too late.

He may never have spoken to his wife about his inner feelings because that would have challenged his concept of masculinity. It is even more difficult for him to share these emerging concerns with her now.

This man needs counseling to sort through his priorities, look back on his life's path and accomplishments, and formulate new goals for the second half of his life. Often he has a profound emotional disconnectedness, and it is essential that he make an effort now to connect emotionally with his family and friends, rather than just working harder. Sometimes he may actually need to be "taught" how to have fun. He may experience depression during this period as well, especially if he has suffered a big loss, such as losing his wife and family through divorce.

Success has a peculiar connection to midlife depression in men. Often a man has achieved in spite of early childhood obstacles, only to feel empty as he gets into his 40s because he never dealt with his early difficult feelings of rejection, shame, or sadness. Sometimes he symbolically reaches out for something he feels he should have had earlier in life.

Alcohol and drug use
Alcohol dependence is common in midlife men who work at difficult, stressful jobs, and reach for alcohol at the end of the day to relax--and to suppress unresolved (and unwanted) feelings. This pattern is a kind of dependence. Ten percent of the population has the genetic predisposition to become alcoholic, and this is one way it starts. Each person has to decide for himself whether or not he is alcoholic and whether his life has become unmanageable. If alcohol has hurt him and those he loves, Alcoholics Anonymous is still the best way to get sobriety. There are now online AA groups that have helped a number of people.

Equally dangerous is prescription drug dependence. Often because of a chronic pain problem, a person can become addicted to narcotics and it may change his personality and his ability to function as a human being. This addiction often requires treatment by a specialist in chemical dependency and pain management.

Don't despair!
The good news is that the brain continues to mature in men as they move into their 50s, so they can add joy and emotional coherence to their lives and their relationships at this critical point. But the emerging feelings they encounter at midlife may also conspire to rock a formerly stable situation. Being aware of the potential for these feelings to create the conditions for depression, affairs, and alcohol or drug dependence is crucial for men making a healthy transition through midlife.

Mayo Clinic-trained internal medicine specialist Kathleen W. Wilson, M.D., is the author of Your Husband's Health: Simplify Your Worry List, from which this column is excerpted. She is also the author of Health for Midlife Women: When You Think You Are Falling Apart, and Brain Maintenance: Preventing Stroke and Delaying Dementia. She was formerly a lieutenant colonel in the medical corps of the U.S. Air Force, and now practices at the Ochsner Clinic in New Orleans. Visit her website at www.boomermedicine.com.