Dear Doctor: My husband has seemed really down since the birth of our son six months ago. We're both being run ragged, and very proud of our son, but my husband seems less happy than I had hoped he would be. Could he be suffering from postpartum depression? If so, how? I'm the one with the hormonal onslaught!

Dear Reader: "Running ragged" is a good description of parents in the first year of a child's life. Many have described it as going into a tunnel. Metaphorically, it can get mighty dark in there. Parents and their new child grope around to find some sense of normalcy, when every day brings a new change or a new obstacle. Adding to these challenges for women is the drop in the hormones estrogen, progesterone and oxytocin after pregnancy, which can trigger mood fluctuations and postpartum depression. Men don't have that same hormonal drop, but that doesn't mean they don't experience changes.

Studies in mammalian fathers, including humans, who take care of newborns have shown drops in their testosterone levels after birth and a rise in their levels of prolactin, a hormone typically linked to a female's ability to produce milk. Evolutionarily, it makes sense that men who are helping to take care of children should have a drop in testosterone. Testosterone is needed for procreation, which should be the last thing on a dad's mind when he's taking care of a child. In fact, studies in multiple societies have found that the more hours a father invests in childcare, the lower his testosterone level will be.

A recent study in the journal Hormones and Behavior attempted to evaluate levels of testosterone and postpartum male depression in 149 low-income males (30 percent had household incomes below the poverty line). Fathers and mothers were assessed for postpartum depression, parenting stress, relationship satisfaction and intimate partner aggression. These assessments were performed one to three months after birth, six to nine months after birth and 12 to 16 months after birth. Also, at nine months after birth, the fathers underwent salivary testosterone testing.

Lower testosterone in fathers at nine months after birth correlated with increased depressive symptoms at that time, but not when depression was tested again at 15 months. Men with depressive symptoms at nine months also reported increasing parenting stress six months later. Interestingly, though, lower testosterone in the father at nine months was associated with less postpartum depressive symptoms in the female partner at nine months and 15 months.

The men with higher testosterone levels had decreased depressive symptoms at one to three months after birth, but this did not hold true at the six-to-nine month and 12-to-16 month intervals. However, the female partners of the men with higher testosterone levels reported more depressive symptoms and more feelings of aggression from their partner at the six-to-nine and 12-to-16 month intervals. Also, men with higher testosterone levels had increased parenting stress at 15 months.

The findings are complex, but they show that hormone levels do indeed fluctuate in men, affecting their psyche, their outlook and their relationships. Specifically, higher and lower levels of testosterone are linked to psychological changes in both parents.

As you know, being a parent isn't easy. Aside from the hormonal changes, parents of both genders can face financial pressures, sleep deprivation and the realization that life has changed dramatically. Each person processes and adjusts differently. My advice: Keep communicating. Your son will benefit from it.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I had shingles about 10 years ago, just after I turned 50, and it was just as difficult and painful as everyone says. Now I hear that it's possible I can get it again. Is this really true? Should I get the vaccine?

Dear Reader: Unfortunately, it's true that having had shingles once does not bestow immunity. While a second bout is rare -- it's estimated that as few as 1 percent of people who have had shingles get it again within the first three years -- the odds do increase over time. According to the Centers for Disease Control and Prevention, 7 percent of people who have had shingles will go on to have another bout within seven years.

For those who don't know, shingles is a nasty rash that can occur in people who have previously had chicken pox. It happens when the varicella zoster virus, which causes chicken pox, emerges from its dormant state and travels along nerve fibers to the skin. In addition to a blistering rash, shingles can be accompanied by nerve and muscle pain and extreme skin sensitivity. Although you can get shingles at any age, half of all cases occur in people 60 and older.

Someone with active shingles can't spread the rash, but because the liquid in the blisters contains the virus, they can spread chicken pox. That makes it vital to not have physical contact with anyone who has not had or has not been vaccinated for chicken pox while you have shingles. As though the pain, itching and burning of the rash weren't bad enough, people with shingles also run the risk of being left with ongoing nerve pain, a condition known as post-herpetic neuralgia.

While this all sounds quite grim, there is some encouraging news. A new shingles vaccine called Shingrix has been released. In clinical trials with over 38,000 people, it has shown to be 90 percent effective in preventing shingles in people between 50 and 80 years old, according to clinical data from the CDC. However, when the age groups between 50 and 80 are analyzed separately, efficacy varies.

The two-dose vaccine got a preliminary nod from the CDC in October. An advisory committee recommended that Shingrix should be administered in place of an older existing vaccine, called Zostavax. Given in a single dose, Zostavax isn't as effective as the newer vaccine. It offers a 51 percent reduction in shingles, and reduces nerve pain by about 65 percent.

The CDC's advisory committee is recommending that individuals 50 and older be vaccinated with Shingrix. The committee is also urging that anyone who has already been vaccinated with the older, single-dose vaccine now also receive the new one. The vote in favor of the new vaccine was not unanimous, however. In fact, it was nearly a split decision, with eight members voting for the new guidelines, and seven voting against. A final recommendation from the CDC regarding Shingrix could come as soon as next year.

In the meantime, we would suggest you discuss these developments with your doctor. If you are a candidate for either the new or old vaccines, they may help prevent a recurrence of a painful and challenging condition.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Now that I'm in my 60s, with an enlarged prostate, I'm noticing ads and solicitations offering the latest and greatest herbal remedies for my prostate health, such as saw palmetto. Do any of these remedies actually work?

Dear Reader: Undoubtedly, you want relief. The much-maligned prostate gland is necessary throughout a man's life for sexual function, but it's generally discussed only as a man ages and it becomes cancerous or, in your case, enlarged. Because the prostate sits at the lower end of the bladder and surrounds the urethra, this enlargement can cause obstruction of urinary flow. This, in turn, causes a slow urinary stream, hesitancy and straining with urination, frequent urination and the need to get up multiple times during the night to urinate.

Many over-the-counter prostate products contain saw palmetto (Serenoa repens), a species of dwarf palm tree that bears fruit. Extracts from the fruit have been used in supplements as far back as ancient Egyptian times to help men with urinary symptoms, and they may work for many possible reasons. For starters, they can inhibit the formation of the prostate-stimulation hormone, dihydrotestosterone, in a way similar to prescription medications Avodart and Proscar. Saw palmetto also may relax the muscles at the lower portion of the bladder, allowing the urine to empty more completely, and may shrink prostate size due to an anti-inflammatory effect.

A 1998 review in the Journal of the American Medical Association analyzed 18 saw palmetto studies involving 2,939 men. The average length of the studies was nine weeks. Among men who took the supplement, the authors found a decrease in urinary frequency and nighttime awakening to urinate, plus an improvement in urine flow. The results were similar to those for the prostate drug Proscar.

But results of a 2012 review using data from different medical sources were more mixed. In 32 studies involving 5,076 men using either saw palmetto or a placebo, some studies showed benefit, but not all. The average length of these studies was 29 weeks. The authors concluded that, in general, saw palmetto did not show a significant degree of benefit. Note, however, that one proprietary blend, called Permixon, has shown benefit in multiple European studies.

My opinion is that saw palmetto likely does have a mild beneficial effect. The biggest side effect can be a decrease in libido.

Now let's take look at other supplements touted for prostate health.

Stinging nettle (Urtica dioica) has been shown to shrink prostate size in rats, and a 2005 placebo-controlled study of 620 men in Iran linked the herb to an improvement of urinary flow and less urine retention in the bladder. These results have not been replicated in other studies, however.

Pumpkin seed oil has shown benefit in rats, but no good studies have been done in humans.

Selenium -- at higher levels in the bloodstream -- has been associated with a lower risk of prostate cancer. However, no good studies of selenium and prostate enlargement are available.

Ginger may decrease prostate size, but -- again -- no good studies have shown that it reduces symptoms in humans.

Lastly, vitamin E, which had been used in many supplements, has been linked to an increase in the risk of prostate cancer.

The upshot? Although many supplements and vitamins may benefit the prostate, they can have side effects and need to be studied further.