testosterone

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Testosterone For Older Men: Major Study Finds Modest Benefits, Mainly Sexual

(Anokarina/Flickr Creative Commons)

(Anokarina/Flickr Creative Commons)

It’s controversial territory, the whole “Low T” arena, and will likely long remain so. But at least some serious data points are beginning to emerge in the form of the Testosterone Trials: a major set of government-funded, double-blind, placebo-controlled studies just published in the New England Journal of Medicine.

The seven linked trials examined the benefits of a year of testosterone gel (vs. placebo gel) in more than 700 men over age 65. It found those benefits to be “moderate,” and mainly for sexual function. Not vitality. Not much for physical functions like walking. A bit for mood. Overall, the Mighty T of the infomercial world is looking more like the modest T.

I spoke with Harvard Medical School’s Prof. Shalender Bhasin, director of the Research Program in Men’s Health: Aging and Metabolism at Brigham and Women’s Hospital and one of the lead researchers on the Testosterone Trials. Our conversation, lightly edited:

How would you sum up these findings?

The main finding of the Testosterone Trials was that testosterone treatment of older men with low testosterone levels has certain benefits, but the size of the benefits was modest. Testosterone improved all aspects of sexual function: It improved sexual activity, sexual desire, erections. Again, the magnitude of the effect was small, much smaller than the effect from previously approved medications for erectile dysfunction such as Viagra and Cialis.

The benefits on physical function and vitality were unclear. There was no improvement in vitality and there was a small improvement in walking ability whose clinical meaningfulness is not clear at the present time. And there was some improvement in mood. The trial was mostly an efficacy trial, so the long-term safety of testosterone still remains unclear. We need larger studies to address the issue of long-term safety, so that the risk-benefit ratio can be appropriately evaluated.

I must say that given all the buzz around testosterone, and the advertisements, the efficacy seems to be kind of underwhelming, doesn’t it? Continue reading

Why Do So Many Women Have Anxiety Disorders? A Hormone Hypothesis

(Stuart Anthony/Flickr)

(Stuart Anthony/Flickr)

Why do so many women suffer from anxiety? Is it something inherent in being female, are we more attuned to our moods? Or is that breath-clenching feeling of impending doom hard-wired?

According to the National Institute of Mental Health, women are 60 percent more likely than men to experience an anxiety disorder over their lifetime. (Obviously, men are not immune: taken together, anxiety disorders are among the most common mental health conditions — they affect about 40 million men and women age 18 and older, or about 18 percent of the U.S. population.)

Mohammed Milad is an associate professor of psychiatry at Harvard Medical School and director of the Behavioral Neuroscience Program at Massachusetts General Hospital. He studies the complex interplay of gender, fear and anxiety. More specifically, he’s looking at how hormones, notably estrogen, might play a role in the fear response and our ability to extinguish fear and anxiety.

I spoke with him about his work. Here, edited, is some of our conversation:

RZ: OK, can you just clearly explain the difference between fear and anxiety? Sometimes it’s a fine line indeed.

MM: I was thinking about taking my kids camping over the summer, and I was reading about bears and potential bear encounters, and considerations for taking cover and putting your food this distance away from your camping site, etc. Anxiety is when you’re camping and you have that heightened awareness — hyper-vigilance  — that’s anxiety, it’s sustained, it’s continuous, but it’s not at the point where it makes you run or look for cover. Fear is when you see the bear; fear is intense, it’s immediate, it’s right there in front of you.

RZ: Thanks for that. But I’m curious, how did you start studying how men and women are different when it comes to fear and anxiety?

MM: When I was in grad school we used to host kids from middle and elementary school…showing our lab to them, showing them the rats, and one kid, maybe 10, 12 years old, asked, are they male or female rats and I said they’re all male rats, and he asked, why, what about the female rats? And I didn’t know the answer, so I went to my mentor and asked, why don’t we study the females? And the answer, simply put, was they’re complicated.

RZ: So the female rats were just too complicated. I get that. But considering far more women than men suffer from anxiety disorders, the fact that you were studying only male rats wasn’t such a great approach, was it?

MM: No, so I think that’s not an acceptable answer now.

RZ: In your experiments on rats and humans, you and your team use Pavlovian conditioning, as in Pavlov’s dogs, who were famously conditioned into drooling every time they heard a bell because they associated that sound with food. So, in these studies you repeatedly showed a blue light on a screen to men and women who would then receive a mild shock, until they came to expect — and fear — a shock every time they saw the blue light. Then, you stopped giving shocks when the blue light came on, to teach the subjects not to fear it. That’s “fear extinction.” And the next day, the men and women were tested to see if they still had a fear response to the blue light.

The results in these studies were all over the place, but most of the variance in fear response was among women in the experiment, right? The men were much more consistent. Why might that be?

MM: That’s what got me into beginning to think about hormones, because what could account for that other than maybe some women that we’re bringing in to the lab were at a particular phase of their menstrual cycle? And when we did that study we found that women who came in when their estrogen is elevated, they had their [fear] extinction capacity much better, in other words, they were able to control their fear, or express much less fear, compared to the women that came in in the early phase of their cycle… when they had low estrogen.

RZ: So just to be clear, high estrogen was linked to better control of fear, and low estrogen meant more potent and longer lasting fear?

MM: Right. Continue reading