For Alzheimer's, the old Dickensian paradox holds: we are in the best of times and the worst.

Times are bad because there is no effective way to treat or prevent Alzheimer's, and global rates of the disease are going to double by 2030 and reach 135 million by mid-century. Families are financially and emotionally devastated by the disease, and national budgets are becoming overwhelmed by the disease's extraordinary costs.

And even though Alzheimer's is a greater burden than cancer, diabetes, and other age-related non-communicable diseases, only rarely does Alzheimer's receive adequate attention.

But times are also good. The fight against Alzheimer's is gaining an impressive set of new allies. Margaret Chan, the Director-General of the World Health Organization, has joined the effort. And British Prime Minister David Cameron has made a definitive proclamation, stating that Alzheimer's threatens global health and economics as much as HIV/AIDS. And by putting the G8 right in the mix, Cameron joins President Obama at the front of the global "fight-back" against Alzheimer's.

And it's not just politicians who are taking a stand. One of Hollywood's bawdier comedians has recently testified before a Senate committee, and he took them to task for their inaction against Alzheimer's. Seth Rogen -- through a refreshing blend of humor, empathy, and high-stakes policy criticism -- has become the newest, most-tweeted Alzheimer's advocate. His funny, but chiding testimony pointed fingers at Congress for not paying attention to the disease, and it generated perhaps more social media buzz around the disease than anything previously in Alzheimer's history. At last, the younger generation is on board.

But with all this momentum, and against all these challenges, the big question looms: Where do we go from here?

The answer, it turns out, is as simple as it is elusive: It depends.

Editor's note: this blog originally appeared on Huffington Post 50 

There are some possibilities with medicines. Though Alzheimer's drug development is puttering along because of complex biology and hardheaded regulation, a few companies have promising late-stage drug candidates for people with mild cognitive impairment. But for people with Alzheimer's, the prospects remain less promising.

There are also possibilities of prevention. Prevention trials are underway in populations that have no symptoms but do have a high likelihood of contracting disease symptoms.

And there are also possibilities of reversal. Stem cell therapies are being developed that aim to stop or reverse the effects of brain impairment. These therapies are currently in animal trials, but they aim to begin human trials in the next 5-7 years.

And then there are also the possibilities with technology. One of the best examples comes from Qualcomm. The semiconductor company is sponsoring a Tricorder X Prize for the development of a new generation of hand-held mobile devices that can diagnose 15 distinct disease conditions. This Prize is a revealing representation of where we may be headed: semiconductors and digital technologies are no longer just gee-whiz stuff. Tech and healthcare are merging in fascinating, disruptive ways.

All of this is "lean forward" stuff, but that's the reality of the situation: our hopes in recent years have been dashed by late-stage failures, so we wait, and hope. But like a jilted lover, we can't truly fall in love without further dating.

That's the message for Silicon Valley: keep dating, and get more fully on board. Unleash your powers and join the global fight against beat Alzheimer's.

It is only with Silicon Valley's leadership that the "digitization of medicine" will come to be. As physician-cum-thought-leaders Robin Cook and Eric Topol have put it, digital medicine will be the breakthrough of all breakthroughs, and it will enable "treatment to be tailored to each person." As Cook and Topol see it, mobile sensing and diagnostic devices, like those being catalyzed by Qualcomm, must be one of the forces most responsible for this burgeoning transformation.

Yet these mobile devices are, so far, focused on the neck-down -- and not on the neck-up. While there may be apps that promise to detect some cognitive decline, there is no hand-held medical device being designed or tested to diagnose Alzheimer's.

But, again, there are promises on the horizon. Quite recently, it was announced that anew kind of blood test was being developed that could detect Alzheimer's. Such a development would completely change the diagnostic game, especially if it were integrated into a handheld device. And if such a test were coupled with a successful "prevention drug" for Alzheimer's, we would have on our hands, quite literally, both the capability to test for Alzheimer's and a medicine to prevent it.

Finally, there are also possibilities that can always fly in from left field. Take DARPA's development of a "memory prostheses" for troops with traumatic brain injury. Drawing on DARPA's insights, could an Alzheimer's "memory prosthesis" be developed to mitigate symptoms once the disease has progressed beyond stages of prevention?

With so much potential for Alzheimer's developments -- coming from both within established channels and from new sources of innovation -- one thing should be clear: we are at a turning point. And if the "digitization of medicine" takes off as many predict it will, let's hope that Alzheimer's stays right in its crosshairs.

Seth Rogen suggested before the Senate committee that Alzheimer's is still unfairly stigmatized and that this stigma keeps us from making progress against a devastating disease that touches tens of millions of families around the world. He's right.

Hollywood is 350 miles from Silicon Valley. Let's hope Mr. Rogen's message makes it up the coast.