Pfizer, the world's third largest drug maker, has announced it is ending research to discover new medications for Alzheimer's and Parkinson's disease.

The move, which will eliminate hundreds of research positions across the pharmaceutical giant's roster, casts an even darker shadow outside the company – dashing the hopes of millions affected by neurological disorders, whose dreams of finding a treatment just got that much more desperate.

"As a result of a recent comprehensive review, we have made the decision to end our neuroscience discovery and early development efforts and re-allocate [spending] to those areas where we have strong scientific leadership and that will allow us to provide the greatest impact for patients," the company said in a statement to NPR.

Job reductions primarily in Massachusetts and Connecticut are expected to occur across the next several months, although the company is continuing research into rare neurological diseases, and plans to launch a venture fund committed to neuroscience.

To many, though, those gestures won't replace the loss of some 300 neuroscientists and associated staff in an organisation that bills itself as "the world's largest research-based pharmaceutical company".

"Any decision impacting colleagues is difficult," the company's statement reads.

"[H]owever, we believe this will best position the company to bring meaningful new therapies to market, and will bring the most value for shareholders and patients."

Of course, value for shareholders is one thing; but for patients, especially those affected by neurological diseases (and their families), it's quite another, as critics of Pfizer's new direction are eager to make clear.

"[W]ith no new drug for dementia in the last 15 years, this will come as a heavy blow to the estimated 46.8 million people currently living with the condition across the globe," says the head of research at the UK's Alzheimer's Society, James Pickett.

"Every three seconds someone in the world develops dementia and, with this number set to rise, there has never been a more important time for such life-saving research."

That's especially so since the best, mostly ineffective medications we have for conditions like Alzheimer's are in fact the products of research from decades ago.

While there are strong hopes they can be improved upon – and treatments for Parkinson's and other neurological conditions too – until more research is done, a hoped-for, effective replacement won't materialise.

"The current medication for Alzheimer's disease is approved, essentially, because it's better than nothing. There's nothing else at the moment," neuroscientist Joseph Jebelli told NPR last week.

"These drugs were pioneered in the '70s and '80s and they treat the symptoms, as opposed to the underlying biology."

Of course, one company announcing the closure of one wing of medical research doesn't signal the end of other scientists working in that field – but in light of Pfizer's dismaying decision, some commentators are wondering what this means for the rest of the big pharma landscape in terms of neuroscience research.

"It's really alarming to see such a large pharmaceutical company deciding to abandon research into the brain and central nervous system," chief scientific officer at the Parkinson's Foundation, James Beck, told the Los Angeles Times.

"[H]aving Pfizer exit does not augur well for what other companies are likely to do."

That's especially so since Pfizer's decision follows a series of clinical failures by other companies pursuing Alzheimer's research – developments that can be extremely costly for the companies invested in the trials.

We'll have to wait and see what happens here – and hope the companies committing to this research keep focussed on what's really at stake here.

"[N]euroscience research is high risk, in that failure for pharmaceutical companies comes at a high price,"Alzheimer's Research's director of policy, Matthew Norton, told The Times.

"[But] the potential benefits of success to the millions of people around the world living with dementia are too great to ignore."