As smartphone users have grown more comfortable forking over information about their bank accounts and physical whereabouts to mobile applications, a growing group of app developers are betting health-related data will be next.

Consider Bethesda-based M3 Information. The company has created an app that asks patients a series of nearly 30 questions designed to assess whether they exhibit symptoms of depression, anxiety, bipolar disorder or post-traumatic stress disorder.

But the app, known as WhatsMyM3, stops short of a definitive diagnosis. Instead, it issues a score that suggests the patient may be at an elevated risk and recommends they discuss the results with a primary care physician.

In some ways, the app is indicative of the broader mobile health market. Applications are being built to assist physicians at a patient’s bedside or help remotely monitor chronic conditions, but remain somewhat limited by concerns about their ability to ensure patient safety and privacy.

That’s caught the eye of federal regulators. The Food and Drug Administration will likely finalize its first-ever guidance on mobile health applications later this year, giving the agency at least some oversight of mobile products that replace or complement other medical devices, such as a stethoscope or EKG machine.

A screenshot of the app WhatsMyM3.

Bakul Patel, a policy adviser who helped craft the guidelines, said the pace of innovation for mobile tends to be faster than that of the medical devices and software the agency has had to monitor to date.

Indeed, the agency is already compiling a set of guidelines for mobile apps that assist doctors in forming a diagnosis or treatment plans, Patel said. WhatsMyM3 could eventually fall into that category.

Mohamad Makhzoumi, a partner at investment firm New Enterprise Associates, said health care start-ups are wary of pending regulatory changes, but added that federal oversight has long created an inherent degree of uncertainty in the health care industry.

“It hasn’t slowed down the pace of company formation or capital raise, but it’s something that is difficult to nearly impossible to handicap,” he said. “So what you’re seeing today is people willing to take the risk given that the opportunity is so large.”

But those companies, including M3 Information, are also contending with critics who worry whether a patient’s privacy can be safeguarded as more of their sensitive information is accessed via the Internet.

M3 Information, for example, also has a Web site interface and software for doctors that allows them to track a patient’s M3 score over time and assess whether their mental health condition has improved.

The current iteration of the WhatsMyM3 mobile app holds a patient’s results on his or her phone. It doesn’t connect directly to M3 Information’s own Web site or sync with Microsoft HealthVault, a Web portal where patients can store medical information, though that may come in the future.

“There’s even a heightened level of sensitivity around [mental health] and our principle is to provide as much choice to the consumer as possible so they feel they are in control of their data and what it’s being used for,” said Dr. Steve Daviss, the company’s chief medical information officer.

But Patricia Mechael, executive director of the District-based mHealth Alliance, said some of those concerns are being alleviated as more firms enter the health care technology market and create security solutions. The finance industry, she said, has overcome similar obstacles.

“There is enough experience with different platforms and systems that have already done it and standards are being developed for actually continuing to do it,” Mechael said. “It’s not as big of a hurdle as it was, say, a year ago.”