For many, smart phones have replaced calculators, alarm clocks, MP3 players, cameras, calendars and road atlases, becoming the ultimate handheld gadgets. Now, a new application designed to detect depression in its users may even replace therapy as well.

Researchers at Northwestern University are developing a smart phone app called “Mobilyze!” that uses context settings to detect depression. Data sensors embedded in the phone will send alert messages that suggest “opening a window” or “calling a friend” when a user’s location, social setting, mood or activities indicate depression.

So if iPhone users are sitting at home and feeling depressed for days on end, their smart phones can sense it.

“The goal is that the phone can learn to identify states in which the user is at risk for worsening, thereby being able to assist the person [on] a road to recovery,” said psychologist David Mohr, a primary researcher on the app.

So far, studies have shown positive results. An early version was tested on eight patients with severe depression. One participant dropped out because of technical difficulties, but the remaining seven showed significant improvement after using their “phone therapist,” Mohr said.

He believes that while the app could never replace traditional treatment, it has the ability to significantly alleviate depressive symptoms between therapy sessions.

“Mobile phones have the potential to engage with people in the environment where they live and provide assistance in the moment when they need and want it,” Mohr said.

The Centers for Disease Control and Prevention reported in 2011 that an estimated 10 percent of adult Americans, approximately 30 million people, suffer from clinical depression. They reported that individuals who are unemployed or unable to work and people without health insurance are at particularly high risk for developing major depression.

“Low–intensity, low–cost treatments [like Mobilyze!] can play an important role in improving public health,” Mohr said.

Julie Hersh, author of “Struck by Living,” once suffered from depression and believes the app could be an effective way to alleviate symptoms because the alert messages would make patients more aware of their feelings and what triggers them.

“Everyone has different things, such as exercise and good friendships, that help them maintain their mental health,” Hersh said. “If the app reminds people of the unique things that make them happy, it could really help.”

Although considered groundbreaking to some, the idea of having a mobile therapy icon appear alongside Facebook and Words with Friends is disturbing to some critics.

Many mental health experts are concerned that advice from a cell phone is not an adequate way to treat depression because human interaction has been proven to be a critical part of combating the condition.

“I don’t believe for one moment that a virtual technology is going to replace the important process that occurs when therapists and patients work together in person,” said psychologist Rosalind Dorlen.

However, Dorlen said the app could be a good supplement to traditional therapy. She said that people with autism and other behavioral disorders might greatly benefit from Mobilyze! because it would make them more comfortable with discussing their emotions.

Mohr believes that traditional therapy is a critical tool for alleviating depression, and he does not intend for the app to replace it, he said.

“Mobilyze! has been criticized with the argument that people need the warmth of a human relationship,” he said. “I agree that human interaction is critical to psychotherapy, but this is a different tool.”

Mohr and his colleagues plan to do more large-scale testing of the app this summer. They plan to release it to the public when they are certain of its effectiveness. He estimated that Mobilyze! will be available for purchase within a couple of years.