With therapists in high demand and long waiting lists that make it difficult to find a provider, using a mental health app might seem like a relatively inexpensive way to get help.

These apps claim to help with issues like addiction, anxiety, and schizophrenia by using tools like games, therapy, or mood-tracking diaries. Most are not regulated. Some apps are considered useful and safe, but others may have shaky privacy policies and a lack of high-quality research demonstrating that the apps live up to their marketing claims.

The lack of regulation has created a "Wild West" that was worsened when the Food and Drug Administration loosened its requirements, according to the executive director of One Mind PsyberGuide.

It is difficult to say how many mental health apps are out there, but one estimate from last year said there were at least 10,000 available for download. Digital products are becoming profitable. At the end of last year, it was predicted that global spending on mobile mental health applications would reach $500 million.

How do you make a decision about adding one to your phone? Several experts were asked for help.

The director of the digital psychiatry division at Beth Israel Deaconess Medical Center said that mental health apps can help people gain insights into how their thoughts, feelings and actions interact with each other. He said that they can help facilitate the skills that patients learn during therapy.

Mental health apps can work nicely with physical activity goals, such as step counters, because they can help reduce anxiety and depression.

She said that apps that teach skills such as deep breathing can be helpful to anyone who is experiencing stress.

Some people don't like apps.

People with moderate or severe depression may not have enough motivation to complete modules on a mobile app.

If you have impairing symptoms, no.

They are not stand-alone treatments and can be used with therapy.

The senior director of health care innovation at the American Psychological Association said that mental health apps should teach skills or educate.

She said that it could be this opening to thinking about more professional help.

Dr. Torous gives his patients a free app called MindLAMP, which he created to enhance their mental health treatments. It can be used to track people's sleep patterns, physical activities and changes in symptoms, as well as to tailor the homework that therapists give their patients.

The Food and Drug Administration regulates a small subset of apps that provide treatment or diagnosis, or are associated with regulated medical devices. Most mental wellbeing apps are not subject to government scrutiny.

Some apps make marketing claims that are questionable, experts warn, or even worse, offer inaccurate and potentially harmful information.

The number of products far outstrips the research evidence that is out there, said Dr. Schueller, who is also a clinical psychologist and associate professor at the University of California, Irvine.

The privacy of a patient's health records is protected by the Health Insurance Portability and Accountability Act.

In a recent paper, Dr. Torous and his colleagues looked at regulatory gaps in digital health apps and found some problems that could arise, such as inaccurate phone numbers for suicide crisis help lines. Only 12 of the 36 top-ranked apps for depression and smoking cessation accurately disclosed that they shared user data with Facebook or Google, according to an earlier study.

In March, a study concluded that an app created to help those with schizophrenia did not perform better than a placebo.

Dr. Torous said that all the apps that claim to be effective in early or preliminary studies need to study themselves with higher quality science.

Even though an app is popular in the online marketplace, it doesn't mean it will be safer or more effective.

It was difficult to understand what apps to use for patients as a clinician who has used apps for years.

Try to make an informed decision about which app would be the best match for you, instead of looking for the best app or the one with the most ratings.

The website Mind Apps was created by clinicians at Beth Israel Lahey Health in Massachusetts. It is updated every six months. Cost, security and privacy concerns are some of the factors that reviewers look at.

One Mind PsyberGuide evaluates health apps for credibility, user experience and transparency of privacy practices. The project, which is affiliated with the University of California, Irvine, has more than 200 apps in its database.

Although MindApps and One Mind Psyberguide present an overview of an app's privacy policy, you may want to dig into the specifics yourself.

Dr. Collier said to look at what kind of information it collects, its security measures, and whether it sells information to third parties or uses it for advertisements.

Less than half of mobile apps for depression have a privacy policy, and most privacy policies are only provided after users enter their data, according to a study.

The lead author of the study said that some people have reservations about using mobile apps when they don't know how their data is being used.

She said to choose your app based on the information available and your own comfort level.

The answer may depend on who you ask. All of the experts spoke highly of the mental health apps developed by the federal government, like PTSD Coach, which is for people who are practicing cognitive processing therapy with a professional mental health care provider.

These apps are free and well studied. They have good privacy policies that state that personal information won't be shared with a third party.

Dr. Collier also recommends:

  • The coach of the DBT.

  • The diary is about the thoughts of the CBT.

  • An app designed by the U.S. Department of Defense to teach belly breathing is called Breathe2Relax.

  • The Defense Health Agency created the Virtual Hope Box to offer support for emotional regulation and stress reduction.

    The University of California, San Francisco's Psychiatry and Behavioral Sciences department website has a list of apps. There are several free options on the list.