The idea of Google offering a quick online screening test for users who search for "am I depressed" has split opinion among medical experts.
Some say that although the test wouldn't be an official diagnosis, it could nudge people to visit doctors and access useful resources. But others say the test could over-diagnose people - and users should be concerned about their data privacy.
A Google search for "Am I depressed?" (or similar) via mobile phone will offer a link to the patient health questionnaire (PHQ-9) test - a screening tool used by doctors to monitor the severity of depression and response to treatment. Links to materials and telephone helplines will be offered with test results for people with higher scores.
Clinical psychiatrist Ken Duckworth points out that this is not meant to replace clinical screening, nor does it constitute a universal screening program. Instead, "it is intended to prompt informed conversations with clinical professionals and to suggest potentially helpful resources."
And he stresses that the result alone cannot drive treatment without a professional making a formal diagnosis. Nor should it threaten privacy, as Google will not store or log any responses or results, or link these with individuals' other data.
"Increasing the motivated public's understanding of this validated screening tool could help to empower patients," he writes. "Informed people may have a better chance of getting the help they may need."
But Clinician and Professor of psychological medicine, Simon Gilbody, believes that unregulated screening for depression will be ineffective and worries if could cause harm.
He raises concerns over inadequate treatment resources to meet demand and assurances about privacy and misuse of data.
"There are reasons to be concerned that data generated by a depression screening programme might be used to market antidepressants," he says.
He argues that depression should be diagnosed following a clinical assessment rather than a one-time screening test, warning that "episodes of transient (and self limiting) psychological distress will be confused with pervasive disorders that warrant treatment."
And he points out that recent disease awareness campaigns and unregulated screening programmes "present risks of overdiagnosis, supplier induced demand, and inappropriate treatment."
"Google's initiative has been reported positively and uncritically despite bypassing the usual checks and balances that exist for good reason. It is unlikely that their initiative will improve population health and may in fact do harm," he concludes.
Mental health services user David Gilbert argues that by offering the PHQ-9 test online, Google is entrenching outdated ways of thinking about mental health.
"This diagnostic tool focuses on physiological and biomedical symptoms", Gilbert says. "It puts firm emphasis on dysfunction and frames distress from the outset as an illness."
Gilbert points to other ways to make a more meaningful diagnosis, but asks how much room might there be for this sort of dialogue if Google's approach spreads?
There is hope, he says, but change will happen only if service users have power and are equal partners with corporations like Google, so that decisions are made together.
"Only then will online tools be a key that unlocks sense making, choice, and control."