Despite the serious negative consequences of living with depression, the condition is notoriously hard to diagnose. Estimates suggest that as many as two thirds of people living with depression do not realize that they have a treatable condition and, as a result, do not seek treatment. Even those who do seek treatment—either voluntarily or at the request of friends, family members, or doctors—are often ashamed to admit to their symptoms. Any diagnosis relying on self-report—whether it be a self-administered test or a clinical interview in a doctor’s office—is prone to selective reporting. No one wants to be depressed and, as a result, many people suffering from depression may answer from the perspective of how they want to feel, rather than how they actually feel.
In this way, diagnosing people at risk for depression is similar to diagnosing people at risk for committing suicide. Those most vulnerable —the people who actually intend to carry out the act—are unlikely to reveal this information. As a result, clinical psychologists have developed ways to test for suicidal intentions that circumvent self-report issues; for example, by using implicit methods that may reveal intentions of which the patients themselves are unaware.
Perhaps the most exciting implication of the data linking internet usage to depression is the possibility that clues of depressive tendencies can also be identified early, not only before the opportunity for professional diagnosis but perhaps also before people are aware of it themselves. An intervention as simple as tracking internet use may allow depression, a prevalent and dangerous illness, to be discovered and treated earlier, more effectively, and for more people.