This simple phone game could help detect depression in three minutes

A simple smartphone game that asks people to collect falling apples from digital trees could help doctors identify depression in just a few minutes

A new study by NYU Langone Health, focused on a common symptom of depression called anhedonia -- the reduced ability to feel pleasure or enjoy things that once felt rewarding. Researchers say this symptom is seen in around 70% of people with major depressive disorder.

The study is published in the journal Proceedings of the National Academy of Sciences.

The experimental tool works like a game and can be played remotely on a smartphone. Researchers say it was able to identify people with depression in as little as three minutes.

“Our behavioural game gives us clues to what is happening in the brains of patients with depression,” said Paul W. Glimcher, one of the senior authors of the study.

HOW THE GAME WORKS

The researchers tested the game on 120 people. Among them, 50 had already been diagnosed with major depression, while 70 did not have depression.

Players were asked to collect apples falling from digital trees. But there was a catch, the number of apples from each tree slowly reduced over time.

Researchers watched how long each person stayed with one tree before deciding to move to another.

Healthy participants usually stayed with a tree until the number of apples dropped to around five. But people with depression tended to give up much earlier, usually when the tree was still giving eight or nine apples.

This suggested that people with depression stopped finding the activity rewarding much sooner.

The researchers believe this happens because depression changes how people judge pleasure and rewards.

Activities that may still feel enjoyable to others can start feeling less worthwhile to someone with depression.

WHAT THE STUDY FOUND

The team says depression may affect a person's “expectation level”, the point at which something feels rewarding enough to continue.

In another part of the study, participants were asked how much they would pay for different snacks. First, they saw snacks they really liked. Then, they were shown a random mix of snacks that were less appealing.

Healthy participants briefly became harder to impress after seeing their favourite snacks, so they valued the random snacks less. But after some time, their thinking returned to normal.

People with depression reacted differently. Even after moving on from their favourite snacks, their expectations did not return to normal as easily. Researchers say this may show that people with depression struggle to adjust their sense of reward when situations change.

COULD THIS CHANGE DEPRESSION TREATMENT?

The researchers believe the game could eventually become a quick and low-cost way to help doctors monitor depression remotely.

It could also help doctors identify specific types of depression and personalise treatment better.