For two decades, researchers have used brain-imaging technology to try to identify how the structure and function of a person’s brain connects to a range of mental-health ailments, from anxiety and depression to suicidal tendencies.

But a new paper, published Wednesday in Nature, calls into question whether much of these brain-imaging studies is actually yielding valid findings. Many such studies, the paper’s authors found, tend to include fewer than two dozen participants, far shy of the number needed to generate reliable results.

Read the full article at www.nytimes.com