Ability to acquire an employment and hold it, cognitive and social skills required for the job, dealing with workplace culture, or studying as a student.In terms of total disability-adjusted life years (DALYs), which is an estimate of how many years of life are lost due to premature death or to being in a state of poor health and disability, mental disorders rank amongst the most disabling conditions. Unipolar (also known as Major) depressive disorder is the third leading cause of disability worldwide, of any condition mental or physical, accounting for 65.5 million years lost. The first systematic description of global disability arising in youth, in 2011, found that among 10- to 24-year-olds nearly half of all disability (current and as estimated to continue) was due to mental and neurological conditions, including substance use disorders and conditions involving self-harm. Second to this were accidental injuries (mainly traffic collisions) accounting for 12 percent of disability, followed by communicable diseases at 10 percent. The disorders associated with most disabilities in high-income countries were unipolar major depression (20%) and alcohol use disorder (11%). In the eastern Mediterranean region, it was unipolar major depression (12%) and schizophrenia (7%), and in Africa it was unipolar major depression (7%) and bipolar disorder (5%).Suicide, which is often attributed to some underlying mental disorder, is a leading cause of death among teenagers and adults under 35. There are an estimated 10 to 20 million non-fatal attempted suicides every year worldwide.
A 2002 editorial in the British Medical Journal warned of inappropriate medicalization leading to disease mongering, where the boundaries of the definition of illnesses are expanded to include personal problems as medical problems or risks of diseases are emphasized to broaden the market for medications.Gary Greenberg, a psychoanalyst, in his book "the Book of Woe", argues that mental illness is really about suffering and how the DSM creates diagnostic labels to categorize peoples suffering. Indeed, the psychiatrist Thomas Szasz, in his book "the Medicalization of Everyday Life", also argues that what is psychiatric illness, is not always biological in nature (i.e. social problems, poverty, etc. ), and may even be a part of the human condition. Potential routine use of MRI/fMRI in diagnosis
in 2018 the American Psychological Association commissioned a review to reach a consensus on whether modern clinical MRI/fMRI will be able to be used in the diagnosis of mental health disorders. the criteria presented by the APA stated that the Biomarkers used in diagnosis should: 

"have a sensitivity of at least 80% for detecting a particular psychiatric disorder"
should "have a specificity of at least 80% for distinguishing this disorder from other psychiatric or medical disorders"
"should be reliable, reproducible, and ideally be noninvasive, simple to perform, and inexpensive"
proposed biomarkers should be verified by 2 independent studies each by a different investigator and different population samples and published in a peer-reviewed journal.the review concluded that although neuroimaging diagnosis may technically be feasible, very large studies are needed to evaluate specific biomarkers which were not available.