by Eugene Rubin MD, PhD and Charles Zorumski MD

How many individuals receive treatment for psychiatric symptoms during their lifetimes? An important recent study by Lars Kessing, Simon Ziersen, Avshalom Caspi, Terrie Moffitt, and Per Andersen adds to current knowledge regarding this question.

Their research utilized comprehensive registries of all people living in Denmark. These registers contain data regarding demographics, socioeconomic status, health information including psychiatric diagnoses, and medication records. The investigators limited their study to a randomly selected sample of 1.5 million from the over 5 million people born between 1896 and 1995. They analyzed data on these individuals from 1996 to 2018. Persons who received treatment for psychiatric disorders prior to 1996 were excluded from their analyses as were people who died or emigrated from Denmark before 1996. Thus, records of over 1.3 million individuals ranging in age from 0 to 99 were reviewed over 23 years for evidence of onset of treatment for psychiatric symptoms. This research design allowed the investigators to determine the percentage of individuals who initiated psychiatric treatment at specific times during their lifespan.

How did the researchers identify those who received psychiatric treatment? They were able to tell when a person received a diagnosis for any psychiatric disorder in inpatient and outpatient hospital settings from the Danish Psychiatric Central Research Register. In addition, they were able to collect data regarding treatment with psychiatric medications from Medicinal Product Statistics. The investigators used a variety of techniques to maximize the chances that psychotropic medications were prescribed for psychiatric symptoms and not for treatment of non-psychiatric conditions.

The results of their analyses are eye-opening: About 15% of the sample were treated for psychiatric symptoms by age 20; 40% by age 40; 60% by age 60; and 80% by age 80. The percentages were slightly higher for females than males.

Antidepressants and anti-anxiety medications were the two most common groups of psychiatric medications used by this population. By age 80, over 60% had used antidepressants, about 55% had used antianxiety agents, and about 25% had used antipsychotics. Far fewer individuals were ever prescribed ADHD medications or lithium.

The research team found that the presence of psychiatric symptoms was associated with “socioeconomic difficulties, including lower income, unemployment, and increased likelihood to live alone and to be unmarried.”

The results of this study indicate that a large majority of individuals will likely be treated for psychiatric symptoms during their lifetimes. Denmark has a system of comprehensive data registers, and health care is free. This type of comprehensive survey would be difficult to perform in the United States; however, data from various U.S. surveys also suggest a high lifetime incidence of psychiatric disorders.

It is interesting to consider why those with mental illness continue to experience stigma from society. Do the results of this study suggest that those who stigmatize individuals with psychiatric illnesses might themselves face such symptoms either currently or later in life? Perhaps understanding that such symptoms are likely a part of most of our lives and those of our family and friends will encourage new attitudes toward mental health.