Why Are Mental Health Conditions Lasting Longer?

New research from the Netherlands suggests that anxiety, mood and substance use conditions are lasting longer than they did 12 years ago, highlighting growing challenges around treatment and long-term recovery.

Are mental health conditions lasting longer?

Common mental health conditions may be becoming harder to recover from, according to new research published in Psychological Medicine. Researchers found that people experiencing a mental disorder are now more likely to continue experiencing mental health difficulties three years later than people with a mental disorder assessed around 12 years earlier.

The study follows previous research showing that common mental health conditions have become more prevalent in the Netherlands. Researchers wanted to understand whether this increase could partly be explained by existing conditions lasting longer, rather than only by more people developing mental health problems for the first time.

What did the study find?

Researchers analysed data from two large, representative surveys of the Dutch population. The first group was assessed between 2007 and 2009 and followed up around three years later, while the second was assessed between 2019 and 2022 and followed up over a similar period. This allowed the researchers to compare the persistence of mental health conditions across the two periods.

Among people who had a mental disorder at the start of the study, 42.7% of the earlier group still had a mental disorder three years later. In the more recent group, this increased to 57.9%. Artemis Gkitakou, a PhD candidate at Amsterdam UMC and the Trimbos Institute, described the difference as substantial, noting that almost six in 10 people in the more recent group experienced a mental disorder during the follow-up period.

Anxiety, mood and substance use conditions all showed increases

The increase was seen across all three categories of conditions studied. Persistence of anxiety disorders increased from 24.4% to 40.1%, while persistence of mood conditions increased from 33.5% to 48.8%. For substance use conditions, persistence increased from 33.7% to 45.5%.

The researchers also looked at persistence more broadly, including people whose mental health condition had changed. Among people in the more recent group who initially had an anxiety disorder, 41.6% still had anxiety three years later. However, 57.1% had experienced some form of mental disorder, even if it was a different condition.

Gkitakou said this broader view is important because people may move between different mental health conditions over time, meaning recovery should not necessarily be understood only in terms of the original diagnosis.

Who may be more vulnerable?

Younger adults and people living in cities were more likely to experience persistent mental health conditions. Childhood trauma and near-daily drug use were also associated with longer-lasting difficulties.

However, these factors were broadly similar across both time periods, suggesting they do not explain why persistence has increased overall. The researchers also found that changes in individual risk factors and mental health service use did not fully account for the increase.

What could explain the change?

The study cannot establish why mental health conditions appear to be becoming more persistent. The researchers suggest that future studies should examine wider societal, environmental and healthcare-related factors, including potential economic and environmental pressures.

There are also limitations to consider. The study relied on structured diagnostic interviews based on participants' reported symptoms, and the more recent survey had a lower response rate, although the researchers adjusted the data to reflect the wider population.

Importantly, "persistence" did not mean that someone experienced a condition continuously throughout the entire three years. It meant they experienced a disorder at some point during the follow-up period, and people could move from one type of mental health condition to another.

The researchers say the next step is to understand why persistence has increased and whether greater continuity of care and more attention to changes between diagnoses could support longer-term recovery.