People do not have to be severely depressed or anxious to be at increased risk for physical or mental disability, researchers found, as even mild distress led to serious loss of function for some study participants.
Analysis of data on more than 17,000 individuals in Sweden indicated that mild psychological distress approximately doubled the likelihood of a subsequent diagnosis of somatic or psychiatric disability (hazard ratios 1.7 and 2.2, respectively, P<0.05, relative to no distress), reported Dheeraj Rai, MBBS, of the University of Bristol in England, and colleagues.
The development of cost-effective psychosocial or medical interventions for people with mild psychological distress may be a priority worth pursuing as it may reduce the disability burden, improve health outcomes and generate significant societal savings,” Rai and colleagues wrote online in the Journal of Epidemiology and Community Health.
- Note that this study indicates that a large fraction of disability pensions awarded for a psychiatric diagnosis can be attributed to psychologic distress.
- Point out that increasing levels of psychological distress at baseline in this study, beginning with mild distress, were significantly associated with eventual long-term disability.
Among all disability pensions awarded to cohort members for physical or psychiatric problems, 7% could be attributed to mild distress earlier in life, the researchers calculated.
The findings were part of a longitudinal population-based study conducted in Stockholm that began in 2002, comprising 17,205 adults 18 to 64 years old at baseline.
At study entry, participants completed the 12-item General Health Questionnaire (GHQ), which measures psychological distress on a 12-point scale. Rai and colleagues classified scores of 1 or 2 as mild.
Just over 10,000 participants had GHQ scores of zero at baseline. Mild distress was found in 2,878. A similar number reported moderate distress (GHQ score 3 to 7) and about 1,300 had severe distress (score 8 to 12).
A total of 649 disability pensions were awarded to study participants during subsequent follow-up, about 70% of which were for physical illnesses.
After adjusting for a large number of baseline factors also associated with disability risk — such as age, gender, foreign birth, education level, smoking, pain, and diagnosed illnesses — those with mild distress were at increased risk for receiving a disability pension compared with participants with GHQ scores of zero at baseline:
- Physical disability: HR 1.7 (95% CI 1.3 to 2.2)
- Psychiatric disability: HR 2.2 (95% CI 1.4 to 3.6)
The increased risk for physical disability with mild distress was not markedly different from that associated with moderate or severe baseline distress, which had hazard ratios of 1.8 (95% CI 1.4 to 2.4) and 2.5 (95% CI 1.9 to 3.4), respectively.
Disability for psychiatric reasons were more clearly associated with the level of baseline distress, with hazard ratios of 4.3 and 10.9 for moderate and severe distress, respectively.
Baseline psychological distress at all severity levels accounted for 27% of the physical disability pensions and 64% of psychiatric disability pensions, Rai and colleagues estimated.
The researchers noted that targeting those with mild distress for interventions will be a challenge. “People with psychological distress often present to primary care doctors but for many, especially those with mild and nonspecific presentations, this goes undetected,” they wrote.
Rai and colleagues also warned that patients “should not be overly medicalized.” Whether treatment for mild distress would reduce later rates of disability remains uncertain, they noted.
“Evidence relating to the possibility and means of reducing milder forms of psychological distress in the population is extremely limited, and we hope our study will fuel this line of empirical inquiry,” they wrote.
Limitations of the study included reliance on a primary diagnosis for receipt of disability pensions, which may also have been based on comorbid conditions such as personality disorders. Rai and colleagues also had no data on the reasons for baseline distress or its course over time.
The study was funded by the Stockholm County Council, Swedish Council for Working Life and Social Research.
Study authors declared they had no competing financial interests.
Rai D, et al “Psychological distress and risk of long-term disability: population-based longitudinal study” J Epidemiol Community Health 2011; DOI:10.1136/jech.2010.119644.