Intra-individual fluctuation patterns of depressive symptoms assessed over 12 years

Background:

Depressive symptoms (DS) are a common mental disorder, however less is known about intra-individual fluctuations over a long time period. Aim here is to categorize fluctuation patterns and to describe study participants with different patterns of changes of DS over a period of 12 years in regard to socioeconomic and lifestyle factors.

Methods:

Data of 4,251 participants (45 – 75 years; 51.0% women) of the Heinz Nixdorf Recall Study with at least 2 of the maximum 9 possible measurements were included. DS are defined by a cutoff ≥17 assessed by the CES-D (short form). Based on the individual mean values and standard deviation from all measurements, 4 groups (G) 1 “stable low”, 2 “stable high”, 3 “stable around cutoff”, 4 “large fluctuations” were built. The groups are described according to age, sex, education and physical inactivity.

Results:

Most participants (83%) showed stable low DS, whereas 9% had great DS fluctuations (G4), 2% performed stable high values (G2) and 6% stable DS around the cutoff (G3). Interestingly G4 is characterized by a higher proportion of women (61%; 49% G1, 69% G2, 64% G3), younger age (mean age: 58.4y, G1 59.2, G2 58.8, G3 60.7) and highest share (12%) of highly educated (4% G2, 8% G3, 9% G4). G2 is more often physically inactive (57%) compared to those with stable low DS with 43% (G3, G4 53%).

Conclusion:

The longitudinal approach reveals more than 15% of the participants performing highly different results when assessing depressive symptoms. Fluctuation patterns differ by age, sex and lifestyle factors. In further analyses, we will analyze influencing factors of fluctuation patterns in more detail. Overall, it is recommended to analyze depressive symptoms over a longer time period and to take fluctuations patterns of depressive symptoms into account.