Understanding personalized dynamics to inform precision medicine: a dynamic time warp analysis of 255 depressed inpatients.
BACKGROUND
Major depressive disorder (MDD) shows large heterogeneity of symptoms between patients, but within patients, particular symptom clusters may show similar trajectories. While symptom clusters and networks have mostly been studied using cross-sectional designs, temporal dynamics of symptoms within patients may yield information that facilitates personalized medicine. Here, we aim to cluster depressive symptom dynamics through dynamic time warping (DTW) analysis.


METHODS
The 17-item Hamilton Rating Scale for Depression (HRSD-17) was administered every 2 weeks for a median of 11 weeks in 255 depressed inpatients. The DTW analysis modeled the temporal dynamics of each pair of individual HRSD-17 items within each patient (i.e., 69,360 calculated "DTW distances"). Subsequently, hierarchical clustering and network models were estimated based on similarities in symptom dynamics both within each patient and at the group level.


RESULTS
The sample had a mean age of 51 (SD 15.4), and 64.7% were female. Clusters and networks based on symptom dynamics markedly differed across patients. At the group level, five dynamic symptom clusters emerged, which differed from a previously published cross-sectional network. Patients who showed treatment response or remission had the shortest average DTW distance, indicating denser networks with more synchronous symptom trajectories.


CONCLUSIONS
Symptom dynamics over time can be clustered and visualized using DTW. DTW represents a promising new approach for studying symptom dynamics with the potential to facilitate personalized psychiatric care.
['Hebbrecht|K|K|', 'Stuivenga|M|M|', 'Birkenhäger|T|T|', 'Morrens|M|M|', 'Fried|E I|EI|', 'Sabbe|B|B|', 'Giltay|E J|EJ|']
D000328:Adult D000368:Aged D016000:Cluster Analysis D003430:Cross-Sectional Studies D003661:Decision Support Techniques D003865:Depressive Disorder, Major D005260:Female D006801:Humans D007206:Individuality D008297:Male D008875:Middle Aged D057285:Precision Medicine D011613:Psychotherapy D013997:Time Factors D016896:Treatment Outcome
Major depressive disorder Symptom dynamics Symptom trajectories Cluster analysis Inter-individual variation Intra-individual variation Routine outcome monitoring