BACKGROUND
Cognitive symptoms are common in major depressive disorder, and may help to identify patients that need treatment or who are not experiencing adequate treatment response. Digital tools to provide real time data assessing cognitive function could help to support patients treatment and remediation of cognitive and mood symptoms.
OBJECTIVE
This study examined adherence, feasibility, and validity of a wearable high-frequency cognitive and mood assessment app over 6 weeks, corresponding to when antidepressant pharmacotherapy begins to show efficacy.
METHODS
Thirty patients (aged 19−63; 19 women) with mild-moderate depression participated. The new Cognition Kit application was delivered via the Apple Watch, providing a high-resolution touch screen display for task presentation and logging responses. Cognition was assessed by the n-back task up to 3 times daily and depressed mood by 3 short questions once daily. Selected tests sensitive to depression from the Cambridge Neuropsychological Test Automated Battery and validated questionnaires of depression symptom severity were administered on 4 occasions (baseline, weeks 1, 3, and 6). Adherence was defined as participants completing at least one assessment daily.
RESULTS
Adherence was excellent for mood and cognitive assessments (95% and 96%, respectively), did not deteriorate over time, and was not influenced by depression symptom severity or cognitive function at study onset. Daily mood assessments showed good correspondence with validated depression questionnaires (correlations range from .45 to .69 for total daily mood score) and daily cognitive assessments showed good correspondence with cognitive tests sensitive to depression (correlations ranged from .37 to .50 for mean n-back).
CONCLUSIONS
The study supports the feasibility and validity of high-frequency assessment of cognitive function and mood function using wearable devices over an extended period in patients with major depressive disorder.
CLINICALTRIAL
clinicaltrials.gov NCT03067506
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