In treating mood disorders, target motor activity instead
Motor activity appears to play a central role in mood regulation, according to a recent study, which also reports that subjective energy is important in motor activity.
“Using mobile monitoring and traditional clinical methods, we examined the highly dynamic interplay of multiple brain-body systems involved in the homeostatic regulation of human energy, mood, motor activity and sleep,” said researchers, adding that instead of conventionally targeting mood, interventions may see more success if focused on motor activity.
Using an actigraphy device, researchers monitored the motor activity and sleep duration of 242 adults (mean age 48±16.9 years; 61.9 percent female), of whom 22.3 percent (n=54) had bipolar disorder. Most (40.1 percent) had no lifetime history of mood disorders, while 37.6 percent had major depressive disorder. [JAMA Psychiatry 2018;doi:10.1001/jamapsychiatry.2018.3546]
There was a significant, cross-domain and bidirectional association between motor activity (β, –0.027; p=0.04) and sleep duration (β, –0.154; p=0.04). That is, a longer sleep duration the previous night was associated with reduced activity the following day, while a lower level of activity during the day tended to prolong sleep duration that following evening.
Researchers also observed a similarly significant and bidirectional association between motor activity (β, 0.176; p=0.03) and energy level (β, 0.027; p=0.03).
On the other hand, only a unidirectional relationship was seen between motor activity and changes in mood (β, –0.018; p=0.04). Moreover, mood showed no significant direction of association with energy level or sleep duration on the following evening.
“The unidirectional associations of motor activity with depressed mood suggest that novel pharmacologic, physical and behavioural therapeutic approaches focused on increasing energy and activity may be more effective than current treatments that target mood elevation or stabilization,” said researchers.
Monoamine oxidase inhibitors, for example, act through stimulating energy and activity instead of trying to uplift mood, they continued. These types of medications have been shown to be successful in treating low energy levels in the atypical subtype of depression. [J Clin Psychiatry 2007;68:e10]
The present study employed a nested case-control design with community-based participants. Aside from wearable actigraphy devices, participants were also made to accomplish ecological momentary assessments four times per day for the evaluation of mood and energy levels. Semi-structured interviews were conducted for the diagnosis of mood disorders.
“The application of real-world mobile technology to track human behaviour and physiologic function in real time, coupled with advances in circadian medicine and molecular biologic systems research, provides unprecedented opportunities for increasing our understanding of the regulation of the core features of mood and other disorders,” said researchers.
This then will allow us “to gain insights into their underlying biologic, genetic and environmental mechanisms and to define novel targets for intervention,” they added.