A dopamine-driven second body clock could be the cause of mood swings in people with bipolar disorders.
A McGill University-led study, out of Canada, found a brain rhythm which worked in tandem with the body’s natural sleep-wake cycle.
Associate Professor Kai-Florian Storch said their findings suggested that regularly occurring mood switches in bipolar disorder patients were controlled by two “clocks”.
Associate Professor Storch said there was the biological 24-hour clock, and a second clock that was driven by dopamine-producing neurons that typically influence alertness.
He said a manic or depressed state may arise depending on how these two clocks, which run at different speeds, align at a given time.
“It may explain why bipolar patients alternate between mania and depression.
“Our model offers the first universal mechanism for mood switching or cycling, which operates analogously to the sun and the moon driving spring tides at specific, recurring times.”
Associate Professor Storch said the second dopamine-based clock probably stayed dormant in healthy people.
He said current treatments for bipolar disorder focused on stabilizing moods, but often didn’t address the root causes of mood swings.
“Our discovery of a dopamine-based arousal rhythm generator provides a novel and distinct target for treatment, which should aim at correcting or silencing this clock to reduce the frequency and intensity of mood episodes.”
Read the full study: Mesolimbic dopamine neurons drive infradian rhythms in sleep-wake and heightened activity state.
