An examination of serotonin and psychological variables in the relationship between exercise and mental health

Abstract

Research has revealed that exercise is effective for reducing symptoms of depression and anxiety. The mechanisms by which these reductions occur, however, have not been widely studied. To examine several potential theories, a prospective, randomized, 7-week exercise intervention was conducted. Untrained participants were randomly assigned to an aerobic exercise group or to a stretching-control group. Participants completed several questionnaires to assess psychological variables, including measures of depression and anxiety, and blood was drawn at pre- and post-test to measure serum serotonin levels. A mixed-design ANOVA revealed that the exercise group had lower levels of depression than the stretching-control group after the intervention. The exercise group also showed a larger percentage decrease in serotonin than the stretching-control group. This reduction in blood serotonin after exercise is similar to the effects of selective serotonin reuptake inhibitors. Additionally, percent change in serotonin was found to partially mediate the relationship between exercise and depression.

A pilot study on the effects of exercise on depression symptoms using levels of neurotransmitters and EEG as markers

“…Emotional state and physical activity have been shown to result in changes in sympathetic nervous system activation correlating with decreases in plasma catecholamines; additionally, regular exercise has also been correlated with inhibition of platelet aggregability that may be further correlated with alterations in 5HT levels in the blood. [34,35] Although this study was not able to replicate the degree of findings from previous studies examining catecholamine and 5HT levels, [20,21,[25][26][27][28] this study did show a reduction in serum levels of catecholamine and 5HT levels within the exercise group; however, these decreases were not significant. On preliminary review of the data in this study, given the improvements in group mean BDI scores and serum 5HT and NE levels in the exercise group compared to the control group, the present research suggests that adherence to an individualized exercise regimen is indeed correlated with improvement in symptoms of depression and further correlated with decreased levels of serum NE and 5HT when compared to a control group.…”

“…[15][16][17] Built upon the vast array of literature highlighting the association between depression and lowered neurotransmitter levels, research studies are now using neurotransmitter measurements as a marker for depression. [18][19][20][21][22] Although there are no established norms for neurotransmitter levels, the correlation between depression and neurotransmitter levels has been well studied. In correlation with non-depressed individuals, depressed individuals have been found to have raised plasma catecholamine levels, including norepinephrine, epinephrine, and dopamine, high free-serotonin levels and low platelet-serotonin levels; [23][24][25][26] however, the findings regarding neurotransmitter changes during exercise have been inconsistent.…”

A review of lifestyle factors that contribute to important pathways associated with major depression: Diet, sleep and exercise

“…Human trials also provide evidence of exercise and its serotonin-enhancing effects. For example, untrained participants randomly assigned to an aerobic exercise group experienced greater changes in serum serotonin levels compared to those in a stretching-control group (Wipfli et al, 2011). Tryptophan availability, the precursor to serotonin, is also increased after acute exercise (Melancon et al, 2012).…”

Self-assessment of health-related quality of life in adults involved in regular physical activity

“…Tendencja ta potwierdza wyniki badań innych autorów [16,23]. W toku licznych badań wykazano silne związki mię-dzy aktywnością fizyczną a zdrowiem psychicznym człowieka, które przejawiają się redukcją przeciążeń psychicznych, stanów lękowych, wzrostem odporności na stres, poprawą nastroju i samopoczucia [24,25,26]. Co więcej, członkostwo w stowarzyszeniach rekreacyjnej aktywności fizycznej umożliwia nawiąza-nie interesujących znajomości, kształtuje kompetencje społeczne, takie jak umiejętność współpracy grupowej, co może mieć wpływ na wzrost satysfakcji czło-wieka z własnego życia.…”