Mechanisms Underlying Antidepressant Effects of Physical Activity

Summary

It is well established that any level of physical activity can help prevent and treat depression, with more strenuous activity having a greater effect. Understanding the mechanisms driving this antidepressant effect is important because it could allow exercise programmes to be made more effective, accessible, and targeted. Such knowledge could contribute to social prescribing, increasingly a priority for mental healthcare. Importantly, physical activity is highly scalable, low cost, well suited to early intervention, and has beneficial impacts on physical health co-morbidities. This trial may provide initial indications of whether there are sub-groups of depressed individuals who are particularly likely to benefit from physical activity, lead to strategies to personalise physical activity prescription based on motivational factors, and pave the way for augmentative approaches, for example combining physical activity with psychological interventions.

To date the mechanisms driving the antidepressant effects of physical activity in humans are poorly understood. Building on links between depressive symptoms, reward processing and dopamine, plus evidence from animal studies that physical activity is anti-inflammatory and boosts both dopamine and reward processing, the overarching aim of this trial is to understand the mechanisms underlying the effects of physical activity in depression, focusing on the concept of motivation.

The key objective is to conduct a randomised controlled trial (RCT) in N=250 depressed participants comparing aerobic exercise to a stretching/relaxation control condition, examining a range of mechanistic factors. The proposed trial will examine the impact of physical activity at multiple, linked potential levels of explanation: (1) immune-metabolic markers; (2) dopamine synthesis capacity; (3) activation in the brain's reward and effort processing circuitry;(4) effort-based decision making incorporating computational analysis; and (5) symptom networks based on fine-grained, daily measurements.

Conditions

• Depression

Interventions

OTHER

Aerobic exercise

This will be delivered by coaches in a small group class format. Participants will complete the trial in staggered cohorts, with no more than six participants per class. Intervention activities will be tailored to each individual's own ability and fitness level.

OTHER

Stretching and relaxation

This will be delivered by coaches in a small group class format. Participants will complete the trial in staggered cohorts, with no more than six participants per class. Intervention activities will be tailored to each individual's own ability and fitness level.

Sponsors & Collaborators

• King's College London

  collaborator OTHER

• Queen Mary University of London

  collaborator OTHER

• University of Dublin, Trinity College

  collaborator OTHER

• University College, London

  lead OTHER

Principal Investigators

• Jonathan P Roiser, PhD · University College, London

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-04-01

Primary Completion

2027-08-31

Completion

2028-01-31

Countries

• United Kingdom

Study Locations