Swarm intelligence is a concept inspired by the behaviour of social insects like ants, bees, and termites, where a group of relatively simple individuals can collectively exhibit complex and intelligent behaviour. Swarm intelligence is characterised by decentralised, self-organised natural or artificial systems, where individual agents follow simple rules and interact with one another and their environment. Through these interactions, the group as a whole exhibits sophisticated behaviours that can adapt to changing circumstances and solve complex problems. The concept of swarm intelligence was introduced in 1989 and has already found applications in various fields, from robotics to optimisation algorithms. In recent years, swarm intelligence has begun to show promise in the field of psychiatry, offering an unprecedented approach to understanding and treating mental health disorders. In psychiatry, this concept is being applied to understand the collective dynamics of mental health and develop innovative therapeutic approaches. Understanding these dynamics can provide insights into the spread of mental health information, stigma reduction, and peer support networks. This chapter explores the emerging role of swarm intelligence in psychiatry, its potential benefits, and current applications.