Computational models and tools provide powerful assets for psychiatry research. We use these tools to uncover the cognitive and neural basis of human threat avoidance. Avoidance actions in the absence of real threat are a hallmark of several psychiatric conditions, such as anxiety disorder or post-traumatic stress disorder. We combine computational modelling with behavioural assays, neuroimaging and pharmacological intervention. In order to facilitate translation into clinical practice, we are testing a range of candidate treatments in laboratory models of psychiatric disorders, for example with synaptic plasticity-inhibiting drugs, transcranial magnetic stimulation, and by optimised psychotherapy.