Mental health first aid

SIR – Professor Mark Watson-Gandy and others (Letters, November 18) argue that mental health first aid in the workplace should be compulsory. This is admirable, but the lack of working definitions could be problematic.

For instance, what counts as “good mental health” and “a mentally healthy environment”? Physical first-aiders rarely need to debate when to apply a waterproof plaster. Mental health is much more complex. Neil Richardson

Huddersfield, West Yorkshire