Official data released under freedom of information rules highlights the pressure faced by UK military personnel with almost 800 incidents since April 2010.
The figures also show an average of one member of the forces commits suicide each month. Angus Robertson MP, the SNP's defence spokesman, called the figures "truly shocking".
He added: "We need to get to the bottom of what kinds of pressures are causing people to get into this terrible personal situation … we must find out from the Ministry of Defence what steps they are taking to help people."
An MoD spokesman said: "Good levels of mental health and well-being in the military have been achieved using a 'through-life approach' and the application of … measures based around a model of prevention, detection and treatment."