Title suggest causation, but reading the article it sounds like it's a contributing factor to preexisting mental health issues:
"What we see with unemployment is that it increases the risk because it makes already bad situations worse for some people," he said. "Any kind of economic strain or unemployment, to the degree that there are already mental health or substance abuse or relationship problems, can make it worse."
The interesting part is that it's saying that people unused to unemployment are more affected than those where unemployment I common.
So a country region,city where unemployment is already high, becoming unemployed there has less effect than exhibited in an area with traditionally high employment --people not acclimated to unemployment take the experience harder.
Exactly. Depressed people commit suicide, unemployment can exacerbate depression, thus it correlates with suicide rates. Not exactly a new finding but one to remember. More of a "hey look <bad thing> is <really bad>." with some numbers to make it more real to the reader.
"What we see with unemployment is that it increases the risk because it makes already bad situations worse for some people," he said. "Any kind of economic strain or unemployment, to the degree that there are already mental health or substance abuse or relationship problems, can make it worse."