How does intelligence relate to mental health symptoms? A study of Nigerian twins finds that higher intelligence is a protective factor against mental health problems. 
The study showed that:
Cognitive ability moderated externalizing problems, which means that less intelligent adolescents were more vulnerable to negative environmental influences. Smarter adolescents were better able to cope with a negative environment (or even avoid it completely).
The genetic effects were independent for cognitive ability and externalizing problems.
In less intelligent adolescents, negative externalizing behaviors had a strong family- and individual-level environmental influence. But in smarter adolescents, externalizing behaviors were the result of genetic and individual-level environmental influences.
This is an interesting study that sheds light on how mental health behaviors (in this case, externalizing behaviors (e.g., aggressiveness, conduct problems, impulsivity) relate to intelligence. It also says that “resilience” may not be a separate ability; it may just be a manifestation of high intelligence that helps people deal with a bad environment.
Link to full study: Redirecting