introversion
The personality traits that are linked to both good and bad mental health.

People who are extraverted - self-confident and cheerful - are less likely to suffer mental health problems, personality research finds.

However, people who are aggressive and neurotic - a tendency to worry and be emotionally unstable - are at higher risk of mental health problems.

Neurotic people are more likely to suffer from depression and anxiety, as well as drink and drug problems.

Neuroticism, like other aspects of personality, is highly heritable - in other words, it is in a person's genes. However, neuroticism can be reduced by psychotherapy.

Neurotic people can learn to think differently, use their neuroticism creatively and perhaps reduce their neuroticism by falling in love.

The conclusions come from almost 600 participants in Switzerland. They were regularly interviewed from the age of around 19 in 1979, until they were in their 50s in 2008.

The researchers asked them about their mental health, personality, families, any problems with drugs and major life events like job losses, relationship break-ups and so on.

People who are aggressive, neurotic and introverted are particularly at risk, the study's authors write:
"...persons scoring high on aggressiveness and neuroticism and low on extraversion had an approximately 6 times increased risk for internalising disorder [like depression and anxiety] compared to persons scoring low on aggressiveness and neuroticism and high on extraversion."
Naturally, personality is not the only factor that affects whether a person develops a mental health problem. Some people's lives are much more difficult than others.

While one person lives in the lap of luxury, another is poor, isolated and beset by bad luck.

The researchers found that people who experienced job losses and relationship break-ups were more likely to suffer from depression and anxiety.

Personality, though, changes how people interpret and deal with the things that happen to them.

The study's authors conclude:
"Our findings stress the fundamental role of personality, mainly neuroticism, for the occurrence, persistence and severity of psychopathology."
The study was published in the journal European Archives of Psychiatry and Clinical Neuroscience (Hengartner et al., 2017).