Comorbid substance use accounted for part but not all of the
observed associations between mental disorders and accidental
death. We found that various mental disorders were strongly
associated with death from poisoning or falls, and modestly
associated with transport accident death, even after accounting
for substance use. Several other mechanisms may contribute to
these risks. Common symptoms of psychiatric illness, such as
fatigue, poor concentration and sleep disturbance, may increase
the risk of accidents through impaired judgement, coordination
and reaction time.25–28 Psychiatric medications may also
contribute to these risks through common side-effects, or
unintentional overdose resulting from confusion or an effort to
relieve symptoms of the underlying disorder.8 Some mental
disorders are associated with risk-taking or self-destructive
behaviour that may occur on a continuum from subintentional
to intentional, increasing the risk of either accidental death or
suicide.5,6 Studies with more detailed clinical information will
be needed to elucidate the relative contributions of these factors
for specific types of accidental death