most other substance/medication -induced mental disorders, re gardless of the severity of
the symptoms, are likely to impr ove relatively quickly with ab stinence and unlikely to re-
main clinically relevant for more than 1 month after complete cessation of use.
As is true of many consequences of heavy substance use, some individuals are more
and others less prone toward specific substance-induced disorders. Similar types of pre-
dispositions may make some individuals more likely to develop psychiatric side effects of
some types of medications, but not others. However, it is unclear whether individuals
with family histories or personal prior hist ories with independent psychiatric syndromes
are more likely to develop the induced synd rome once the consideration is made as to
whether the quantity and frequency of the substance was sufficient to lead to the devel-
opment of a substanc e-induced syndrome.
There are indications that the intake of su bstances of abuse or some medications with
psychiatric side effects in the context of a pree xisting mental disorder is likely to result in
an intensification of the preexisting indepe ndent syndrome. The risk for substance/med-
ication-induced mental disorders is likely to increase with both the quantity and the fre-
quency of consumption of  the relevant substance.
The symptom profiles for the substance/medication-induced mental disorders resem-
ble independent mental disorders. While the symptoms of substance/medication-in-
duced mental disorders can be identical to those of independent mental disorders (e.g.,
delusions, hallucinations, psychoses, major de pressive episodes, anxiety syndromes), and
although they can have the same severe conseq uences (e.g., suicide) , most induced mental
disorders are likely to improve in a matt er of days to weeks of abstinence.