Wives appear to influence their husbands' marijuana use, but the reverse does not hold true for husbands, says a US study.

Researchers said data collected showed that in the first year of marriage for 20-somethings, husbands were more likely to start or resume smoking marijuana if their wives smoked marijuana. Husbands also were more likely to stop smoking marijuana if their spouses did not smoke.

The reverse was not true in either case; husbands did not seem to influence their wives' marijuana smoking.

Researchers led by Kenneth E. Leonard in the Department of Psychiatry in the University at Buffalo School of Medicine and Biomedical Sciences studied couples recruited while applying for marriage licences since 1990, says a report in university website .

They collected data from 634 couples, 471 of whom provided data before marriage, at their first anniversary and at their second anniversary.

The researchers, however, said their findings may not generalise to other young adults who use drugs and are not married.