Smaller babies prone to depression, study finds

Smaller babies prone to depression, study finds
Baby girl Nadia (L), who weighed 7.75 kg (17.1 lbs) after birth, lies in a maternity ward in the Siberian city of Barnaul Sept. 26, 2007. Plump babies may really be happier babies, Canadian and British researchers reported on Monday in a study that found people who had a low birth weight were more likely to have depression and anxiety later in life. (Andrey Kasprishin/Reuters)WASHINGTON (Reuters) - Plump babies may really be happierbabies, Canadian and British researchers reported on Monday ina study that found people who had a low birth weight were morelikely to have depression and anxiety later in life.
Adverse conditions in the womb that interfere with a baby'sgrowth may also cause brain differences, the researchers reportin the December issue of Biological Psychiatry.
Ian Colman of the University of Alberta and colleagues inBritain studied the records of 4,600 Britons born in 1946 whotook part in a 40-year study.
"We found that even people who had just mild or moderatesymptoms of depression or anxiety over their life course weresmaller babies than those who had better mental health," Colmansaid in a statement.
"It suggests a dose-response relationship. As birth weightprogressively decreases, it's more likely that an individualwill suffer from mood disorders later in life."
The researchers simply looked at medical records and didnot examine a possible cause. Colman said it is possible thatwhen mothers are stressed, stress hormones are passing throughthe placenta to the fetus.
"If this theory is correct, you would find that whenstressful events occur, the people who were smaller babieswould be more likely to become depressed or anxious," he said.
"One of the surprising findings from our research was thatpeople who had worse mental health throughout their lives hadalso reached developmental milestones, like standing andwalking for the first time, later in life than those who hadbetter mental health."
The researchers did not look for any absolute weight butsaid there was a clear trend.
"Most notably, the group that had absence of symptoms hadthe highest birth weight, whereas the group with repeatedsevere symptoms had the lowest birth weight," they wrote.
"As weight at birth increased, the likelihood of symptomsof depression and anxiety across the life course decreased."
Not all small babies are fated to have poor mental health,the researchers said, noting that in 1946 records did notindicate whether the children were born prematurely.
"Being born small isn't necessarily a problem. It is aproblem if you were born small because of adverse conditions inthe womb -- and low birth weight is what we looked at in thisstudy because it is considered a marker of stress in the womb,"Colman said.
"When a mother is really stressed, blood flow to the uterusis restricted and the fetus gets fewer nutrients, which tendsto lead to lower birth weight."
Other studies have linked low birth weight to a higher riskof diabetes and heart disease in later life.
"I have been asked by many people what the 'take-homemessage' of this study is, and I would say that, in thesimplest terms, it is 'We should take better care of pregnantwomen,"' Colman said.
(Reporting by Maggie Fox, editing by Will Dunham and JohnO'Callaghan)