Depression is a common but serious disease that frequently has major repercussions for patients, their families and the community alike. Because medical science still does not fully understand the etiology of depression and the associated mechanisms in the brain, identifying preventive interventions that work and providing effective care remain a difficult proposition.
Recent research suggests that depression is the result of a complex interplay between congenital or early acquired vulnerabilities and subsequent risk factors. After have examined factors associated with depression, researchers at Sahlgrenska Academy, University of Gothenburg, were able to show that lower than median birth weight and shorter gestational time increase the risk of depression later in life.
The findings, which have been presented in a doctoral thesis, are based on data generated by a 40-year study that followed 1,462 Gothenburg women born in 1908-1930.
“It has long been known that depression is twice as common in women as men,” says Dr. Pia Gudmundsson, one of the researchers. “Forty-five per cent of the women we studied had experienced depression at one point or another in their lives. Now we have demonstrated that women who weighed 3.5 kg or less at birth ended up developing depression more often than others and that shorter gestational time also appears to be a risk factor later in life”.
“Most people with lower than median birth weight never have depression and there are many other factors that affect mental health more. Also, all studies in this field do not find an association between birh factors and depression. That said, birth weight and gestational time are indirect measures of fetal health, and we have concluded that events early in life are associated with risks that emerge later on” Dr Gudmundsson continues.
Dr. Gudmundsson and her fellow researchers also studied a number of proteins in the cerebrospinal fluid that are associated with degeneration of neurons in the brain and that have been shown to be biomarkers for dementia. They were able to demonstrate that people with depression have elevated levels of these proteins (amyloid beta 42 peptide and Neurofilament-L) .
“Population studies have not reported these kinds of results earlier,” Dr. Gudmundsson says. “Because we conducted a cross-sectional study, however, we could not establish a causal relationship. In other words, we still do not know whether depression produces changes in the biomarkers or vice versa. Additional research will be required before any meaningful conclusions can be drawn.”
The doctoral thesis, which is entitled Factors Related to Depression in Women – over the Life Course was presented in October.