Although the link between depression and poor parenting has previously been identified, this is the first time that researchers have brought together multiple studies in order to identify the reasons behind the parenting difficulties.

The editorial, published in the journal Psychological Medicine, indicates that parents who experience depression might be emotionally unavailable and as a consequence feel shame and guilt towards their parenting role.

The work also indicates that problems with memory -- a symptom of depression -- may affect a parent's ability to set goals for their child at the appropriate developmental stage.

In the weeks after birth a mother's interaction with her child leads to structural changes in the brain which helps her respond to the needs of the infant. These changes may also occur in fathers. If depressed parents have not had optimal and frequent interactions with their newborns they may not develop these brain changes, resulting in parenting difficulties that can ultimately lead to a child with behavioural problems.

Dr Lamprini Psychogiou from the University of Exeter said: "We have looked at a wide range of research studies and identified multiple factors that link depression in adults to difficulties in their parenting role.

"This work will help identify areas in which future research is necessary in order to develop interventions that will prevent mental health issues from being transmitted from one generation to the next. We hope that this will go some way towards helping both depressed parents and their children."

Future research will test the mechanisms that link depression in adults with the difficulties they may have with parenting. An improved understanding of these processes will aid the development of more specific and potentially more effective treatments.