Inherited fear: could epigenetics provide mental health treatments?

According to a paper published in Nature Neuroscience, memories of traumatic odour exposure to acetophenone in mice have been shown to have been passed down generations. The mice in latter generations showed increased fearful behaviour to the chemical compound, despite having never encountered it before — a fear-potientated startle (FPS) reaction. In effect, this is compelling confirmation that memories can be inherited through ancestral rather than purely personal experience.

Evidence of non-Mendelian inheritance of behavioural traits in mammals has been accumulating, as epigenetics only started to come into its own as a research area in the mid 90s. For those that aren’t familiar with the area; epigenetics is effectively the response of our environment on DNA, without the alteration of gene expression itself. It involves the study of long-term alterations in chemical structures — histones and methylation of DNA in transcription. The area is currently stirring a flurry of interest with regards to the increased demand for personalised medicines as well as its relevance to a variety of clinical areas.

The paper makes a marked case for an increased understanding and insight into mental health areas, such as post-traumatic stress disorder (PTSD) and in effect how fear could be inherited. The question that I’m putting forward is, if it is possible to be conditioned into fear, could it be possible to be conditioned out of it through FPS as well? I would be curious to see future research considering and investigating other hypothesised innate emotions such as ‘sadness’. Depression can also have an environmental or psychological cause — potentially translating into epigenetics. Could olfactory conditioning through ‘smell’ and FPS be a new adjuvant treatment or cure to depression in future generations, for example?