In the Dennis Lab, we study psychiatric conditions like depression, neurodegenerative conditions like Alzheimer’s disease, and the relationship between psychiatric and neurodegenerative conditions.

Psychiatric Conditions:

Psychiatric conditions, such as depression, eating disorders, and attention deficit / hyperactivity disorder, are mental health conditions that affect a person’s thinking, feeling, mood, and behaviour. These conditions can significantly impact daily functioning and overall wellbeing. These conditions also typically manifest differently from one person to another, especially with regards to time. For example, one person may develop depression in their early teens that resolves with treatment, while another person may develop depression in their mid-sixties, with persistent, treatment-resistant symptoms that co-occur with declining cognitive function.

Neurodegenerative Conditions:

Neurodegenerative conditions, such as Alzheimer’s disease and Parkinson’s disease involve the gradual loss of brain function, affecting memory, cognitive abilities, mood, behaviour, and movement. When these changes are significant enough to affect daily life, dementia is diagnosed. Neurodegeneration in dementia begins up to two decades before diagnosis. Therefore, in the Dennis Lab, we also look at memory, cognitive, and mood changes that accompany aging, so that we can stop the progression of neurodegenerative conditions.

How do genetics influence brain related traits?

Psychiatric and neurodegenerative conditions are highly heritable, which means that at the population level, genes are a major driver of differences in who does and does not develop each condition in their lifetime. Heritability studies estimate that 30-80% of the between-person difference in risk for these conditions is due to between-person differences in genotype.

In the Dennis Lab, we aim to better understand the specific genetic factors that associate with how psychiatric and neurodegenerative conditions change over time, so that we can develop better prevention and treatment strategies.

Example of a project centered on psychiatric conditions in the Dennis Lab:

Impact of genetic factors for Anorexia nervosa in the first decade of life

Eating disorders are serious psychiatric conditions with major physical and psychosocial impacts. Anorexia nervosa (AN), marked by extreme energy restriction, fear of weight gain, and distorted body image, has one of the highest mortality rates among psychiatric disorders. Genes account for 48-74% of AN risk, and a recent genome-wide association study (GWAS) found significant genetic overlap between AN and traits like body mass index (BMI). We are now studying how genetic factors for AN affect growth and psychopathology in the first decade of life, before typical AN onset, using multiple complementary approaches and datasets.