It may be useful to consider the application of Huang & Bargh's (H&B's) theory of unconscious motivational processes to psychopathology. In disorders of compulsivity and impulsivity, an unconscious habit system may play a key role in explaining ego-dystonic or self-destructive behaviour. H&B's theory may provide some insights into understanding conditions such as obsessive-compulsive disorder (OCD) and drug addiction; however, additional work is needed to address the neurocircuitry and neurochemistry mediating their abnormal underlying motivational processes.