Yes, it's real. Depression represses cognitive function, it affects your analytical ability as well as your perception.
The left hemisphere is about logic, numbers, sequencing. The right hemisphere is about feelings, imagination, intuition.
According to the hemisphere dominance, some people are left-brained, some people are right-brained and others (such as I) are balanced-brained, and the way they process information depends on this.
Different tasks affect different brain regions. Some occupations light up mostly the left hemisphere, others - the right.