result in a hyperactive immune system. Patients with a mood disor-
der called atypical depression also have a blunted stress response and
impaired cortico-releasing hormone secretion, which leads to
lethargy, fatigue, and increased eating that often results in weight
gain. Patients with other illnesses characterized by lethargy and fa-
tigue, such as chronic fatigue syndrome, fibromyalgia, and seasonal
affective disorder (SAD), exhibit features of both depression and a hy-
peractive immune system associated with low cortisol levels.
There is also evidence from animal and human studies that poor
development in the early years can lead to increased risk for alcohol
or drug addiction. As discussed in the section on brain development,
studies with rhesus macaque monkeys or rats show that inadequate
touch stimulation in the early period of development influences the
risk for both behavior and alcohol addiction problems in later life.
In studies of the Kaiser Permanente program in California, it was
found that individuals who had been exposed to child neglect and
abuse when young were at high risk for drug and alcohol addiction in
adult life.
In reviewing all of the available evidence about early childhood
and health, Sir Donald Acheson’s Commission on Inequalities in
Health in Great Britain (Acheson 1998) concluded—
Follow up through life of successive samples of births has pointed to
the crucial influence of early life on subsequent mental and physical
health and development.Early Child and Brain Development and Behavior
In discussing this subject it is usual to separate psychiatric and non-
psychiatric behavior problems. An alternate way of looking at this is
that because these various behavior disorders are in effect related to
similar brain pathways, they may more be a product of different ways
in which these brain pathways work and interact with each other. As
discussed in the health section, how the brain develops in the early
stages of life affects mental health problems later in life.
ADHD is a product of interaction between the environment and
genetic vulnerability (Biederman and Faraone 2005). The brain path-
60 J. Fraser Mustard