Sleep and Circadian Rhythm Disruption in Social Jetlag and Mental Illness - Progress in Molecular Biology and Translational Science - page 336

A

Psychiatric
illness

Sleep and circadian
disruption

Stress axis
social isolation
medication

B

Stress axis
social isolation
medication

Common
overlapping
mechanisms

Sleep and
circadian
disruption

Psychiatric
illness

Cognitive/health problems
stress axis
developmental

Figure 11.7 Diagram illustrating the possible relationships between psychiatric illness
and sleep and circadian rhythm disruption (SCRD). (A) A straightforward and linear rela-
tionship whereby psychiatric illness results in SCRD as a result of activation of compo-
nents of the stress axis, an absence of social constraints and social isolation and/or is the
product of antipsychotic medication. (B) An alternative hypothesis which suggests that
psychiatric illness and SCRD share common and overlapping mechanisms. Thus, aber-
rant functioning or synchrony of specific neural circuits, affecting several neurotransmit-
ter systems that predispose an individual to psychiatric illness, will have a parallel effect
upon the sleep/circadian system. Disruption of sleep will, likewise, impact upon multiple
aspects of brain function, including activation of the stress axis, exacerbating or driving
a range of health problems ( Table 11.1 ) , and in the young, may have developmental
consequences. Medication, substance abuse, social isolation, and/or activation of the
stress axis associated with psychiatric illness will certainly impinge upon the sleep
and circadian systems, but are depicted here not as the primary cause of SCRD in neu-
ropsychiatric illness.

common in psychoses, or that disruption of sleep/circadian biology will, in
turn, have widespread effects, ranging across many aspects of neural and neu-
roendocrine function as outlined in Table 11.1 . Significantly, many of the
pathologies caused by SCRD are reported routinely as comorbid with neu-
ropsychiatric illness but are rarely linked to the disruption of sleep. Further-
more, the consequences of SCRD result in abnormal light exposure and
atypical patterns of social behavior ( Fig. 11.2 ) , closing a vicious cycle to further
destabilize sleep/circadian physiology. 35,36 The common and overlapping
mechanisms of psychosis and SCRD are illustrated in Fig. 11.7 B . Critically,
these relationships explain how relatively small changes in either the exoge-
nous social time or endogenous brain neurotransmitters will be amplified
by feedbacks to increase an individual's vulnerability to neuropsychiatric illness
and comorbid health problems. 1