Bipolar Disorder

Bipolar disorder is an episodic illness of mood, energy, sleep, cognition, and behaviour. A patient in mania may be awake for days, convinced of extraordinary abilities, unable to judge consequences, and increasingly vulnerable to exhaustion, dehydration, accidental injury, exploitation, or conflict. A patient with bipolar depression may be slowed, hopeless, and at high risk of suicide. Mixed features can combine depressive despair with manic activation, making risk especially difficult to predict. The illness is highly heritable, with estimated heritability of roughly 60–85%, but it is not adequately explained by a single neurotransmitter deficiency. Genetic findings implicate, among others, ion-channel and cytoskeletal genes such as CACNA1C and ANK3. Disturbed circadian rhythms, dopaminergic signalling, mitochondrial energy production, oxidative stress, inflammation, and HPA-axis regulation converge to produce episodes that can disrupt the whole body, not just mood. For the RN, the central question is not simply, What mood does this patient report? It is, What state is the patient in, what danger follows from that state, and what treatment-related harm could imitate or worsen it? That question guides assessment, environmental control, medication monitoring,...