This is a comprehensive review of biological abnormalites observed in bipolar/unipolar mood disorder. We do not ignore that conflicting results may be found in the literature, but attempted, nevertheless, to summarize the currents trends.

This is a comprehensive review of biological abnormalities observed in bipolar/unipolar mood disorders. We do not ignore that conflicting results may be found in the literature, but attempted, nevertheless, to summarize the currents trends. Hypotheses: decreased sensitivity of pituitary glucocorticoid receptors to dexamethasone and/or hyperresponsivity of the adrenal gland to ACTH stimulation and/or hypothalamic CRH hyperactivity. Hypothesis: downregulation of pituitary TRH receptors secondary to a prolonged increase in endogenous TRH stimulation Dopamine (DA) Blunted PRL response to Normal PRL, GH, cortisol, and ACTH apomorphine 3 response to apomorphine Hypothesis: hyposensitivity of postsynaptic pituitary D 2 receptors Norepinephrine (NE) Blunted GH response Blunted GH response to clonidine to clonidine 4 Hypothesis: hyposensitivity of postsynaptic Ͱ 2 adrenoreceptors The following have been found inconsistently and nonspecifically in bipolar/unipolar depression: (i) blunted PRL and/or cortisol response to d,l-or d-fenfluramine, mCPP, clomipramine, 5-HT 1A agonists; (ii) blunted PRL and GH response to L-tryptophan Hypothesis: decreased presynaptic 5-HT activity and/or decreased sensitivity of postsynaptic 5-HT 1A receptors MONOAMINES Norepinephrine (NE) Low levels of urinary, plasma, Increased urinary NE, NMN, and CSF MHPG 5 and MHPG levels Increased plasma NE and CSF MHPG levels Hypothesis: decreased Hypothesis: increased presynaptic NE activity presynaptic NE activity Serotonin (5-HT) The following have been found inconsistently and nonspecifically for bipolar/unipolar depression: low urinary, plasma, and CSF 5-HIAA levels (dec-creased presynaptic 5-HT activity) Decreased CSF HVA levels in retarded patients (deccreased presynaptic DA activity)