Multihormonal responses to clonidine in patients with affective and psychotic symptoms

The neuroendocrine responses to the alpha(2)-adrenoreceptor agonist clonidi ne (CLO) (0.35 mg if body weight <65 kg or 0.375 mg if body weight greater than or equal to 65 kg, PO) were studied in a large group of subjects: 134 drug-free inpatients - with either DSM-IV schizophrenia (SCZ, n=31), schizo affective disorder (SAD, n=16), or major depressive episode (MDE, n=87)- an d 22 hospitalized controls (HCs). Comparison with a previous placebo test p erformed in a subgroup of 92 subjects (46 MDEs, 20 SCZs, 8 SADs, and 18 HCs ) showed that CLO induced a significant increase of growth hormone, prolact in (PRL) and thyrotropin (TSH) levels but no significant change in adrenoco rticotropin and cortisol release. According to diagnostic categories, we fo und significantly lower GH stimulation in MDEs and in SADs compared to HCs or to SCZs. in addition, we found significantly lower CLO induced PRL and T SH stimulations in paranoid SCZ patients compared to controls and disorgani zed SCZ patients. Taken together, these results suggest a hyposensitivity o f noradrenergic alpha(2)-receptors in patients with affective symptoms. (C) 2000 Published by Elsevier Science Ltd.