Diurnal changes in the frequency of panic attacks and symptoms of generalised anxiety, phobic anxiety and phobic avoidance in 34 panic-disorder patients and 40 normal controls were evaluated. The panic-disorder patients had significant diurnal changes in generalised and phobic anxiety, but not phobic avoidance. Increased severity of symptoms and prominent diurnal changes were most evident in the panic-disorder patients with a history of depression. Although panic attacks were distributed throughout the 24–hour period, patients with a current episode or history of depression tended to have more frequent panic attacks in the morning or early afternoon. These observations challenge the traditional belief that ‘anxious neurotic’ patients are relatively asymptomatic upon awakening in the morning and then develop more severe symptoms of anxiety later in the day.

The effects on serum electrolytes of carbamazepine, an acute and prophylactic treatment for manic-depressive illness, were assessed in subjects with primary affective disorder. Carbamazepine caused statistically significant, but clinically insubstantial, reductions in serum sodium and calcium, but not in the other electrolytes measured. Decreases in serum sodium and calcium were not related to carbamazepine dose, blood levels, or the degree of clinical improvement. The theoretical implications of these findings are discussed.

The definition and clinical aspects of rapid cycling affective illness are reviewed and various factors associated with the onset and maintenance of rapid cycling enumerated. On the basis of this information and of reports of the response of rapid cycling patients to various treatment interventions, an approach is suggested to the evaluation and treatment of rapid cycling affective illness.

We have observed a lesser growth hormone response to intravenous clonidine administration in nine obsessive-compulsive disorder patients meeting research diagnostic criteria than in nine matched controls. The obsessive-compulsive disorder patients had higher plasma free 3-methoxy-4-hydroxyphenylglycol and plasma norepinephrine levels before clonidine than the controls. As blunted growth hormone responses to clonidine are also characteristic of affective disorder patients, these results support other observations of a psychobiologic affinity between these two groups and are also compatible with an association between increased presynaptic noradrenergic activity and decreased post-synaptic receptor responsiveness.