Arthur Mackert

Phototherapy in nonseasonal depression

Previous reports have shown that bright light exposure may benefit patients with seasonal depression. In the present study, the possible therapeutic effect of bright light in nonseasonal major depressive disorder was examined. Forty-two depressed patients not receiving additional antidepressant medication were exposed to bright white light of 2500 lux or dim red light of 50 lux over one week for two hr daily in the morning. The change in depressive symptoms was assessed by rating scales (Hamilton Depression Rating Scale, CGI) and by self-rating scales (Depression Scale, Complaint List, Visual Analogue Scale). Consistent for all ratings, the decrease in depressive symptoms after bright white light was only slight and not different from dim red-light exposure. Contrary to the findings in seasonal affective disorder, phototherapy administered over one week for two hr daily is not effective in nonseasonal major depressive disorder.

Blood serotonin, serum melatonin and light therapy in healthy subjects and in patients with nonseasonal depression

The 24‐h rhythms of blood serotonin and serum melatonin were determined in 39 unmediated inpatients with nonseasonal affective disorder and in 14 healthy men and women after 7 days of morning bright‐light (2500 lx) or dim‐light (50 lx) treatment. Bright‐light treatment led to a more than 50% decrease in the Hamilton Rating Scale for Depression (HRSD) score in 4/19 patients and dim light in 1/17 patients. After light treatment the mesor (the daily mean estimated by cosinor analysis) of patients’ and subjects’ melatonin levels did not change significantly, nor was there a correlation between phase change and decrease in HRSD score. We observed after bright‐ and dim‐light treatment a consistent increase in blood serotonin in patients and healthy subjects, which differed significantly between healthy subjects and patients. These findings suggest the involvement of serotonergic mechanisms following light therapy.

Basic parameters of saccadic eye movements – differences between unmedicated schizophrenia and affective disorder patients

Background Smooth pursuit eye movement (SPEM) dysfunctions are considered a biological marker for schizophrenia and have been studied widely. In contrast, saccadic eye movements have received less attention, although disturbances have been described previously. Basic neurophysiologic parameters of saccades in schizophrenics, especially in unmedicated patients, have not been studied extensively. Methods Saccadic eye movements of 38 unmedicated schizophrenic patients, 32 patients with major depression and 42 non-psychiatric controls were examined using high-resolution infrared oculography. Two large-amplitude saccadic tasks were presented. The groups were compared on peak velocity, reaction time and accuracy. Results Peak velocity was significantly increased in schizophrenic patients. Depressive patients had a significantly longer reaction time. Both patient groups needed more corrective saccades to reach the target than controls. Conclusions Peak velocity distinguishes unmedicated schizophrenic patients from depressive patients and normal controls. This could be explained by deficits of the prefrontal cortex in the inhibitory control of saccades. Our findings suggest that schizophrenia affects not only SPEM but also saccadic eye movements.

Increased blink rates in schizophrenics. Influences of neuroleptics and psychopathology

During a standardized visuomotor task, eye blinking, a possible parameter of central dopaminergic activity, was studied in 18 previously medicated and eight drug-naive schizophrenic in-patients in the acute state and during remission. Whereas schizophrenics executed the visuomotor task with the same precision as age- and sex-matched normal control subjects did, the mean blink rate was increased in both schizophrenic groups. During neuroleptic treatment, the mean blink rate was reduced only in the group of drug-naive patients, but not in the previously neuroleptic treated schizophrenics. This varying blinking activity is discussed with respect to the development of neuroleptic tolerance and influence of psychopathology.

Saccadic reaction times in acute and remitted schizophrenics

SummarySchizophrenics are known to have various disturbances of the visuomotor system. Whereas smooth pursuit eye movement disorders have been repeatedly confirmed, there are relatively few reports regarding possible disturbances of the saccadic system. In this study, the saccadic reaction times of 47 schizophrenic inpatients were investigated upon admission and later in the remitted state; 28 age- and sex-matched normal volunteers were tested as controls. Psychopathology and outcome were evaluated according to the Brief Psychiatric Rating Scale and the Prognostic Scale. Light stimuli were presented at random direction, location (ranging from 0° to 20°) and duration (800, 1000, and 1200 ms). The eye movements were recorded by electro-oculography. Compared with the control group, schizophrenics revealed prolonged saccadic reaction times, which correlated with pronounced negative symptoms and an unfavourable course of the illness. The saccadic reaction times remained prolonged in schizophrenic patients. These findings suggest attentional deficits in schizophrenics.

Smooth pursuit eye movements of patients with schizophrenia and affective disorder during clinical treatment

Background Smooth pursuit eye movement dysfunctions are considered a biological indicator for vulnerability to schizophrenia. This study examines test-retest stability of specific eye movement variables such as velocity gain and different saccadic categories. Methods Smooth pursuit eye movements of 27 schizophrenic patients and 30 patients with major depression were examined three times during clinical treatment using high-resolution infrared oculography. Forty-one normal controls were retested after four weeks. Results Intraclass correlation coefficients as a measure for retest-stability were highly significant in each group for all time-points, except for anticipatory saccades in schizophrenics. No significant correlations were found between psychopathological status, neuroleptic medication and eye movement variables. Conclusions Our results indicate that the most important measures of eye tracking performance in psychiatric patients are not significantly influenced by neuroleptic medication or clinical state and are stable across time.

Effect of bright white light therapy on non-seasonal depressive disorder Preliminary results

In this study, the effect of bright white light (2500 lux) and dim light (50 lux) were assessed in 30 patients with non-seasonal major depressive disorder randomly assigned to either procedure. Patients met RDC for major depressive disorder and ICD-9 criteria (296.1 and 296.3). During a 7-day period, the patients were exposed to bright white light (2500 lux) or dim light (50 lux) from 7.00 to 9.00 h daily. The severity of depression was assessed with observer scales (AMDP system, Hamilton depression scale, CGI) and through self-evaluation by self-rating scales (depression scale and list of complaints by von Zerssen). No difference was noted between bright light therapy and dim light, though a significant reduction of depressive symptomatology was observed for all patients during the study. These findings are discussed from a clinical point of view.

Serum concentrations of thyroid hormones in patients with nonseasonal affective disorders during treatment with bright and dim light.

Serum concentrations of thyroxine (T4), triiodothyronine (T3), and thyrotropine were measured in 34 patients with nonseasonal affective disorders before and after 1 week of light treatment. Nineteen of these patients received bright white light (2500 lx) and 15 dim red light (50 lx) for 2 hours daily in the mornings over a 1-week period. Slight but significant reductions in the rating scores for the depressive symptomatology were found for both the bright-and dim-light groups, but there were no significant differences between the two groups. The improvement is thus most likely a placebo effect. Surprisingly, the small changes in the severity of the depressive symptoms in the group as a whole were significantly correlated to the changes in the serum levels of T4 during the weeks of bright- and dim-light treatment, respectively. The more a patient improved, the further his or her T4 level fell and vice versa. The fluctuations in the concentrations of T4 during light treatment were significantly greater in the depressed patients than in a group of 12 healthy controls who also received bright or dim light, whereas the changes in T3 were significantly smaller than those of the healthy controls. The pronounced fluctuations in T4 levels were probably not secondary to changes in mood. Rather, they are likely to reflect changes in tissue (intracellular) metabolism of T4, which may be involved in the mechanisms underlying the fluctuations in mood in these patients.

Diurnal variations of mood and sleep disturbances during phototherapy in major depressive disorder

The influence of diurnal variations of mood (DVM) and sleep disturbances on treatment response was investigated in 42 patients with major depressive disorder (not SAD) under the treatment of either bright white light (2,500 lx) or dim red light (50 lx). We found only a slight influence in certain subscales of DVM and no influence of sleep disturbances. These results are discussed under a clinical point of view and with respect to phase shift theories of depressive disorders.

Subthreshold symptoms and vulnerability indicators (e.g., eye tracking dysfunction) in schizophrenia.

Subthreshold symptoms in schizophrenia can be prodromal signs of a psychotic relapse. In people without schizophrenia, similar symptoms may indicate the presence of disorders termed schizophrenia spectrum disorders. Subthreshold schizophrenia-like symptoms may indicate a genetically transmitted higher proneness to schizophrenia. Such a higher liability to develop schizophrenia is ascertained on a symptom level. In genetic studies, asymptomatic members of a pedigree are therefore classified as unaffected although they may possess the genes in question. On a biological level, eye tracking dysfunction has been shown to fulfill certain criteria for a vulnerability indicator and therefore promises to offer more information on genetically transmitted proneness to schizophrenia even in people without psychopathological symptoms. Subthreshold symptoms may warrant treatment. The database for prophylactic treatment in populations at high risk, especially those without symptoms, is currently very small.