Bipolar disorder, unipolar depression and the Five-Factor Model of personality

We examined differences between personality characteristics of euthymic bipolar disorder patients (BD) (n = 34) and recovered unipolar depressed patients (UD) (n = 74) using the taxonomy of the Five-Factor Model of personality (FFM) as measured by composite scales derived from the NEO Personality Inventory (NEO PI) and the revised NEO PI (NEO PI-R). Euthymic BD patients scored significantly higher on the Openness (O) dimension and the Positive Emotions facet of the E dimension than did recovered UD patients. For O, euthymic BD patients scored higher on the Feelings facet. These results suggest not only that euthymic BD patients are more likely to experience positive affects than recovered UD patients, but also that euthymic BD patients are more receptive to their positive and negative feelings than are recovered UD patients.

Seasonal and non-seasonal depression and the five-factor model of personality

The purpose of this study was to compare the personality characteristics of patients with non-psychotic, major depression, seasonal subtype (SAD) to patients with non-psychotic, major depression, without seasonality (non-SAD). The patients were consecutive referrals to a university-affiliated mood disorders outpatient clinic. The personality characteristics were assessed using the five-factor model of personality (FFM) as measured by the revised NEO Personality Inventory (NEO PI-R). Patients were assessed during the acute depressive episode. Controlling for severity of depression, differences were found on only one of the five dimensions, with the SAD patients (n = 43) scoring significantly higher on the Openness dimension than non-SAD patients (n = 57). Based on these results we infer SAD patients may represent a psychologically distinct subgroup of depressed patients-more imaginative, more emotionally sensitive and likely to entertain unconventional ideas than non-SAD patients. This personality constellation may explain why individuals with SAD are more sensitive to and may amplify the mild dysphoria typically associated with winter months.

A controlled comparison of light box and head-mounted units in the treatment of seasonal depression

BACKGROUND

Patterns of response to the light box and head-mounted unit (HMUs) in seasonal affective disorder (SAD) appear to differ. The current study employed a "no light" condition to compare the response rates with the light box and HMU against a plausible placebo.

METHOD

Forty-three subjects with DSM-III-R nonpsychotic, unipolar major depression, seasonal subtype, were randomly assigned, in a double-blind manner, to receive 2 weeks of active treatment with a light box (N=9) or HMU (N=12) that emitted no visible light, or 2 weeks of placebo treatment with a light box (N=12) or HMU (N=10) that emitted no visible light. Response was defined as a 50% or greater reduction in both the 17-item "typical" score and 8-item "atypical" score on the Structured Interview Guide for the Hamilton Rating Scale for Depression-SAD version (SIGH-SAD).

RESULTS

Using ANOVA for repeated measures, with change in total SIGH-SAD score as the dependent measure, we found no significant main effect of light (F=0.20, p=N.S.) or unit (F=0.50, p=N.S.), and no interaction (F=0.21, p=N.S.). Using log-linear analysis, we found no significant difference in response rate between the four cells (likelihood ratio chi-square = 2.1, p=N.S.). Using chi-square analysis, we found no significant difference in response rates between patients who received light (48%) versus patients who received no light (41%; chi-square = 0.2, p=N.S.) or between patients who received the light box (38%) versus HMU (50%; chi-square = 0.62, p=N.S.).

CONCLUSION

The failure to detect any significant difference in efficacy between active and placebo treatments calls into question the specificity of light in light therapy for SAD. Methodological limitations, particularly small sample size, are discussed.

Response to an open trial of a second SSRI in major depression

BACKGROUND

We evaluated the efficacy of a second serotonin selective reuptake inhibitor (SSRI) in patients who had failed to respond to the first SSRI used.

METHOD

Fifty-five patients with major depression who had failed one of the SSRIs for their current depressive episode were included. After failing a trial of one SSRI, they received a second SSRI in an open clinical trial.

RESULTS

On the basis of the Clinical Global Impression-Improvement scale, 28 of 55 patients had a marked or complete antidepressant response.

CONCLUSION

These data provide preliminary clinical evidence that substituting a second SRI may be a useful clinical alternative in depressed patients who fail to respond to an adequate trial of an SSRI.

Augmentation strategies: focus on anxiolytics

Approximately 20% to 40% of patients will fail to respond to the first antidepressant used for their current major depressive episode. Furthermore, it has been suggested that a further 20% to 30% of patients will have only a partial response. There are four main options to consider in the treatment of these patients: optimization, substitution, augmentation, and combination therapy. Several combination antidepressant treatments have been used in treatment-refractory depression. Moreover, various augmentation strategies have also proved to be successful. Although the empirical data to support these treatment options are limited, augmentation treatment has several potential advantages over the other clinical options available, particularly substitution. These data are reviewed and clinical applications discussed. Particular attention is paid to the role of anxiolytics as augmentation agents in the treatment of major depression.

Serum Mg2+ and Ca2+/Mg2+ ratio in major depressive disorder

Serum Mg2+ has been implicated in the symptom severity and pathophysiology of mood disorders. Furthermore, the recent findings of blunted signalling through the G-protein-coupled adenylyl cyclase (AC) pathway in major depressive disorder (MDD) and the importance of Mg2+ in G-protein/AC function led us to reexamine in a large sample whether serum Mg2+ concentrations were decreased in MDD patients. In 145 drug-free MDD patients compared with 2 control groups: (a) patients with bipolar disorder (n = 33) and (b) non-mood-disordered patients (n = 47), there were no differences in Mg2+ levels or Ca2+/Mg2+ ratios. Neither of these measures differed when comparing responders and nonresponders to antidepressant treatment.

Multicenter, placebo-controlled study of fluoxetine in seasonal affective disorder

OBJECTIVE

The authors investigated the efficacy and safety of fluoxetine in the treatment of winter seasonal affective disorder.

METHOD

Sixty-eight outpatients who met the DSM-III-R criteria for recurrent major depressive episodes, seasonal (winter) pattern, were randomly assigned to 5 weeks of treatment with fluoxetine, 20 mg/day (N = 36), or placebo (N = 32). The outcome measures included the 29-item modified Hamilton Depression Rating Scale, administered by experienced clinicians, and the self-rated Beck Depression Inventory; adverse events and safety data were also recorded. Clinical response was defined as a greater than 50% reduction in depression score between baseline and study termination.

RESULTS

Both groups showed significant improvement. The fluoxetine group had lower depression scores at termination than the placebo group, but these differences did not achieve statistical significance. However, the rate of clinical response in the fluoxetine group (59%) was superior to that in the placebo group (34%). Post hoc analyses showed that the greatest fluoxetine responses were in the most markedly depressed patients and that overall response was greater for patients studied later in the season. Fluoxetine was well tolerated, and few subjects dropped out because of adverse events.

CONCLUSIONS

On the basis of clinical response rate, fluoxetine appears to be an effective, well-tolerated treatment for seasonal affective disorder. Because the differences between fluoxetine and placebo in the continuous outcome measures did not reach statistical significance, further studies with larger study groups and longer treatment periods are required to conclusively demonstrate efficacy of fluoxetine for seasonal affective disorder.

Treatment of seasonal affective disorder: a review

OBJECTIVE

To review the status of current treatment of seasonal affective disorder (SAD).

METHOD

Treatment studies of SAD published between January 1989 and March 1995 were identified using a computerized MEDLINE literature search. Additional citations were obtained from the reference sections of these articles. Studies included in this review were selected using operational methodologic criteria.

RESULTS

Many studies support the efficacy of bright light therapy using a fluorescent light box. The best studied protocol is > 2500 lux white light for 2 hours per day, but newer protocols using 10,000 lux for 30 minutes have comparable response rates. Studies of light visors and other head-mounted devices also report similar response rates, but have not yet shown superiority over putative control conditions. There are fewer medication studies in SAD, but controlled studies suggest that fluoxetine, d-fenfluramine and propranolol are effective. Other treatments such as dawn simulation require further study. No studies of psychological treatments for SAD were found. Many studies had methodologic limitations, including brief treatment periods, small sample sizes, and lack of replication, that limit the generalizability of findings.

CONCLUSION

There are several well-studied, effective treatments for SAD, including light therapy and medications. However, further research must be done to demonstrate sustained treatment response over time, to clarify the intensity-response relationship of light therapy, to clarify the role of light therapy and medications, and to assess combination treatments.

A comparison of Tridimensional Personality Questionnaire dimensions in bipolar disorder and unipolar depression

The harm avoidance (HA) personality dimension has been hypothesized to be a vulnerability factor for unipolar depression (UD) but not for bipolar disorder (BD). The reported difference on HA scores between these diagnostic groups may have been compromised by the assessment of BD patients who had not fully recovered. To test the diagnostic specificity of elevated HA scores and to elucidate whether assumptions about differences between patients with UD or BD might be attributed to the lingering effects of mood state, the Tridimensional Personality Questionnaire (TPQ) was administered to recovered patients with either BD or UD and a nonpatient comparison group. Both patient groups scored higher on the HA dimension than the nonpatient comparison group, but the patient groups did not differ from one another on this dimension. Moreover, novelty seeking (NS) scores were elevated in subjects with BD compared with both UD patients and nonpatient subjects. These results suggest that high HA scores may be associated with a mood disorder diagnosis, whereas high NS scores may be associated with the BD subtype.

Seasonal fluctuations in mood and eating behavior in bulimia nervosa

Thirty-five bulimia nervosa (BN) patients with high seasonality scores on a modified version of the Seasonal Pattern Assessment Questionnaire (SPAQ) were administered semistructured clinical interviews to further assess their seasonal symptom patterns. A diversity of patterns were identified, consistent with a multidimensional model of seasonality in the BN population. Overall, the results suggest that seasonality may be an important dimension to consider in patients with BN.

Change in folate status with antidepressant treatment

Ninety-nine consecutive unmedicated outpatients with a major depressive illness had blood drawn for measurement of serum folate (SF), red cell folate (RCF), and vitamin B12 within 24 hours of completion of ratings of severity of depression at the beginning and ending of a 5-week trial of desmethylimipramine (mean dose = 149.2 mg/day, range = 75-225 mg). As compared with nonresponders, responders had a significantly higher mean SF at baseline (nonresponders = 13.8 nmol/l; responders = 17.7 nmol/l) and RCF showed a significant inverse correlation with severity of depression and a significant positive correlation with age of onset of illness. At week 5, change in severity of depression was significantly correlated with change in RCF, and significantly more responders than nonresponders had an increase in RCF. The possible role of folate status in the regulation of mood and response to treatment is discussed.

Dim versus bright red (light-emitting diode) light in the treatment of seasonal affective disorder

Forty-three subjects with seasonal affective disorder were randomly assigned to receive 2 weeks of treatment with either bright- (mean 4106 lx) or dim-light (mean 96 lx) therapy, using red light-emitting diode light sources, in a head-mounted unit. Defining response as a 50% reduction in the 21-item Hamilton Depression Rating Scale score to a post-treatment score of less than 8, there was no significant difference in response rate between patients receiving bright light (67%) as compared with patients receiving dim light (68%). Possible explanations for the similar response rate to 2 very different illuminances of red light are discussed.

Is hypersomnolence a feature of seasonal affective disorder?

We examined hypersomnolence as experienced among individuals meeting standardized diagnostic criteria for Seasonal Affective Disorder (SAD). Data were available from 115 individuals attending a mood disorders clinic specializing in treatment of this disorder. Three modes of assessment were employed: retrospective self-reports (Seasonal Patterns Assessment Questionnaire), cross-sectional interviews (Standardized Interview Guide for the Hamilton Depression Scale, SAD Version), and prospective sleep diaries. Results indicated that self-reported total hours of sleep varied significantly across the seasons, with longest sleep occurring in winter and shortest sleep in summer. Seasonal sleep changes, as indicated by the SPAQ did not correlate significantly, however, with severity of depressive symptoms as indicated by the Hamilton scale. Multiple regression analyses indicated that only social activity levels (one of seven SPAQ items) was significantly and uniquely related to the severity of depression. When data obtained by the three instruments were compared, self-reported hours of sleep (whether measured by SPAQ or Hamilton interview) were significantly higher than indicated by prospective sleep diaries. We conclude that hypersomnolence may not be a central feature of SAD and that the validity of the SPAQ as an index of this disorder requires further investigation.

Predictors of response to lithium and triiodothyronine augmentation of antidepressants in tricyclic non-responders

Although both lithium and triiodothyronine (T3) augmentation strategies may be rapid, safe, and effective ways of treating patients who fail to respond to tricyclics, little is known about the clinical or biochemical correlates of response. We examined clinical and endocrine variables which distinguished T3 and lithium responders from each other and from non-responders in a post-hoc analysis of two studies involving 51 subjects who had received these augmentation strategies under double-blind conditions. Lithium non-responders were more severely depressed and had more insomnia and weight loss than responders. T3 responders could be distinguished from lithium responders by greater weight loss. There were no reliable clinical differences between T3 responders and non-responders. Thyroid function tests did not differ between any of the treatment or response groups. Our findings suggest that clinical but not endocrine variables may distinguish responders to these two augmentation strategies.

A comparison of personality characteristics of seasonal and nonseasonal major depression

During the acute depressive episode, seasonal affective disorder (SAD) patients (N = 24) differ significantly from non-SAD major depressives (N = 17) on five of 13 personality variables measured, although severity of depression appears to be similar. SAD patients score significantly lower on the self-criticism and dependency dimensions of the Depressive Experiences Questionnaire (DEQ) and significantly higher on three personality trait scales (including schizotypal, narcissistic, and avoidant) of the Millon Clinical Multiaxial Inventory (MCMI). Our data suggest that those with seasonal depression may represent a psychologically distinct subgroup of depressives.

Anxious and non-anxious bipolar disorder

Eighty-one outpatients with bipolar disorder (BD) were grouped by SADS anxiety symptom scores (high vs. low) or diagnosis of generalized anxiety disorder, and/or panic disorder. BD patients with high anxiety scores were more likely to have suicidal behaviour (44% vs. 19%), alcohol abuse (28% vs. 6%), cyclothymia (44% vs. 21%) and an anxiety disorder (56% vs. 25%) with a trend toward lithium non-responsiveness. Diagnosis of an anxiety disorder was related only to high anxiety and lower GAS scores. Thus, anxiety may have similar clinical relevance in BD as it does in unipolar patients.

The Tridimensional Personality Questionnaire in major depression

The authors examined Tridimensional Personality Questionnaire scores in 40 patients with unipolar nonpsychotic major depression before and after antidepressant treatment. They found that scores on the novelty seeking and reward dependence dimensions were not affected by depressed state or by treatment response status. However, scores on the harm avoidance dimension were significantly lower in antidepressant responders and were altered by depressed state.

A placebo-controlled comparison of lithium and triiodothyronine augmentation of tricyclic antidepressants in unipolar refractory depression

OBJECTIVE

To directly compare the efficacy of lithium carbonate and liothyronine sodium (triiodothyronine) in the augmentation of therapeutic response in antidepressant nonresponders.

DESIGN

A randomized, double-blind, placebo-controlled study of 2 weeks' duration.

SETTING

The Mood Disorders Program, Clarke Institute of Psychiatry and the University of Toronto, Ontario.

PATIENTS

Fifty outpatients, males and females, with unipolar, nonpsychotic major depression who had failed to respond to treatment with desipramine hydrochloride or imipramine hydrochloride.

RESULTS

Both liothyronine and lithium were more effective than placebo in reducing scores on the Hamilton Rating Scale for Depression. However, the antidepressant augmenting effect of these two compounds did not differ from each other. When response was defined as a 50% or more reduction in the Hamilton Rating Scale for Depression scores and a final score less than 10, we found that 10 of 17 subjects responded to liothyronine, nine of 17 responded to lithium and three of 16 responded to placebo.

CONCLUSIONS

Our study suggests that both lithium and liothyronine may be considered as alternatives in augmenting antidepressant response in patients who do not respond to treatment with a tricyclic antidepressant.

Anxiety disorders and anxiety symptoms in a clinic sample of seasonal and non-seasonal depressives

Thirty-eight patients with seasonal affective disorder (SAD) were compared with 33 non-seasonal recurrent major depressives (non-SAD) who presented during the winter months for differences in the prevalence of concurrent anxiety disorders and the impact of anxiety on treatment response. SAD patients received light therapy, whereas non-SAD patients received antidepressant medications. There was no differences in the prevalence of any anxiety disorder, or on scores of anxiety on the Hamilton Rating Scale for Depression between the SAD and non-SAD groups. The presence of any anxiety disorder was associated with a better response rate in SAD patients, and an inferior response rate in non-SAD patients. The findings refute previous suggestions that anxiety is more common in SAD than in non-SAD, but suggest that the presence of anxiety may be associated with differential treatment response rates.

Side effects of light therapy in seasonal affective disorder

The authors report the frequency of side effects of light therapy in 105 patients with seasonal affective disorder treated with three intensities of light. Common symptoms to emerge during treatment were headache (19%), eyestrain (17%), and feeling "wired" (14%). There was no relationship between side effects and intensity of light used.