Table 1.
Example studies of predictors for and early signs of bipolar illness episodes
| Study | Sample | Type of study | Assessment/diagnostics | Findings |
|---|---|---|---|---|
| Significant predictors of recurrent illness episodes in BD | ||||
| Martinez-Aran et al. (2004) | 40 euthymic BD patients 30 HC |
Cross-sectional study | Neuropsychological test battery on premorbid IQ, attention, verbal learning and memory and frontal executive functioning; symptomatology | Euthymic BD patients showed impairments in memory and executive functions. Verbal memory impairment was associated with worse functional outcome, longer illness duration, increased number of manic episodes and prior psychotic symptoms |
| Finseth et al. (2012) | 140 BD-I patients 66 BD-II patients |
Retrospective, cross-sectional study | Network Entry Questionnaires including questions on demographic and clinical variables describing the course of the illness, PANSS | Number of hospitalisations due to depression was a significant risk factors of suicide attempts as well as comorbid alcohol/substance use and a history of antidepressant medication- and⁄or alcohol-induced affective episodes |
| Martino et al. (2009) | 35 euthymic BD patients | Prospective, neuropsychological study | Neurocognitive Battery (verbal memory, attention, executive functions) at study entry; life chart assessment during 12 month follow up; GAF and FAST assessment after 12 months | Predictors of functional outcome: impairments in verbal memory and attention, subsyndromal depressive symptomatology (43% variance explanation) |
| Martino et al. (2013) | 70 euthymic BD patients | Prospective neuropsychological study | Neurocognitive assessment at study entry and division into impaired and not-impaired group; life chart assessment during around 16 months | Patients with impairments in at least one neurocognitive domain showed higher risk to develop a recurrent illness phase compared with non-impaired patients |
| Sierra et al. (2007) | – | Literature review | Search of studies on prodromes preceding both manic and depressive phases | Most common prodromes for mania: increased activity, elevated mood, decreased need for sleep, more talkative, racing thoughts, increased self-esteem, distractibility, increased sex-drive, increased spending, irritability and alcohol abuse Most common prodromes for bipolar depression: depressive mood, loss of energy, concentration difficulties, negative thinking, decreased sleep, increased sleep, loss of interest in activities, weight loss, loss of appetite, alcohol abuse and suicidal ideas |
| Ambulatory assessment studies | ||||
| Knowles et al. (2007) | 18 euthymic BD patients 16 MDD patients 19 HC |
Diary study over 1 week | Self-esteem, positive and negative affect were assessed twice a day over 1 week | Greater instability of affect and self-esteem in remitted bipolar patients as compared with unipolar patients and controls |
| Havermans et al. (2010) | 38 euthymic BD patients 38 HC |
Experience sampling approach over 6 days | Negative and positive mood states and their reactivity to daily hassles and uplifts | In BD patients mean level of negative affect was higher and positive effect lower compared with healthy controls, reactivity to daily hassles was comparable in both groups; subsyndromal depression increased perceived stress |
| Gruber et al. (2013) | 31 euthymic BD-I patients 21 remitted MDD patients 32 HC |
Experience sampling approach over 6 days | Consecutive assessment of emotionality (positive and negative) and use of emotion regulation strategies | BD-I patients showed increased positive and increased negative emotionality and increased efforts to regulate emotions in everyday life |
| Myin-Germeys et al. (2003) | 42 NAP patients 38 BD patients 46 MDD patients 49 HC |
Experience sampling approach | subjective stress reactivity daily hassles, emotional reactivity: changes in positive and negative affect | MDD patients showed an increase in negative affect and BD patients a decrease in positive affect in response to individually perceived stressful situations, whereas NAP patients reported both an increase in negative and decrease in positive affect |
NAP = non-affective psychosis; HC = healthy controls.