Can bipolar disorder cause seasonal mood changes?

Question

Hello doctor,

I really need some help understanding what is happening with me. I have had bipolar disorder since my late 20s, but over the last three winters, I have experienced very severe depressive episodes. I can barely get out of bed for weeks. Then, when spring arrives, my mood shifts in the opposite direction. I cannot sleep, and I start making impulsive decisions.

My psychiatrist adjusted my lithium dose last year, and my blood lithium level came back at 0.7 millimoles per liter (mmol/L), which she said was within the therapeutic range. However, I honestly do not feel well at all.

Why does bipolar disorder at 33 years of age cause such extreme seasonal mood changes every year, even when the medication levels appear to be appropriate on paper?

Kindly advise.

Answer 1

Hello,

Welcome to icliniq.com.

I have read your query and understand your concern.

Bipolar disorder can show a seasonal pattern in some individuals, meaning that depressive episodes may occur more commonly during the winter months, while manic or hypomanic episodes may develop during the spring or summer. These seasonal changes can occur even when the blood lithium level is within the recommended therapeutic range.

A level of 0.7 mmol/L for lithium is usually deemed therapeutic for most people. Yet, there will be varying levels of lithium in each patient, and some may still have their symptoms despite achieving an adequate blood level. It does not always mean that the drug is not working at all; sometimes, the treatment plan should still be adjusted.

Several factors can contribute to recurrent seasonal mood episodes, including incomplete response to lithium, rapid cycling bipolar disorder, psychosocial stress, disrupted sleep patterns, alcohol or recreational substance use, thyroid dysfunction, vitamin D deficiency, and changes in daylight exposure. Therefore, it is important to evaluate these possible contributing factors.

Your psychiatrist may consider adjusting the lithium dose if appropriate and safe, or adding another mood stabilizer or an atypical antipsychotic, depending on your symptoms and overall clinical assessment. Any changes to lithium should be made only under medical supervision, with regular check-ups of blood lithium levels, kidney function, and thyroid function.

Try to keep a mood diary and sleep diary can help identify patterns and provide valuable information during follow-up appointments. Psychological therapies, such as cognitive behavioral therapy (CBT) and Interpersonal and social rhythm therapy (IPSRT), can also be effective in reducing mood fluctuations and improving long-term stability.

Maintaining a consistent daily routine, especially regular sleep and wake times, avoiding alcohol and recreational drugs, managing stress, and attending regular psychiatric follow-up visits are all important parts of treatment.

If you experience worsening depression, suicidal thoughts, or symptoms of severe mania, such as risky behavior, marked agitation, or loss of touch with reality, seek immediate medical attention.

I hope this information is helpful. Please feel free to ask if you have any further questions.

Thank you.